York DM120, DM150, DM090 User Manual

INSTALLATION
MANUAL - 50 Hz

®

SINGLE PACKAGE AIR CONDITIONERS AND

SINGLE PACKAGE GAS/ELECTRIC UNITS

CONTENTS

GENERAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

SAFETY CONSIDERATIONS. . . . . . . . . . . . . . . . . . . 5

INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

REFERENCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

RENEWAL PARTS. . . . . . . . . . . . . . . . . . . . . . . . . . . 6

APPROVALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

NOMENCLATURE . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

OPERATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

START-UP (COOLING) . . . . . . . . . . . . . . . . . . . . . . 45

START-UP (GAS HEAT) . . . . . . . . . . . . . . . . . . . . . 45

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . 50

See the following pages for a complete Table of Contents.

DM090, 120 AND 150

7-1/2, 10 AND 12-1/2 TON

(9.0 TO 10.0 EER) 50 Hz

NOTES, CAUTIONS AND WARNINGS

The installer should pay particular attention to the words:
NOTE, CAUTION, and WARNING. Notes are intended to
clarify or make the installation easier. Cautions
to prevent equipment damage. Warnings
installer that personal injury and/or equipment damage
may result if installation procedure is not handled properly.

CAUTION: READ ALL SAFETY GUIDES BEFORE YOU

BEGIN TO INSTALL YOUR UNIT.

SAVE THIS MANUAL

are given

are given to alert

127408-YIM-B-0606

TABLE OF CONTENTS

GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

SAFETY CONSIDERATIONS. . . . . . . . . . . . . . . . . . . . . 5

INSPECTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

REFERENCE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

RENEWAL PARTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

APPROVALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

NOMENCLATURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

INSTALLATION SAFETY INFORMATION . . . . . . . . . . . .8

PRECEDING INSTALLATION . . . . . . . . . . . . . . . . . . . . . . 8

LIMITATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

LOCATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

RIGGING AND HANDLING . . . . . . . . . . . . . . . . . . . . . . .10

CLEARANCES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

DUCTWORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

DUCT COVERS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

CONDENSATE DRAIN . . . . . . . . . . . . . . . . . . . . . . . . . .15

COMPRESSORS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

FILTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

THERMOSTAT WIRING . . . . . . . . . . . . . . . . . . . . . . . . .16

POWER AND CONTROL WIRING . . . . . . . . . . . . . . . . .16

POWER WIRING DETAIL . . . . . . . . . . . . . . . . . . . . . . . .16

OPTIONAL ELECTRIC HEAT . . . . . . . . . . . . . . . . . . . . .21

OPTIONAL GAS HEAT . . . . . . . . . . . . . . . . . . . . . . . . . .21

GAS PIPING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

GAS CONNECTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

LP UNITS, TANKS AND PIPING . . . . . . . . . . . . . . . . . . . . . . .23

VENT AND COMBUSTION AIR. . . . . . . . . . . . . . . . . . . . . . . .23

OPTIONS/ACCESSORIES . . . . . . . . . . . . . . . . . . . . . . .23

ELECTRIC HEAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

MOTORIZED OUTDOOR DAMPER . . . . . . . . . . . . . . . . . . . . 23

ECONOMIZER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

POWER EXHAUST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

RAIN HOOD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

ECONOMIZER AND POWER EXHAUST

SET POINT ADJUSTMENTS AND INFORMATION . . . . 24

MINIMUM POSITION ADJUSTMENT . . . . . . . . . . . . . . . . . . .24

ENTHALPY SET POINT ADJUSTMENT . . . . . . . . . . . . . . . . . 24

POWER EXHAUST DAMPER SET POINT

(WITH OR WITHOUT POWER EXHAUST) . . . . . . . . . . . . . . .24

INDOOR AIR QUALITY AQ . . . . . . . . . . . . . . . . . . . . . . . . . . .24

PHASING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

BLOWER ROTATION . . . . . . . . . . . . . . . . . . . . . . . . . . .26

BELT TENSION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

AIR BALANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

CHECKING AIR QUANTITY . . . . . . . . . . . . . . . . . . . . . .34

METHOD ONE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

METHOD TWO. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

SUPPLY AIR DRIVE ADJUSTMENT. . . . . . . . . . . . . . . .36

OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

SEQUENCE OF OPERATIONS OVERVIEW . . . . . . . . .40

COOLING SEQUENCE OF OPERATION. . . . . . . . . . . .40

CONTINUOUS BLOWER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

INTERMITTENT BLOWER. . . . . . . . . . . . . . . . . . . . . . . . . . . .40

NO OUTDOOR AIR OPTIONS. . . . . . . . . . . . . . . . . . . . . . . . .40

ECONOMIZER WITH SINGLE ENTHALPY SENSOR. . . . . . . 40

ECONOMIZER WITH DUAL ENTHALPY SENSORS . . . . . . . 40

127408-YIM-B-0606

ECONOMIZER WITH POWER EXHAUST. . . . . . . . . . . . . . . .41

MOTORIZED OUTDOOR AIR DAMPERS . . . . . . . . . . . . . . . .41

COOLING OPERATION ERRORS. . . . . . . . . . . . . . . . . . . . . .41

HIGH-PRESSURE LIMIT SWITCH. . . . . . . . . . . . . . . . . . . . . .41

LOW-PRESSURE LIMIT SWITCH . . . . . . . . . . . . . . . . . . . . . .41

FREEZESTAT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

LOW AMBIENT COOLING . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

SAFETY CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

COMPRESSOR PROTECTION . . . . . . . . . . . . . . . . . . . 42

FLASH CODES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

ELECTRIC HEATING SEQUENCE OF OPERATIONS . 42

ELECTRIC HEAT OPERATION ERRORS . . . . . . . . . . . 42

TEMPERATURE LIMIT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

SAFETY CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

LIMIT SWITCH (LS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

FLASH CODES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

ELECTRIC HEAT ANTICIPATOR SETPOINTS . . . . . . . 42

GAS HEATING SEQUENCE OF OPERATIONS . . . . . . 43

IGNITION CONTROL BOARD . . . . . . . . . . . . . . . . . . . . 43

FIRST STAGE OF HEATING . . . . . . . . . . . . . . . . . . . . . . . . . .43

SECOND STAGE OF HEATING. . . . . . . . . . . . . . . . . . . . . . . .43

RETRY OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

RECYCLE OPERATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

GAS HEATING OPERATION ERRORS . . . . . . . . . . . . . 43

LOCK-OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

TEMPERATURE LIMIT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

FLAME SENSE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

GAS VALVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

SAFETY CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

LIMIT SWITCH (LS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

AUXILIARY LIMIT SWITCH (ALS) . . . . . . . . . . . . . . . . . . . . . .44

PRESSURE SWITCH (PS). . . . . . . . . . . . . . . . . . . . . . . . . . . .44

ROLLOUT SWITCH (ROS). . . . . . . . . . . . . . . . . . . . . . . . . . . .44

INTERNAL MICROPROCESSOR FAILURE . . . . . . . . . . . . . .44

FLASH CODES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

RESETS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

GAS HEAT ANTICIPATOR SETPOINTS . . . . . . . . . . . . 44

START-UP (COOLING) . . . . . . . . . . . . . . . . . . . . . . . . 45

PRESTART CHECK LIST. . . . . . . . . . . . . . . . . . . . . . . . 45

OPERATING INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . 45

POST START CHECK LIST . . . . . . . . . . . . . . . . . . . . . . 45

START-UP (GAS HEAT) . . . . . . . . . . . . . . . . . . . . . . . 45

PRE-START CHECK LIST . . . . . . . . . . . . . . . . . . . . . . . 45

OPERATING INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . 45

LIGHTING THE MAIN BURNERS. . . . . . . . . . . . . . . . . . . . . . .45

POST START CHECKLIST. . . . . . . . . . . . . . . . . . . . . . . 45

SHUT DOWN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

MANIFOLD GAS PRESSURE ADJUSTMENT . . . . . . . . 46

CHECKING GAS INPUT. . . . . . . . . . . . . . . . . . . . . . . . . 46

NATURAL GAS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46

ADJUSTMENT OF TEMPERATURE RISE. . . . . . . . . . . 47

BURNERS/ORIFICES INSPECTION/SERVICING . . . . . 47

CHARGING THE UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . 48

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . 50

PREDATOR® FLASH CODES . . . . . . . . . . . . . . . . . . . . 50

COOLING TROUBLESHOOTING GUIDE. . . . . . . . . . . . 54

GAS HEAT TROUBLESHOOTING GUIDE. . . . . . . . . . . 57

2 Unitary Products Group

127408-YIM-B-0606

LIST OF FIGURES

Fig. # Pg. #

1 UNIT SHIPPING BRACKET . . . . . . . . . . . . . . . . . . . . . 8

2 CONDENSER COVERING . . . . . . . . . . . . . . . . . . . . . . 8

3 COMPRESSOR SECTION . . . . . . . . . . . . . . . . . . . . . . 8

4 PREDATOR® COMPONENT LOCATION . . . . . . . . . . 9

5 UNIT 4 POINT LOAD . . . . . . . . . . . . . . . . . . . . . . . . . 10

6 UNIT 6 POINT LOAD . . . . . . . . . . . . . . . . . . . . . . . . . 11

7 UNIT CENTER OF GRAVITY . . . . . . . . . . . . . . . . . . . 11

8 UNIT DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . 12

9 BOTTOM DUCT OPENINGS (FROM ABOVE). . . . . . 13

10 REAR DUCT DIMENSIONS . . . . . . . . . . . . . . . . . . . . 13

11 PREDATOR® ROOF CURB DIMENSIONS . . . . . . . . 14

12 SUNLINE™ TO PREDATOR® TRANSITION

ROOF CURBS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

13 SIDE PANELS WITH HOLE PLUGS. . . . . . . . . . . . . . 15

14 RETURN DOWNFLOW PLENUM WITH PANEL . . . . 15

15 DISCHARGE PANEL IN PLACE. . . . . . . . . . . . . . . . . 15

16 CONDENSATE DRAIN. . . . . . . . . . . . . . . . . . . . . . . . 15

17 ELECTRONIC THERMOSTAT FIELD WIRING . . . . . 17

Fig. #

18 FIELD WIRING 24 VOLT THERMOSTAT . . . . . . . . . 17

19 FIELD WIRING DISCONNECT - COOLING UNIT

WITH OR WITHOUT ELECTRIC HEAT. . . . . . . . . . . 18

20 FIELD WIRING DISCONNECT - COOLING UNIT

WITH GAS HEAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

21 SIDE ENTRY GAS PIPING. . . . . . . . . . . . . . . . . . . . . 21

22 BOTTOM ENTRY GAS PIPING . . . . . . . . . . . . . . . . . 21

23 ENTHALPY SET POINT CHART . . . . . . . . . . . . . . . . 25

24 HONEYWELL ECONOMIZER CONTROL W7212. . . 25

25 BELT ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . 26

26 DRY COIL DELTA P 50" CABINET . . . . . . . . . . . . . . 35

27 DRY COIL DELTA P 42" CABINET . . . . . . . . . . . . . . 35

28 TYPICAL FLAME . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

29 TYPICAL GAS VALVE . . . . . . . . . . . . . . . . . . . . . . . . 48

30 UNIT CONTROL BOARD. . . . . . . . . . . . . . . . . . . . . . 51

31 BASIC TROUBLESHOOTING FLOWCHART . . . . . . 52

32 POWER ON FLOW CHART. . . . . . . . . . . . . . . . . . . . 52

33 TRIP FAILURE FLOW CHART. . . . . . . . . . . . . . . . . . 53

Pg. #

Unitary Products Group 3

LIST OF TABLES

127408-YIM-B-0606

Tbl. # Pg. #

1 UNIT VOLTAGE LIMITATIONS . . . . . . . . . . . . . . . . . .10

2 UNIT TEMPERATURE LIMITATIONS. . . . . . . . . . . . .10

3 UNIT WEIGHT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

4 4 POINT LOAD WEIGHT. . . . . . . . . . . . . . . . . . . . . . .11

5 6 POINT LOAD WEIGHT. . . . . . . . . . . . . . . . . . . . . . .11

6 UNIT HEIGHT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

7 UNIT CLEARANCES . . . . . . . . . . . . . . . . . . . . . . . . . . 12

8 REAR DUCT DIMENSIONS. . . . . . . . . . . . . . . . . . . . . 13

9 CONTROL WIRE SIZES . . . . . . . . . . . . . . . . . . . . . . .16

10 ELECTRICAL DATA 7-1/2 TON. . . . . . . . . . . . . . . . . .19

11 ELECTRICAL DATA 10 TON. . . . . . . . . . . . . . . . . . . .19

12 ELECTRICAL DATA 12-1/2 TON. . . . . . . . . . . . . . . . .20

13 PHYSICAL DATA. . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

14 ELECTRIC HEAT MINIMUM SUPPLY AIR CFM. . . . .21

15 GAS APPLICATION DATA . . . . . . . . . . . . . . . . . . . . . 21

16 GAS PIPE SIZING - CAPACITY OF PIPE. . . . . . . . . .22

17 SUPPLY AIR LIMITATIONS. . . . . . . . . . . . . . . . . . . . .26

18 BLOWER PERFORMANCE 7-1/2 TON

STANDARD MOTOR - SIDE DUCT (IMPERIAL) . . . . 27

19 BLOWER PERFORMANCE 7-1/2 TON

STANDARD MOTOR - SIDE DUCT (METRIC) . . . . . . 27

20 BLOWER PERFORMANCE 7-1/2 TON

OPTIONAL MOTOR - SIDE DUCT (IMPERIAL). . . . . 27

21 BLOWER PERFORMANCE 7-1/2 TON

OPTIONAL MOTOR - SIDE DUCT (METRIC). . . . . . . 27

22 BLOWER PERFORMANCE 10 TON

STANDARD MOTOR - SIDE DUCT (IMPERIAL) . . . . 28

23 BLOWER PERFORMANCE 10 TON

STANDARD MOTOR - SIDE DUCT (METRIC) . . . . . . 28

24 BLOWER PERFORMANCE 10 TON

OPTIONAL MOTOR - SIDE DUCT (IMPERIAL). . . . . 28

25 BLOWER PERFORMANCE 10 TON

OPTIONAL MOTOR - SIDE DUCT (METRIC). . . . . . . 29

26 BLOWER PERFORMANCE 12-1/2 TON -

SIDE DUCT (IMPERIAL) . . . . . . . . . . . . . . . . . . . . . . .29

27 BLOWER PERFORMANCE 12-1/2 TON -

SIDE DUCT (METRIC). . . . . . . . . . . . . . . . . . . . . . . . .29

28 BLOWER PERFORMANCE 7-1/2 TON

STANDARD MOTOR - DOWNSHOT (IMPERIAL) . . . 30

Tbl. #
29 BLOWER PERFORMANCE 7-1/2 TON

STANDARD MOTOR - DOWNSHOT (METRIC) . . . . 30

30 BLOWER PERFORMANCE 7-1/2 TON

OPTIONAL MOTOR - DOWNSHOT (IMPERIAL) . . . . 30

31 BLOWER PERFORMANCE 7-1/2 TON

OPTIONAL MOTOR - DOWNSHOT (METRIC). . . . . . 31

32 BLOWER PERFORMANCE 10 TON

STANDARD MOTOR - DOWNSHOT (IMPERIAL) . . . 31

33 BLOWER PERFORMANCE 10 TON

STANDARD MOTOR - DOWNSHOT (METRIC) . . . . 31

34 BLOWER PERFORMANCE 10 TON

OPTIONAL MOTOR - DOWNSHOT (IMPERIAL) . . . . 32

35 BLOWER PERFORMANCE 10 TON

OPTIONAL MOTOR - DOWNSHOT (METRIC). . . . . . 32

36 BLOWER PERFORMANCE 12-1/2 TON -

DOWNSHOT (IMPERIAL) . . . . . . . . . . . . . . . . . . . . . . 33

37 BLOWER PERFORMANCE 12-1/2 TON -

DOWNSHOT (METRIC) . . . . . . . . . . . . . . . . . . . . . . . 33

38 INDOOR BLOWER SPECIFICATIONS. . . . . . . . . . . . 33

39 ADDITIONAL STATIC RESISTANCE 50” CABINET

(IMPERIAL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

40 ADDITIONAL STATIC RESISTANCE 42” CABINET

(IMPERIAL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

41 ADDITIONAL STATIC RESISTANCE 50” CABINET

(METRIC). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

42 ADDITIONAL STATIC RESISTANCE 42” CABINET

(METRIC). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

43 MOTOR SHEAVE DATUM . . . . . . . . . . . . . . . . . . . . . 39

44 ELECTRIC HEAT LIMIT SETTING . . . . . . . . . . . . . . . 42

45 ELECTRIC HEAT ANTICIPATOR SETPOINTS . . . . . 42

46 GAS HEAT LIMIT SETTINGS . . . . . . . . . . . . . . . . . . . 44

47 GAS HEAT ANTICIPATOR SETPOINTS . . . . . . . . . . 44

48 GAS HEAT STAGES. . . . . . . . . . . . . . . . . . . . . . . . . . 46

49 GAS RATE CUBIC FEET PER HOUR . . . . . . . . . . . . 47

50 7.5 TON SUPERHEAT CHARGING . . . . . . . . . . . . . . 48

51 10 TON SUPERHEAT CHARGING. . . . . . . . . . . . . . . 49

52 UNIT CONTROL BOARD FLASH CODES . . . . . . . . . 50

53 IGNITION CONTROL FLASH CODES . . . . . . . . . . . . 51

Pg. #

4 Unitary Products Group

127408-YIM-B-0606

GENERAL

YORK® Predator® units are single package air conditioners
with optional gas heating designed for outdoor installation on
a rooftop or slab and for non-residential use. These units can
be equipped with factory or field installed electric heaters for
heating applications.

These units are completely assembled on rigid, permanently
attached base rails. All piping, refrigerant charge, and electri­cal wiring is factory installed and tested. The units require
electric power, gas supply (where applicable), and duct con­nections. The electric heaters have nickel-chrome elements
and utilize single-point power connection.

SAFETY CONSIDERATIONS

If the information in this manual is not followed
exactly, a fire or explosion may result causing prop­erty damage, personal injury or loss of life.

Do not store or use gasoline or other flammable
vapors and liquids in the vicinity of this or any other
appliance.

WHAT TO DO IF YOU SMELL GAS:

a. Do not try to light any appliance.
b. Do not touch any electrical switch; do not use

any phone in your building.

c. Immediately call your gas supplier from a neigh-

bor’s phone. Follow the gas supplier’s instruc­tions.

Should overheating occur, or the gas supply fail to
shut off, shut off the manual gas valve to the furnace
before shutting off the electrical supply.

Do not use this furnace if any part has been under
water. Immediately call a qualified service technician
to inspect the furnace and to replace any part of the
control system and any gas control which has been
under water.

Due to system pressure, moving parts, and electrical compo­nents, installation and servicing of air conditioning equipment
can be hazardous. Only qualified, trained service personnel
should install, repair, or service this equipment. Untrained
personnel can perform basic maintenance functions of clean­ing coils and filters and replacing filters.

Observe all precautions in the literature, labels, and tags
accompanying the equipment whenever working on air condi­tioning equipment. Be sure to follow all other applicable
safety precautions and codes including ANSI Z223.1 or CSA­B149.1- latest edition.

Wear safety glasses and work gloves. Use quenching cloth
and have a fire extinguisher available during brazing opera­tions.

d. If you cannot reach your gas supplier, call the fire

department.

Installation and service must be performed by a
qualified installer, service agency or the gas sup­plier.

INSPECTION

As soon as a unit is received, it should be inspected for possi­ble damage during transit. If damage i s evident , the extent of
the damage should be noted on the carrier’s freight bill. A
separate request for inspection by the carrier’s agent should
be made in writing.

This furnace is not to be used for temporary heating
of buildings or structures under construction.

Before performing service or maintenance opera­tions on unit, turn off main power switch to unit. Elec­trical shock could cause personal injury. Improper
installation, adjustment, alteration, service or main­tenance can cause injury or property damage. Refer
to this manual. For assistance or additional informa­tion consult a qualified installer, service agency or
the gas supplier.

Unitary Products Group 5

127408-YIM-B-0606

REFERENCE

Additional information is available in the following reference
forms:

• Technical Guide - DM090-150, 259335

• General Installation - DM090 - 150, 127408

• Pre-start & Post-start Check List

• Economizer Accessory ­Downflow Factory Installed
Downflow Field Installed
Horizontal Field Installed

• Motorized Outdoor Air Damper

• Manual Outdoor Air Damper (0-100%)

• Manual Outdoor Air Damper (0-35%)

• Gas Heat Propane Conversion Kit

• Gas Heat High Altitude Kit (Natural Gas)

• Gas Heat High Altitude Kit (Propane)

• –60°F Gas Heat Kit

• Electric Heater Accessory

APPROVALS

Design certified by CSA as follows:

1. For use as a cooling only unit, cooling unit with supple­mental electric heat or a forced air furnace.

2. For outdoor installation only.

3. For installation on combustible material and may be
installed directly on combustible flooring or, in the U.S.,
on wood flooring or Class A, Class B or Class C roof cov­ering materials.

4. For use with natural gas (convertible to LP with kit).

This product must be installed in strict compliance
with the enclosed installation instructions and any
applicable local, state, and national codes including,
but not limited to, building, electrical, and mechanical
codes.

RENEWAL PARTS

Contact your local York® parts distribution center for autho­rized replacement parts.

Incorrect installation may create a condition where the
operation of the product could cause personal in jury
or property damage.

The installer should pay particular attention to the words:
NOTE, CAUTION, and WARNING. N OTES are intended to
clarify or make the installation easier. CAUTIONS are given
to prevent equipment damage. WARNINGS are given to alert
installer that personal injury and/or equipment damage may
result if installation procedure is not handled properly.

6 Unitary Products Group

127408-YIM-B-0606

NOMENCLATURE

D M 090 N10 A 7 A AA 3 0 1 2 4 A

7.5-12.5 Ton York® Model Number Nomenclature

Product Category

D = A/C, Single Pkg., R-22

Product Identifier

M = 9.0 EER A/C

Nominal Cooling Capacity

090 = 7.5 Ton
120 = 10.0 Ton
150 = 12.5 Ton

Heat Type and Nominal Heat Capacity

C00 = Cooling Only. No heat installed

Gas Heat Options

N10 = 100 MBH Output Aluminized Steel
N15 = 150 MBH Output Aluminized Steel
S10 = 100 MBH Output Stainless Steel
S15 = 150 MBH Output Stainless Steel

Electric Heat Options

E09 = 9 KW
E18 = 18 KW
E24 = 24 KW
E36 = 36 KW
E54 = 54 KW

Airflow

A = Std. Motor
B = Std. Motor/Econo./Barometric Relief (Downflow

Only)
C = Std. Motor/Econo./Power Exhaust (Downflow Only)
D = Std. Motor/Motorized Damper (Downflow Only)
E = Std. Motor/Horizontal Economizer (No Baro.)
F = Std. Motor/Slab Econo./Power Exhaust

(Downflow Only)
G = Std. Motor/Slab Econo./Barometric Relief

(Downflow Only)
N=HiStaticMtr.
P = Hi Static Mtr./Econo./Barometric Relief

(Downflow Only)
Q = Hi Static Mtr./Econo./Power Exhaust

(Downflow Only)
R = Hi Static Mtr./Motorized Damper (Downflow Only)
S = Hi Static Mtr./Horizontal Economizer (No Baro.)
T = Hi Static Mtr./Slab Econo./Power Exhaust

(Downflow Only)
U = Hi Static Mtr./Slab Econo./Barometric Relief

(Downflow only)

Voltage

7 = 380/415-3-50

Product Style

A = Style A
B = Style B
C = Style C

These four digits will not be assigned until a quote is requested, or an order placed.

SS Drain Pan

Honeywell Controller, DFS, APS

Simplicity IntelliComfort Controller

Simplicity IntelliComfort Controller w/ModLinc

2" Pleated filters

BAS Ready Unit with Belimo Economizer

Shipping Bag

Any Combination of Additional Options that Don’t Have an Option Code Pre-assigned

Product Generation

3 = Third Generation
4 = Fourth Generation

AA = None
AB = Phase Monitor
AC = Coil Guard
AD = Dirty Filter Switch
AE = Phase Monitor & Coil Guard
AF = Phase Monitor & Dirty Filter Switch
AG = Coil Guard & Dirty Filter Switch
AH = Phase Monitor, Coil Guard & Dirty Filter Switch

ZZ = If desired option combination is not listed above, ZZ will be assigned and configuration options will be

located in digits 15-18.

Installation Options

A = No Options Installed
B=Option1
C=Option2
D = Options 1 & 2
E=Option3
F = Option 4
G = Options 1 & 3
H = Options 1 & 4
J=Options1,2&3
K = Options 1, 2, & 4
L = Options 1,3 & 4
M=Options1,2,3,&4
N = Options 2 & 3
P = Options 2 & 4
Q = Options 2, 3, & 4
R = Options 3 & 4
S=Option5
T = Options 1 & 5
U = Options 1, 3, & 5
V = Options 1, 4, & 5
W = Options 1, 3, 4, & 5
X = Options 3 & 5
Y = Options 4 & 5
Z = Options 3, 4 & 5

Configuration Options (not required for all units)

Additional Options

RC = Coil Guard, Shipping Bag & American Flag
TA = Technicoat Condenser Coil
TJ = Technicoat Evaporator Coil
TS = Technicoat Evaporator & Condenser Coils

Options

1 = Disconnect
2 = Non-Pwr'd Conv. Outlet
3 = Smoke Detector S.A.
4 = Smoke Detector R.A.
5=Pwr'dConv.Outlet

Unitary Products Group 7

INSTALLATION

INSTALLATION SAFETY INFORMATION

127408-YIM-B-0606

Read these instructions before continuing this appliance
installation. This is an outdoor combination heating and cool­ing unit. The installer must assure that these instructions are
made available to the consumer and with instructions to
retain them for future reference.

1. Refer to the furnace rating plate for the approved type of
gas for this furnace.

2. Install this furnace only in a location and position as
specified on Page 10 of these instructions.

3. Never test for gas leaks with an open flame. Use com­mercially available soap solution made specifically for
the detection of leaks when checking all connections, as
specified on Pages 8, 22, 23 and 45 of these instruc­tions.

4. Always install furnace to operate within the furnace's
intended temperature-rise range with the duct system
and within the allowable external static pressure range,
as specified on the unit name/rating plate, specified on
Page 47 of these instructions.

5. This equipment is not to be used for tempora ry heating
of buildings or structures under construction.

Bracket
Screws

Turn down

FIGURE 1 - UNIT SHIPPING BRACKET

4. Remove the toolless doorknobs and instruction packet
prior to installation.

Condenser
Coil External
Protective
Covering

Barometric
Relief Hood in
Shipping Loca­tion (if included)

FIGURE 2 - CONDENSER COVERING

FIRE OR EXPLOSION HAZARD
Failure to follow the safety warning exactly could

result in serious injury, death or property damage.
Never test for gas leaks with an open flame. Use a

commercially available soap solution made specifi­cally for the detection of leaks to check a ll connec­tions. A fire or explosion may result causing property
damage, personal injury or loss of life.

PRECEDING INSTALLATION

1. Remove the two screws holding the brackets in the front,
rear and compressor side fork-lift slots.

2. Turn each bracket toward the ground and the protective
plywood covering will drop to the ground.

3. Remove the condenser coil external protective covering
prior to operation.

Toolless
Doorknobs

Installation
Instruction
Packet

FIGURE 3 - COMPRESSOR SECTION

8 Unitary Products Group

127408-YIM-B-0606

This product must be installed in strict compliance
with the enclosed installation instructions and any
applicable local, state and national codes including,
but not limited to, building, electrical, and mechani­cal codes.

The furnace and its individual shut-off valve must be
disconnected from the gas supply piping system
during any pressure testing at pressures in excess
of 1/2 PSIG.

Pressures greater than 1/2 PSIG will cause gas
valve damage resulting in a hazardous condition. If it
is subjected to a pressure greater than 1/2 PSIG, the
gas valve must be replaced.

The furnace must be isolated from the gas supply
piping system by closing its individual manual shut­off valve during any pressure testing of the gas sup­ply piping system at test pressures equal to or less
than 1/2 PSIG.

LIMITATIONS

These units must be installed in accordance with the follow­ing:

1. Local building codes, and

2. Local gas utility requirements

3. Local plumbing and waste water codes, and

4. Other applicable local codes.
Refer to Tables 1 & 2 for unit application data.
After installation, gas fired units must be adjusted to obtain a

temperature rise within the range specified on the unit rating
plate.

If components are to be added to a unit to meet local codes,
they are to be installed at the dealer’s and/or customer’s
expense.

Size of unit for proposed installation should be based on heat
loss/heat gain calculation made according to the metho ds of
Air Conditioning Contractors of America (ACCA).

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FIGURE 4 - PREDATOR® COMPONENT LOCATION

This furnace is not to be used for temporary heating of build­ings or structures under construction.

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Unitary Products Group 9

127408-YIM-B-0606

TABLE 1: UNIT VOLTAGE LIMITATIONS

Power Rating

380/415-3-50 342 456

*.

Utilization range “A” in accordance with ARI Standard

110.

TABLE 2: UNIT TEMPERATURE LIMITATIONS

Wet Bulb T emperature °F(°C) of Air

Dry Bulb Temperature °F(°C) of Air

*

Temperature Min. Max.

on Evaporator Coil

on Condenser Coil

Minimum Maximum

57(14) 72(22)

0(-18) 125(52)

LOCATION

Use the following guidelines to select a suitable location for
these units:

1. Unit is designed for outdoor installation only.

2. Condenser coils must have an unlimited supply of air.
Where a choice of location is possible, position the unit
on either north or east side of building.

3. Suitable for mounting on roof curb.

4. For ground level installation, use a level concrete slab
with a minimum thickness of 4 inches (102 mm). The
length and width should be at least 6 inches (152 mm)
greater than the unit base rails. Do not tie slab to the
building foundation.

5. Roof structures must be able to support the weight of the
unit and its options/accessories. Unit must be installed on
a solid, level roof curb or appropriate angle iron frame.

6. Maintain level tolerance to 1/2” (13 mm) across the entire
width and length of unit.

RIGGING AND HANDLING

Exercise care when moving the unit. Do not remove any
packaging until the unit is near the place of installation. Rig
the unit by attaching chain or cable slings to the lifting holes
provided in the base rails. Spreader bars, whose length
exceeds the largest dimension across the unit, MUST be
used across the top of the unit.

If a unit is to be installed on a roof curb other than a
YORK roof curb, gasketing must be applied to all sur­faces that come in contact with the unit underside.

Before lifting, make sure the unit weight is distrib­uted equally on the rigging cables so it will lift evenly.

Units may be moved or lifted with a forklift. Slotted openings
in the base rails are provided for this purpose.

LENGTH OF FORKS MUST BE A MINIMUM OF 60 INCHES
(1524 mm.).

All panels must be secured in place when the unit is
lifted.

The condenser coils should be protected from rig­ging cable damage with plywood or other suitable
material.

Excessive exposure of this furnace to contaminated
combustion air may result in equipment damage or
personal injury. Typical contaminates include: per­manent wave solution, chlorinated waxes and clean­ers, chlorine based swimming pool chemicals, water
softening chemicals, carbon tetrachloride, Halogen
type refrigerants, cleaning solvents (e.g. perchloro­ethylene), printing inks, paint removers, varnishes,
hydrochloric acid, cements and glues, antistatic fab­ric softeners for clothes dryers, masonry acid wash-

L E F T

A

D

FIGURE 5 - UNIT 4 POINT LOAD

F R O N T

CB

ing materials.

10 Unitary Products Group

127408-YIM-B-0606

TABLE 3: UNIT WEIGHT

Model

090
120
150

Shipping Weight

lbs. (kg)

865 (392.4) 860 (390.1)
1143 (518.6) 1138 (516.3)
1202 (545.3) 1197 (543.1)

TABLE 4: 4 POINT LOAD WEIGHT

Model

090
120
150

ABCD

192

(87.1)

245

(111)

262

(118)

Location (lbs. (kg.))

143

(64.9)

209
(94)

224

(101)

TABLE 5: 6 POINT LOAD WEIGHT

Model

090
120
150

ABCDEF

135

(61.2)

168

(76.2)

180

(81.6)

L E F T

A

Locations (lbs. (kg.))

110

(49.9)91(41.3)

151

(68.4)

161
(73)

136

(61.7)

145

(65.8)

C

B

F

(64.4)

(89.8)

(96.2)

E

FIGURE 6 - UNIT 6 POINT LOAD

X

LEFT

Y

FRONT

Operating Weight

lbs. (kg)

224

(101.6)

305

(138)

327

(148)

142

198

212

F R O N T

(136.5)

(162)

(173)

172

(78.0)

219

(99.3)

235

(107)

D

301

357

382

(95.71)

(110.7)

(118.8)

211

244

262

CLEARANCES

All units require particular clearances for proper operation and
service. Installer must make provisions for adequate combus­tion and ventilation air in accordance with section 5.3 of Air for
Combustion and Ventilation of the National Fuel Gas Code,
ANSI Z223.1 – Latest Edition (in U.S.A.), or Sections 7.2, 7.3,
or 7.4 of Gas Installation Codes, CSA-B149.1 (in Canada) ­Latest Edition, and/or applicable provisions of the local building
codes. Refer to Table 7 for clearances required for combustible
construction, servicing, and proper unit operation.

Do not permit overhanging structures or shrubs to
obstruct condenser air discharge outlet, combustion
air inlet or vent outlets.

Excessive exposure to contaminated combustion air
will result in safety and performance related prob­lems. To maintain combustion air quality, the recom­mended source of combustion air is the outdoor air
supply. The outdoor air supplied for combustion
should be free from contaminants due to chemical
exposure that may be present from the following
sources.

• Commercial buildings

• Indoor pools

• Laundry rooms

• Hobby or craft rooms

• Chemical storage areas
The following substances should be avoided to

maintain outdoor combustion air quality.

• Permanent wave solutions

• Chlorinated waxes and cleaners

• Chlorine based swimming pool cleaners

• Water softening chemicals

• De-icing salts or chemicals

• Carbon tetrachloride

• Halogen type refrigerants

• Cleaning solvents (such as perchloroethylene)

• Printing inks, paint removers, varnishes, etc.

• Hydrochloric acid

• Cements and glues

• Anti-static fabric softeners for clothes dryers

• Masonry acid washing materials

Unit Model Number X Y

DM090 38 (965.2) 23 (584.2)
DM120 47 1/2 (1206.5) 25 1/2 (647.7)
DM150 47 1/2 (1206.5) 25 1/2 (647.7)

FIGURE 7 - UNIT CENTER OF GRAVITY

Unitary Products Group 11

127408-YIM-B-0606

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FIGURE 8 - UNIT DIMENSIONS
TABLE 6: UNIT HEIGHT

Unit Model Number X

DM090
DM120
DM150

DETAIL B

G a s P i p e I n l e t

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42 (1067)
50 3/4 (1289)
50 3/4 (1289)

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NOTE: A one-inch clearance must be provided between

any combustible material and the supply du ctwork
for a distance of 3 feet from the unit.

DETAIL C

3 - 3 / 4

( 9 5 )

2 - 3 / 8

( 6 0 )

5 - 1 / 4
( 1 3 5 )

1 7 - 1 3 / 1 6

( 4 5 0 )

V i e w o f W a l l A c r o s s f r o m C o i l

TABLE 7: UNIT CLEARANCES

†

Top

Front

‡

Rear

*.

In inches and millimeters, in.(mm).

†.

Units must be installed outdoors. Overhanging struc-

72(1830)

36(915)
36(915)

*

Right

Left

Bottom

ture or shrubs should not obstruct condenser air dis­charge outlet.

‡.

To remove the slide-out drain pan, a rear clearance of
60” (1525 mm) is required. If space is unavailable, the
drain pan can be removed through the front by separat­ing the corner wall.

**.

Units may be installed on combustible floors.

B a s e
P a n

3 - 9 / 1 6

( 9 0 )

DETAIL D

5 - 3 / 8

12(305)
36(915)

**

0(0)

NOTE: If the unit includes gas heating, locate the unit so

the flue exhaust is at least:

• Three (3) feet above any forced air inlet located within 10
horizontal feet (excluding those integral to the unit).

• Four (4) feet below, four (4) horizontal feet from, or one
(1) foot above any door or gravity air inlet into the build­ing.

• Four (4) feet from electric meters, gas meters, regula­tors, and relief equipment.

( 1 3 5 )

12 Unitary Products Group

127408-YIM-B-0606

2

(

)

.

6 - 1 3 / 1 6

( 1 7 5 )

L E F T

1 9 - 3 / 1 6

( 4 8 5 )

1 - 3 / 1 6

1 7 - 3 / 1 6

( 5 4 0 )

( 4 3 5 )

1 4 - 2 3 / 3 2

( 3 7 5 )

1 6 - 3 / 8

( 4 1 5 )

1 8 - 1 / 1 6

( 4 6 0 )

6 - 1 3 / 1 6

( 1 7 5 )

3 2 - 1 1 / 1 6

( 8 3 0 )

1 8

( 4 5 5 )

2 7 - 1 / 2

( 7 0 0 )

B o t t o m P o w e r ,
C o n t r o l a n d
C o n v e n i e n c e
O u t l e t W i r i n g
E n t r y

6 3 - 1 / 2

1 6 1 0

( 5 3 5 )

2 1

F R O N T

FIGURE 9 - BOTTOM DUCT OPENINGS (FROM ABOVE)

( 6 1 0 )

( X X X ) I N D I C A T E S

N O T E :

6 - 1 3 / 1 6

( 1 7 5 )

2 4

D I M E N S I O N S I N
M I L L I M E T E R S

B o t t o m g a s
s u p p l y e n t r y

1 2 - 5 / 1 6

( 3 1 5 )

Supply

Air

18-1/4

(465)

5-5/32

(130)

C

NOTE: (XXX) indicates millimeters

FIGURE 10 - REAR DUCT DIMENSIONS

TABLE 8: REAR DUCT DIMENSIONS

Cabinet Size

“A” “B” “C”

50 3/4 (1289) 28 1/4 (717) 18 1/16 (459) 28 1/4 (717

42 (1067) 27 3/4 (705) 12 1/16 (308) 27 1/2 (699)

Dimensions

DOT PLUGS

Return

18-1/4

(465)

A

Air

B

2-31/32

(75)

31-11/16

(805)

Unitary Products Group 13

127408-YIM-B-0606

)

DUCTWORK

Ductwork should be designed and sized according to the
methods in Manual D of the Air Conditioning Contractors of
America (ACCA) or as recommended by any other recog­nized authority such as ASHRAE or SMACNA.

A closed return duct system should be used. This will not
preclude use of economizers or outdoor fresh air intake. The
supply and return air duct connections a t the unit should be
made with flexible joints to minimize noise.

The supply and return air duct systems should be designed
for the CFM and static pressure requirements of the job. They
should NOT be sized to match the dimensions of the duct
connections on the unit.

Refer to Figure 9 for bottom air duct openings. Refer to Fig­ure 10 for rear air duct openings.

8 0 - 5 / 8
( 2 0 5 0 )

2 0

( 5 1 0 )

6

2 0

( 1 5 0 )

( 5 1 0 )

DUCT COVERS

Units are shipped with the side duct openings covered and a
covering over the bottom of the unit. For bottom duct applica­tion, no duct cover changes are necessary. For side duct
application, remove the side duct covers and install over the
bottom duct openings. The panels removed from the side
duct connections are designed to be reused by securing each
panel to its respective downflow opening. But keep in mind
that the supply panel is installed with the painted surface UP,
facing the heat exchanger, while the return panel is installed
with the painted surface DOWN, facing the downflow duct
opening. The supply panel is secured with the bracket
(already in place from the factory) and two screws. It’s a snug
fit for the panel when sliding it between the heat e xchanger
and unit bottom, but there is room. The return panel is
secured with four screws.

R I G H T

S U P P L Y

I N S U L A T E D D E C K U N D E R

C O N D E N S E R S E C T I

O N

2 T Y P .
( 5 0 )

3 0

( 7 6 0 )

5 0 - 1 / 2
( 1 2 8 5 )

N O T E :

R E T U R N

( X X X ) I N D I C A T E S
D I M E N S I O N S I N
M I L L I M E T E R S

( 2 0 5 )

FIGURE 11 - PREDATOR® ROOF CURB DIMENSIONS

3 0 - 1 / 2

F R O N T

5 0 - 1 / 2
( 1 2 8 5 )

7 6 - 5 / 8
( 1 9 4 5 )

9 4

( 2 3 9 0 )

( 7 7 5 )

R E T U R N

8

2 T Y P

( 5 0 )

I N S U L A T E D D E C K U N D E R

C O M P R E S S O R S E C T I O N

1 4

O R

( 3 5 5 )

2 3

( 5 8 5 )

S U P P L Y

F R O N T

( 1 0 0 )

( 6 6 0 )

2 6

4

6 4 - 1 / 4
( 1 6 3 0 )

5 9 - 1 / 4
( 1 5 0 5 )

8 0 - 5 / 8

( 2 0 5 0 )

R I G H T

1 0

( 2 5 5

FIGURE 12 - SUNLINE™ TO PREDATOR

®

TRANSITION ROOF CURBS

14 Unitary Products Group

127408-YIM-B-0606

When fastening ductwork to side duct flanges on
unit, insert screws through duct flanges only. DO
NOT insert screws through casing. Outdoor duct­work must be insulated and water-proofed.

FIGURE 13 - SIDE PANELS WITH HOLE PLUGS

Note orientation. Panel is “insulation” side up.

CONDENSATE DRAIN

The side condensate drain is reversible and maybe re-ori­ented to the rear of the cabinet to facilitate condensate pip­ing. A condensate drain connection is available through the
base pan for piping inside the roof curb. Trap the connection
per Figure 16: Condensate Drain. The trap and drain lines
should be protected from freezing.

Plumbing must conform to local codes. Use a sealing com­pound on male pipe threads. Install condensate drain line
from the 3/4 inch (19 mm) NPT female connection on the unit
to an open drain.

3 " M i n i m u m

( 7 6 . 2 m m )

FIGURE 14 - RETURN DOWNFLOW PLENUM WITH

PANEL

FIGURE 16 - CONDENSATE DRAIN

COMPRESSORS

The compressors are mounted on elastomer insulators. The
mounting bolts have been fully tightened for shipping.

Do not loosen the compressor mounting bolts.

FILTERS

Two-inch filters are supplied with each unit. One-inch filters
may be used with no modification to the filter racks. Filters
must always be installed ahead of evaporator coil and must
be kept clean or replaced with same size and type. Dirty fil­ters reduce the capacity of the unit and result in frosted coils
or safety shutdown. All units use four (4) 20”x25”x2” filters.
The unit should not be operated without filters properly
installed.

Make sure that panel latches are properly positioned
on the unit to maintain an airtight seal.

FIGURE 15 - DISCHARGE PANEL IN PLACE

Unitary Products Group 15

THERMOSTAT WIRING

The thermostat should be located on an inside wall approxi­mately 56 inches (1422 mm) above the floor where it will not
be subject to drafts, sun exposure or heat from electrical fix­tures or appliances. Follow the manufacturer's instructions
enclosed with thermostat for general installation procedure.
Seven (7) color-coded, insulated wires should be used to
connect the thermostat to the unit. Refer to Table 9 for control
wire sizing and maximum length.

127408-YIM-B-0606

Avoid damage to internal components if drilling
holes for disconnect mounting.

NOTE: Since not all local codes allow the mounting of a dis-

connect on the unit, please confirm compliance with
local code before mounting a disconnect on the unit.

TABLE 9: CONTROL WIRE SIZES

Wire Size Maximum Length

18 AWG

150 Feet (45.72 meters)

POWER AND CONTROL WIRING

Field wiring to the unit, fuses, and disconnects must conform
to provisions of National Electrical Code (NEC), ANSI/NFPA
No. 70 – Latest Edition (in U.S.A.), current Canadian Electri­cal Code C221, and/or local ordinances. The unit must be
electrically grounded in accordance with NEC and CEC as
specified above and/or local codes.

Voltage tolerances which must be maintained at the com­pressor terminals during starting and running conditions are
indicated on the unit Rating Plate and Table 1.

The internal wiring harnesses furnished with thi s unit are an
integral part of the design certified unit. Field alteration to
comply with electrical codes should not be required. If any of
the wire supplied with th e un it must be re pla ce d, rep lac em en t
wire must be of the type shown on the wiring diagram and the
same minimum gauge as the replaced wire.

A disconnect must be utilized for these units. When installing
a disconnect, refer to Figure 4 for the recommended mount­ing location.

Electrical line must be sized properly to carry the load. USE
COPPER CONDUCTORS ONLY. Each unit must be wired
with a separate branch circuit fed directly from the meter
panel and properly fused.

Refer to Figures 17, 18 and 19 for typical field wiring and to
the appropriate unit wiring diagram mounted inside control
doors for control circuit and power wiring information.

When connecting electrical power and control wiring
to the unit, water-proof connectors must be used so
that water or moisture cannot be drawn into the unit
during normal operation. The above water-proofing
conditions will also apply when installing a field sup­plied disconnect switch.

POWER WIRING DETAIL

Units are factory wired for the voltage shown on the unit
nameplate. Refer to Electrical Data Tables 10 through 12 size
power wiring, fuses, and disconnect switch.

Power wiring is brought into the unit through the side of the
unit or the basepan inside the curb.

16 Unitary Products Group

127408-YIM-B-0606

2

T H E R M O S T A T

T E R M I N A L S

R C

R H

Y 1

Y 2

W 1

W 2

X 1

X 3

X 4

A 1

A 2

1

E l e c t r o n i c p r o g r a m m a b l e T h e r m o s t a t 2 E T 0 7 7 0 0 1 0 0 2 4 ( i n c l u d e s s u b b a s e ) .
T e r m i n a l s A 1 a n d A 2 p r o v i d e a r e l a y o u t p u t t o c l o s e t h e o u t d o o r

e c o n o m i z e r d a m p e r s w h e n t h e t h e r m o s

1

G

C

T

T

T O R E M O T E S E N S O R
2 E T 0 4 7 0 1 3 2 4 I F U S E D

2

t a t s w i t c h e s t o t h e s e t - b a c k p o s i t i o n .

FIGURE 17 - ELECTRONIC THERMOSTAT FIELD WIRING

U N I T T E R M I N A L S

S T R I P T B 1

R

Y 1

Y 2

W 1

W 2

G

C

X

O C C

2 4 V o l t
T r a n s f o r m e r

T - S T A T

W 1

W 2

Y 1

G

Y 2

C

R H

R C

W 1

W 2

Y 1

G

O C C

M I N P O S

Y 2

X

R

S D

C

FIGURE 18 - FIELD WIRING 24 VOLT THERMOSTAT

R E M O T E

U N I T C O N T R O L

B O A R D

Unitary Products Group 17

GROUND

LUG

127408-YIM-B-0606

TERMINAL BLOCK TB1

FIELD SUPPLIED

DISCONNECT

THREE

PHASE

POWER

SUPPLY

FIGURE 19 - FIELD WIRING DISCONNECT - COOLING UNIT WITH OR WITHOUT ELECTRIC HEAT

CONTACTOR 1M

T1

T2

T3

L1

L2

L3

FIELD SUPPLIED

GROUND

DISCONNECT

LUG

THREE
PHASE

POWER

SUPPLY

FIGURE 20 - FIELD WIRING DISCONNECT - COOLING UNIT WITH GAS HEAT

18 Unitary Products Group

127408-YIM-B-0606

TABLE 10: ELECTRICAL DATA 7-1/2 TON

ea.

Supply
Blower

Motor FLA

3 HP FLA 3 HP 2 HP 3 HP 2 HP

CompressorsODFan

*

Voltage

RLA

ea.

380

8.3 62 1.1 4.9 2.2 None - - 26.1 28.3 30 35

415

8.3 62 1.1 4.9 2.2 None - - 26.1 28.3 30 35

*.

Unit voltage limitations: minimum utilization 342 volts, maximum utilization 457 volts.

†.

Maximum HACR breaker of the same amp size is acceptable.

LRA

ea.

Motors

FLA

Pwr Exh

Motor

Electric

Heater

Model No.

ActualkWHeater

Amps

TABLE 11: ELECTRICAL DATA 10 TON

CompressorsODFan

*

Voltage

RLA

LRA

ea.

ea.

380 9.6

415 9.6 80 1.1 5.2 7.5 2.2

*.

Unit voltage limitations: minimum utilization 342 volts, maximum utilization 457 volts.

†.

Maximum HACR breaker of the same amp size is acceptable.

80 1.1 5.2 7.5 2.2

Motors

FLA

ea.

Supply Blower

Motor FLA

2 HP

(1.5 kW)

4 HP

(3 kW)

Pwr Exh

Motor

FLA

Electric

Heater

Model No.

None - - 29.0 31.3 31.2 33.5 35 40 40 40

2TP04521850 11.3 17.2 29.0 31.3 31.2 33.5 35 40 40 40

2TP04522450 15.0 22.8 35.0 37.9 37.7 40.6 35 40 40 45
2TP04523650 21.3 32.4 47.0 49.8 49.7 52.6 50 50 50 60
2TP04525450 33.8 51.4 70.7 73.6 73.4 76.3 80 80 80 80

None - - 29.0 31.3 31.2 33.5 35 40 40 40
2TP04521850 13.5 18.8 30.0 32.9 32.7 35.6 35 40 40 40
2TP04522450 17.9 24.9 37.6 40.5 40.4 43.3 40 45 45 45
2TP04523650 25.4 35.3 50.7 53.5 53.4 56.3 60 60 60 60
2TP04525450 40.4 56.2 76.8 79.6 79.5 82.4 80 80 80 90

ActualkWHeater

Amps

Min. Circuit

Ampacity

(Amps)

Min. Circuit

Ampacity

(Amps)

2 HP

(1.5 kW)

4 HP

(3 kW)

w/Power
Exhaust

(Amps)

w/Power
Exhaust

(Amps)

2 HP

(1.5
kW)

MCA

MCA

4 HP

(3 kW)

Max Fuse

Size (Amps)

Max Fuse

Size (Amps)

2 HP

(1.5 kW)

†

†

4 HP

(3 kW)

Max Fuse Size

w/Power
Exhaust

(Amps)

Max Fuse Size

w/Power
Exhaust

(Amps)

2 HP

4 HP

(1.5

(3

kW)

kW)

Unitary Products Group 19

TABLE 12: ELECTRICAL DATA 12-1/2 TON

Compressors

*

Voltage

RLA

380 12.0 91 1.1 7.5 2.2

415 12.0 101 1.1 7.5 2.2

*.

Unit voltage limitations: minimum utilization 342 volts, maximum utilization 457 volts.

†.

Maximum HACR breaker of the same amp size is acceptable.

ea.

LRA

ea.

OD
Fan

Motors

FLA

ea.

Supply Air

Blower

Motor FLA

4 HP (3 kW) FLA

Pwr Exh

Motor

Electric

Heater

Model No.

None - - 36.7 38.9 45 50
2TP04521850 11.3 17.2 36.7 38.9 45 50
2TP04522450 15.0 22.8 37.9 40.6 45 50
2TP04523650 21.3 32.4 49.8 52.6 50 60
2TP04525450 33.8 51.4 73.6 76.3 80 80

None - - 36.7 38.9 45 50
2TP04521850 13.5 18.8 36.7 38.9 45 50
2TP04522450 17.9 24.9 40.5 43.3 45 50
2TP04523650 25.4 35.3 53.5 56.3 60 60
2TP04525450 40.4 56.2 79.6 82.4 80 90

TABLE 13: PHYSICAL DATA

Component

Blower, Centrifugal

Evaporator

Blower

Evaporator

Coil

Condenser

Fan

(2 per Unit)

Condenser

Coil

(2 per unit)

Refrigerant

Charge

Compressors

Air Filters

Dia. X Wd. in.

(Dia. X Wd. mm.)

Motor, Standard - HP (kW) 3 (2.2) 2 (1.5) 4 (3)

Motor, Optional - HP (kW) 3 (2.2) 4 (3) N/A

Rows 2 3 4

Fins per 2.54 cm (1 in.) 15 15 15

Height - in. (mm.) 32 (810) 40 (1020) 40 (1020)

2

Face Area - ft.

(m2)

Propeller Dia. - in. (mm.) ea. 24 (610) 24 (610) 24 (610)

Motor - HP (kW) ea. 3/4 (0.56) 3/4 (0.56) 3/4 (0.56)

Airflow - CFM (m

3

/s) ea.

Rows (each) 1 1 2

Fins per inch (2.54 mm) 20 20 20

Height - in. (mm.) 28 (711) 44 (1120) 44 (1120)

Face Area - ft.

2

(m2)
System 1 - lbs. (kg.) 4.75 (2.15) 6.0 (2.72) 11.0 (4.99)
System 2 - lbs. (kg.) 4.0 (1.81) 5.75 (2.61) 10.0 (4.54)

Quantity 2 2 2

Type Recip Recip Scroll
Size

Wd. x Ht. x Thickness in.

(Wd. x Ht. x Thickness mm.)

Number Per Unit 4 4 4

127408-YIM-B-0606

Max

Fuse

Size

(Amps)

4 HP

(3 kW)

†

ActualkWHeater

Amps

Min. Cir-

cuit

Ampacity

(Amps)

4 HP

(3 kW)

MCA
w/Power
Exhaust

(Amps)

4 HP

(3 kW)

Models

090 120 150

12 x 12

(305 x 305)

10.6 (0.98) 13.2 (1.23) 13.2 (1.23)

3700 (1.75) 3700 (1.75) 3700 (1.75)

9.2 (.86) 14.5 (1.35) 14.5 (1.35)

25 x 16 x 2

(635 x 406 x 51)

15 x 15

(381 x 381)

25 x 20 x 2

(635 x 508 x 51)

15 x 15

(381 x 381)

25 x 20 x 2

(635 x 508 x 51)

Max Fuse

Size
w/Power
Exhaust

(Amps)

4 HP

(3 kW)

20 Unitary Products Group

127408-YIM-B-0606

OPTIONAL ELECTRIC HEAT

The factory-installed heaters are wired for single point power
supply. Power supply need only be brought into the single
point terminal block.

These CSA approved heaters are located within the central
compartment of the unit with the heater elements extending
into the supply air chamber.

Fuses are supplied, where required, by the factory. Some kW
sizes require fuses and other do not. Refer to Table 14 for
minimum CFM limitations and to Tables 10 through 12 for
electrical data.

T ABLE 14: ELECTRIC HEAT MINIMUM SUPPLY AIR

CFM

IMPERIAL

HEATER UNIT MODEL SIZE, NOMINAL TONS

kW

18
24
36
54

VOLTAGE

9

380/415

10 12.5

MINIMUM SUPPLY AIR CFM

N/A N/A
3000 3750
3000 3750
3000 3750
3000 3750

GAS PIPING

Proper sizing of gas piping depends on the cubic feet per
hour of gas flow required, specific gravity of the gas and the
length of run. "National Fuel Gas Code" Z223.1 should be
followed in all cases unless superseded by local codes or gas
utility requirements. Refer to the Pipe Sizing Table 16. The
heating value of the gas may differ with locality. The value
should be checked with the local gas utility.

NOTE: There may be a local gas utility requirement specify-

ing a minimum diameter for gas piping. All units
require a one-inch pipe connection at the entrance
fitting.

O P T I O N A L
C O I L
G U A R D
S H O W N

METRIC

HEATER UNIT MODEL SIZE, NOMINAL TONS

kW

18
24
36
54

VOLTAGE

9

380/415

10 12.5

MINIMUM SUPPLY AIR CFM

N/A N/A

1.41 1.76

1.41 1.76

1.41 1.76

1.41 1.76

OPTIONAL GAS HEAT

These gas-fired heaters have aluminized-steel or optional
stainless steel, tubular heat exchangers with spark ignition.

TABLE 15: GAS APPLICATION DATA

Unit

Size Opt.

090

120 15 175 140 15-45
150 15 175 140 10-40

Input (MBH) Output (MBH) Temp Rise (°F)

10 120 96 15-45
15 175 140 30-60

FIGURE 21 - SIDE ENTRY GAS PIPING

OPTIONAL
COIL
GUARD
SHOWN

FIGURE 22 - BOTTOM ENTRY GAS PIPING

Unitary Products Group 21

127408-YIM-B-0606

TABLE 16: GAS PIPE SIZING - CAPACITY OF PIPE

Length of

Pipe ft. (m)

10 (3)
20 (6)

30 (9.1)
40 (12.1)
50 (15.2)
60 (18.2)
70 (21.3)
80 (24.3)
90 (27.4)

100 (30.4)

3/4 in. 1 in. 1 -1/4 in.

278 (7.8) 520 (14.7) 1050 (29.7)
190 (5.3) 350 (9.9) 730 (20.6)
152 (4.3) 285 (8) 590 (16.7)
130 (3.6) 245 (6.9) 500 (14.1)

115 (3.2) 215 (6) 440 (12.4)

105 (2.9) 195 (5.5) 400 (12.4)

96 (2.7) 180 (5) 370 (10.4)
90 (2.5) 170 (4.8) 350 (9.9)
84 (2.3) 160 (4.5) 320 (9)
79 (2.2) 150 (4.2) 305 (8.6)

NOTE: Maximum capacity of pipe in cubic feet of gas per

hour based upon a pressure drop of 0.3 in ch W.C.
and 0.6 specific gravity gas.

NOTE: There may be a local gas utility requirement specify-

ing a minimum diameter for gas piping. All units
require a 3/4 inch pipe connection at the entrance
fitting. Line should not be sized smaller than the
entrance fitting size.

GAS CONNECTION

The gas supply line can be routed within the space and roof
curb, exiting through the unit’s basepan. Refer to Figure 9 for
the gas piping inlet location. Typical supply piping arrange­ments are shown in Figures 21 and 22. All pipe nipples, fit­tings, and the gas cock are field supplied or may be
purchased in UPG accessory kit #1GP0404.

Nominal Iron Pipe Size

4. All piping should be cleaned of dirt and scale by ham­mering on the outside of the pipe and blowing out loose
particles. Before initial start-up, be sure that all gas lines
external to the unit have been purged of air.

5. The gas supply should be a separate line and installed in
accordance with all safety codes as prescribed under
“Limitations”.

6. A 1/8-inch (3.175 mm) NPT plugged tapping, accessible
for test gage connection, must be installed immediately
upstream of the gas supply connection to the unit.

7. After the gas connections have been completed, op en
the main shut-off valve admitting normal gas pressure to
the mains. Check all joints for leaks with soap solution or

other material suitable for the purpose. NEVER USE A
FLAME.

FIRE OR EXPLOSION HAZARD
Failure to follow the safety warning exactly could

result in serious injury, death or property damage.
Never test for gas leaks with an open flame. Use a

commercially available soap solution made specifi­cally for the detection of leaks to check all connec­tions. A fire or explosion may result causing property
damage, personal injury or loss of life.

Gas piping recommendations

:

The furnace and its individual shut-off valve must be
disconnected from the gas supply piping system

1. A drip leg and a ground joint union must be installed in
the gas piping.

2. Where required by local codes, a manual shut-off valve
must be installed outside of the unit.

during any pressure testing at pressures in excess
of 1/2 PSIG.

Pressures greater than 1/2 PSIG will cause gas
valve damage resulting in a hazardous condition. If it
is subjected to a pressure greater than 1/2 PSIG, the

3. Use wrought iron or steel pipe for all gas lines. Pipe dope
should be applied sparingly to male threads only.

gas valve must be replaced.
The furnace must be isolated from the gas supply

piping system by closing its individual manual shut­off valve during any pressure testing of the gas sup­ply piping system at test pressures equal to or less

Natural gas may contain some propane. Propane is

than 1/2 PSIG.

an excellent solvent and will quickly dissolve white
lead and most standard commercial compounds. A
special pipe dope must be used when assembling
wrought iron or steel pipe. Shellac based com­pounds such as Gaskolac or Stalastic, and com­pounds such as Rectorseal #5, Clydes’s or John
Crane may be used.

Threaded joints should be coated with a sealing
compound that is resistant to the action of liquefied
petroleum gases. Do not use Teflon tape.

22 Unitary Products Group

127408-YIM-B-0606

LP UNITS, TANKS AND PIPING

All gas heat units are shipped from the factory equipped for
natural gas use only. The unit may be converted in the field
for use with LP gas with accessory kit model number
1NP0441.

All LP gas equipment must conform to the safety standards of
the National Fire Protection Association.

For satisfactory operation, LP gas pressure must be 10.5
inch W.C. at the unit under full load. Maintaining proper gas
pressure depends on three main factors:

1. The vaporization rate which depends on the temperature
of the liquid and the “wetted surface” area of the con­tainer(s).

2. The proper pressure regulation. (Two-st age regulation is
recommended).

3. The pressure drop in the lines between regu lators and
between the second stage regulator and the appliance.
Pipe size required will depend on the length of the pipe
run and the total load of all appliances.

Complete information regarding tank sizing for vaporization,
recommended regulator settings, and pipe sizing is available
from most regulator manufacturers and LP gas suppliers.

LP gas is an excellent solvent and will quickly dissolve white
lead and most standard commercial compounds. A special
pipe dope must be used when assembling wrought iron or
steel pipe for LP. Shellac base compounds such as Gaskolac
or Stalastic, and compounds such as Rectorseal #5, Clyde’s,
or John Crane may be used.

Check all connections for leaks when piping is completed
using a soap solution. NEVER USE A FLAME.

with screen. If necessary, a flue exhaust extension may be
installed at the point of installation.

OPTIONS/ACCESSORIES

ELECTRIC HEAT

Electric heaters are available as field installed accessories.
Refer to electric heat instructions for installation. These heat­ers mount in the heat compartment with the heating elements
extending into the supply air chamber. All electric heaters are
fused and intended for use with single point power supply.

MOTORIZED OUTDOOR DAMPER

The Motorized Outdoor Damper can be a factory installed
option or a field installed accessory. If factory installed, refer
to the instructions included with the outdoor air hood to com­plete the assembly. Field installed Motorized Outdoor
Damper accessories include complete instructions for instal­lation.

ECONOMIZER

The Economizer can be a factory installed option or a field
installed accessory. If factory installed, refer to the instruc­tions included with the outdoor air hood to complete the
assembly. Field installed Economizer accessories include
complete instructions for installation.

There are two Economizer options:

1. Down Flow application with barometric relief hood stan­dard.

2. Horizontal Flow application that requires the purchase of
a barometric relief hood.

POWER EXHAUST

The Power Exhaust can be a factory installed option or a field
installed accessory. If factory installed, refer to the instruc-

FIRE OR EXPLOSION HAZARD

Failure to follow the safety warning exactly could
result in serious injury, death or property damage.

Never test for gas leaks with an open flame. Use a
commercially available soap solution made specifi­cally for the detection of leaks to check all connec­tions. A fire or explosion may result causing property
damage, personal injury or loss of life.

VENT AND COMBUSTION AIR

Venting slots in the heating compartment access panel
remove the need for a combustion air hood. The gas heat
flue exhaust is routed through factory installed exhaust piping

Unitary Products Group 23

tions included with the outdoor air hood to complete the
assembly. Field installed Power Exhaust accessories include
complete instructions for installation.

The Power Exhaust factory installed option is for Down Flow
application only.

There are two field installed Power Exhaust accessories:

1. Down Flow application.

2. Horizontal Flow application that requires the purchase of
a barometric relief hood.

RAIN HOOD

All of the hood components, including the filters, the gasket­ing and the hardware for assembling, are packaged and
located between the condenser coil section and the main unit

127408-YIM-B-0606

cabinet, if the unit has factory installed options. If field
installed accessories are being installed all parts necessary
for the installation comes in the accessory.

ECONOMIZER AND POWER EXHAUST SET POINT
ADJUSTMENTS AND INFORMATION

Remove the top rear access panel from the unit. Locate the
economizer control module, where the following adjustments
will be made.

Extreme care must be exercised in turning all set
point, maximum and minimum damper positioning
adjustment screws to prevent twisting them off.

MINIMUM POSITION ADJUSTMENT

• Check that the damper blades move smoothly without
binding; carefully turn the Minimum Position Adjust
screw (found on the damper control module) fully clock­wise and then set the thermostat indoor fan switch to the
ON position and then OFF or energize and de-energize
terminals “R” to “G”.

• With the thermostat set to the indoor fan ON position or
terminals “R” to “G” energized, turn the Minimum Posi­tion Adjusting screw (located on the damper control
module) counterclockwise until the desired minimum
damper position has been attained.

ENTHALPY SET POINT ADJUSTMENT

The enthalpy set point may now be set by selecting the
desired set point shown in the Enthalpy Set Point Adjustment
Figure 23. Adjust as follows:

• For a single enthalpy operation carefully turn the set
point adjusting screw (found on the damper control
module) to the "A", "B", "C" or "D" setting correspondin g

to the lettered curve of the Enthalpy Set Point Adjust­ment Figure 23.

• For a dual enthalpy operation, carefully turn the set point
adjusting screw fully clockwise past the "D" setting.

POWER EXHAUST DAMPER SET POINT (WITH OR WITH­OUT POWER EXHAUST)

• With no power exhaust option, adjust the Exhaust Air
Adjustment Screw fully clockwise. This will allow 2nd
stage cooling to operate.

• With power exhaust option, each building pressurization
requirement will be different. The point at which the
power exhaust comes on is determined by the econo­mizer damper position (Percent Open). The Exhaust Air
Adjustment Screw should be set at the Percent Open of
the economizer damper at which the power exhaust is
needed. It can be set from 0 to 100% damper open.

INDOOR AIR QUALITY AQ

Indoor Air Quality (indoor sensor input): Terminal AQ accepts
a +2 to +10 Vdc signal with respect to the (AQ1) terminal.
When the signal is below it's set point, the actuator is allowed
to modulate normally in accordance with the enthalpy and
mixed air sensor inputs. When the AQ signal exceeds it's set
point setting and there is no call for free cooling, the actuator
is proportionately modulated from the 2 to 10 Vdc signal, with
2 Vdc corresponding to full closed and 10 Vdc corresponding
to full open. When there is no call for free cooling, the damper
position is limited by the IAQ Max damper position setting.
When the signal exceeds it's set point (Deman d C ontrol Ven­tilation Set Point) setting and there is a call for free cooling,
the actuator modulates from the minimum position to the full
open position based on the highest call from either the mixed
air sensor input or the AQ voltage input.

• Optional CO

• Optional CO

Space Sensor Kit Part # 2AQ04700324

2

Sensor Kit Part # 2AQ04700424

2

Replace the top rear access panel on the unit.

24 Unitary Products Group

127408-YIM-B-0606

40

(4)

70

(21)

50

(10)

55

(13)

60

(16)

65

(18)

35
(2)

45
(7)

75

(24)

80

(27)

35
(2)

40

(4)45(7)

50

(10)55(13)

60

(16)

65

(18)

70

(21)

75

(24)80(27)

85

(29)

85

(29)

90

(32)

90

(32)

105
(41)

110
(43)

100
(38)

95

(35)

95

(35)

100
(38)

105

(41)

110
(43)

APPROXIMATE DRY BULB TEMPERATURE - 0F (0C)

D

D

C

C

B

B

A

A

CONTROL

CURVE

CONTROL POINT

APPROX.

0

F (0C)

AT 50% RH

A

D

C

B

63 (17)

73 (23)

70 (21)
67 (19)

FIGURE 23 - ENTHALPY SET POINT CHART

Exhaust Air
Adjustment

Screw

Exhaust Air LED

Damper Min.

Position

Screw

Indoor Air Quality

Max. Adjustment

Screw

Indoor Air Quality

LED

Indoor Air Quality

Min. Adjustment

Screw

Free Cooling LED

Economizer Enthalpy
Set Point Adjustment

Screw

SO+ SO

SR+

N

N1

P1

T1

T

AQ1 AQ

SR

EXH

Set

EXH

P

Min

Pos

IAQ
Max

IAQ

IAQ

Min

Free
Cool

BC

A

D

TR TR1

24

Vac

HOT

+

1

3

EF EF1

24

Vac

COM

2

5

4

FIGURE 24 - HONEYWELL ECONOMIZER CONTROL W7212

Unitary Products Group 25

PHASING

Predator® units are properly phased at the factory. Check for
proper compressor rotation. If the blower or compressors
rotate in the wrong direction at start-up, the electrical connec­tion to the unit is misphased. Change the phasing of the Field

Line Connection at the factory or field supplied discon­nect to obtain proper rotation. (Scroll compressors operate in

only one direction. If the scroll is drawing low amperage, has
similar suction and discharge pressures, or producing a high
noise level, the scroll is misphased.)

127408-YIM-B-0606

A

C*

* NEVER LOOSEN

A

B

A

Scroll compressors require proper rotation to oper­ate correctly. Units are properly phased at the fac­tory. Do not change the internal wiring to make the
blower condenser fans, or compressor rotate cor­rectly.

BLOWER ROTATION

Check for proper supply air blower rotation. If the blower is
rotating backwards, the line voltage at the unit point of power
connection is misphased (See ‘PHASING’).

TABLE 17: SUPPLY AIR LIMITATIONS

Unit Size

090
120
150

Minimum

3

CFM (m

/sec)

2250 (1) 3750 (1.7)
3000 (1.4) 5000 (2.3)
3750 (1.7) 6250 (2.9)

Maximum

CFM (m3/sec)

BELT TENSION

The tension on the belt should be adjusted as shown in
Figure 25.

SPAN LENGTH

DEFL. FORCE

FIGURE 25 - BELT ADJUSTMENT

Procedure for adjusting belt tension:

1. Loosen six nuts (top and bottom) A.

2. Adjust by turning (B).

3. Never loosen nuts (C).

4. Use belt tension checker to apply a perpendicular
force to one belt at the midpoint of the span as
shown. Deflection distance of 4mm (5/32”) is
obtained.

To determine the deflection distance from normal
position, use a straight edge from sheave to sheave
as reference line. The recommended deflection
force is as follows:

Tension new belts at the max. deflection force rec­ommended for the belt section. Check the belt ten­sion at least two times during the first 24 hours of
operation. Any retensioning should fall between the
min. and max. deflection force values.

5. After adjusting retighten nuts (A).

26 Unitary Products Group

127408-YIM-B-0606

TABLE 18: BLOWER PERFORMANCE 7-1/2 TON STANDARD MOTOR - SIDE DUCT (IMPERIAL)

ESP

(iwg)

CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP

0.2 – – – – – – – – – – – – 3193 1490 1.60 2981 1310 1.41

0.4 3690 2230 2.39 3468 1950 2.09 3294 1750 1.88 3105 1550 1.66 2922 1370 1.47 2694 1210 1.30

0.6 3478 2110 2.26 3239 1830 1.96 3044 1640 1.76 2850 1440 1.54 2651 1270 1.36 2423 1120 1.20

0.8 3243 1980 2.12 3001 1720 1.85 2790 1520 1.63 2576 1330 1.43 2370 1170 1.26 2105 1020 1.09

1.0 3006 1830 1.96 2758 1580 1.70 2544 1400 1.50 2303 1230 1.32 2017 1050 1.13 1624 880 0.94

1.2 2758 1720 1.85 2533 1510 1.62 2230 1290 1.38 1891 1080 1.16 – – – – – –

1.4 2447 1570 1.68 2182 1350 1.45 1769 1110 1.19 – – – – – – – – –

1.6 2085 1410 1.51 – – – – – – – – – – – – – – –

012345

Turns Open

TABLE 19: BLOWER PERFORMANCE 7-1/2 TON STANDARD MOTOR - SIDE DUCT (METRIC)

Turns Open

ESP

(Pa)

m

50 – – – – – – – – – – – – 1.51 1.49 1.19 1.36 1.31 1.05
100 1.74 2.23 1.78 1.64 1.95 1.55 1.55 1.75 1.40 1.46 1.55 1.24 1.38 1.37 1.10 1.27 1.21 0.97
149 1.64 2.11 1.68 1.53 1.83 1.46 1.44 1.64 1.39 1.34 1.44 1.15 1.25 1.27 1.01 1.14 1.12 0.89
199 1.53 1.98 1.58 1.42 1.72 1.38 1.32 1.52 1.38 1.22 1.33 1.07 1.12 1.17 0.94 0.99 1.02 0.81
249 1.42 1.83 1.46 1.30 1.58 1.27 1.20 1.40 1.28 1.09 1.23 0.98 0.95 1.05 0.84 0.77 0.88 0.70
299 1.30 1.72 1.38 1.20 1.51 1.21 1.05 1.29 1.17 0.89 1.08 0.91 – – – – – –
349 1.15 1.57 1.25 1.03 1.35 1.08 0.83 1.11 1.01 – – – – – – – – –
399 0.98 1.41 1.26 – – – – – – – – – – – – – – –

012345

In

(kW)

Out

(kW)

m3/s

3

/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

TABLE 20: BLOWER PERFORMANCE 7-1/2 TON OPTIONAL MOTOR - SIDE DUCT (IMPERIAL)

ESP

(iwg)

CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP

0.8 – – – – – – – – – – – – 2783 1500 1.61 2507 1300 1.39

1.0 3555 2440 2.62 3285 2120 2.27 3047 1860 2.00 2778 1590 1.71 2507 1390 1.49 2209 1180 1.27

1.2 3320 2310 2.48 3034 1990 2.13 2799 1730 1.86 2510 1480 1.59 2213 1260 1.35 1846 1050 1.13

1.4 3101 2160 2.32 2796 1860 2.00 2466 1590 1.71 2188 1330 1.43 1721 1090 1.17 – – –

1.6 2864 2040 2.19 2489 1710 1.83 2145 1450 1.56 – – – – – – – – –

1.8 2524 1860 2.00 2182 1550 1.66 – – – – – – – – – – – –

2.0 2189 1680 1.80 – – – – – – – – – – – – – – –

012345

Turns Open

TABLE 21: BLOWER PERFORMANCE 7-1/2 TON OPTIONAL MOTOR - SIDE DUCT (METRIC)

Turns Open

ESP
(Pa)

m3/s

100––––––––––––1.311.51.201.181.31.04

149 1.68 2.44 1.95 1.55 2.12 1.70 1.44 1.86 1.49 1.31 1.59 1.27 1.18 1.39 1.11 1.04 1.18 0.94

199 1.52 2.31 1.85 1.43 1.99 1.59 1.32 1.73 1.38 1.18 1.48 1.18 1.04 1.26 1.01 0.87 1.05 0.84

249 1.46 2.16 1.73 1.31 1.86 1.49 1.16 1.59 1.27 1.03 1.33 1.06 0.81 1.09 0.87 – – –

299 1.35 2.04 1.63 1.17 1.71 1.36 1.01 1.45 1.16 – – – – – – – – –

349 1.19 1.86 1.49 1.03 1.55 1.24 – – – – – – – – – – – –

399 1.03 1.68 1.34 – – – – – – – – – – – – – – –

012345

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

Unitary Products Group 27

127408-YIM-B-0606

TABLE 22: BLOWER PERFORMANCE 10 TON STANDARD MOTOR - SIDE DUCT (IMPERIAL)

ESP

(iwg)

CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP

4820 2675 2.87 4582 2362 2.53 4319 2080 2.23 4086 1842 1.98 3863 1648 1.77 3590 1430 1.53

0.4
4522 2496 2.68 4307 2215 2.38 4025 1941 2.08 3713 1678 1.80 3464 1499 1.61 3149 1291 1.38

0.6
4223 2332 2.50 3973 2062 2.21 3656 1783 1.91 3363 1550 1.66 3026 1350 1.45 - - -

0.8
3913 2174 2.33 3679 1923 2.06 3262 1619 1.74 2721 1330 1.43 - - - - - -

1.0
3521 1978 2.12 3104 1693 1.82 - - - - - - - - - - - -

1.2
2790 1660 1.78 - - - - - - - - - - - - - - -

1.4

012345

Turns Open

TABLE 23: BLOWER PERFORMANCE 10 TON STANDARD MOTOR - SIDE DUCT (METRIC)

Turns Open

ESP
(Pa)

m

2.27 2.68 2.14 2.16 2.36 1.89 2.04 2.08 1.66 1.93 1.84 1.47 1.82 1.65 1.32 1.69 1.43 1.14

100

2.13 2.50 2.00 2.03 2.22 1.77 1.90 1.94 1.55 1.75 1.68 1.34 1.63 1.50 1.20 1.49 1.29 1.03

149

1.99 2.33 1.87 1.88 2.06 1.65 1.73 1.78 1.43 1.59 1.55 1.24 1.43 1.35 1.08 - - -

199

1.852.171.741.741.921.541.541.621.301.281.331.06------

249

1.661.981.581.461.691.35------------

299

1.321.661.33---------------

349

012345

In

(kW)

Out

(kW)

m3/s

3

/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

TABLE 24: BLOWER PERFORMANCE 10 TON OPTIONAL MOTOR - SIDE DUCT (IMPERIAL)

ESP

(iwg)

012345

CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

---------------496024952.68

- - - - - - - - - - - - 5091 2745 2.94 4646 2314 2.48

- - - - - - - - - 5078 2937 3.15 4839 2584 2.77 4347 2153 2.31

- - - - - - 5075 3117 3.34 4767 2730 2.93 4487 2377 2.55 3946 1942 2.08

- - - 5068 3308 3.55 4742 2881 3.09 4427 2513 2.69 4108 2159 2.32 3501 1723 1.85
5079 3595 3.86 4787 3105 3.33 4452 2713 2.91 4012 2259 2.42 3665 1926 2.07 - - ­4739 3316 3.56 4482 2892 3.10 4098 2474 2.65 3543 2006 2.15 3057 1642 1.76 - - ­4461 3111 3.34 4070 2621 2.81 3552 2160 2.32 - - - - - - - - ­3997 2782 2.98 3400 2219 2.38 - - - - - - - - - - - ­3496 2480 2.66 - - - - - - - - - - - - - - -

Turns Open

28 Unitary Products Group

127408-YIM-B-0606

TABLE 25: BLOWER PERFORMANCE 10 TON OPTIONAL MOTOR - SIDE DUCT (METRIC)

Turns Open

ESP

(Pa)

m3/s

100
149
199
249
299
349

2.40 3.60 2.88 2.26 3.11 2.48 2.10 2.71 2.17 1.89 2.26 1.81 1.73 1.93 1.54 - - -

399

2.24 3.32 2.65 2.12 2.89 2.31 1.93 2.47 1.98 1.67 2.01 1.60 1.44 1.64 1.31 - - -

448

2.113.112.491.922.622.101.682.161.73---------

498

1.892.782.231.602.221.78------------

548

1.652.481.98---------------

012345

In

Out

(kW)

m3/s

(kW)

---------------2.342.502.00

------------2.402.752.202.192.311.85

---------2.402.942.352.282.582.072.052.151.72

- - - - - - 2.40 3.12 2.49 2.25 2.73 2.18 2.12 2.38 1.90 1.86 1.94 1.55

- - - 2.39 3.31 2.65 2.24 2.88 2.30 2.09 2.51 2.01 1.94 2.16 1.73 1.65 1.72 1.38

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

TABLE 26: BLOWER PERFORMANCE 12-1/2 TON - SIDE DUCT (IMPERIAL)

Turns Open

ESP

(iwg)

CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP

0.4

0.6

5870 4273 4.58 5567 3715 3.98 5406 3380 3.62 5078 2937 3.15 4839 2584 2.77 4347 2153 2.31

0.8

5652 4087 4.38 5327 3518 3.77 5075 3117 3.34 4767 2730 2.93 4487 2377 2.55 3946 1942 2.08

1.0

5350 3820 4.10 5068 3308 3.55 4742 2881 3.09 4427 2513 2.69 4108 2159 2.32 - - -

1.2

5079 3595 3.86 4787 3105 3.33 4452 2713 2.91 4012 2259 2.42 3665 1926 2.07 - - -

1.4

4739 3316 3.56 4482 2892 3.10 4098 2474 2.65 - - - - - - - - -

1.6

4461 3111 3.34 4070 2621 2.81 - - - - - - - - - - - -

1.8

3997 2782 2.98 - - - - - - - - - - - - - - -

2.0

012345

- - - 6130 4171 4.47 5915 3774 4.05 5610 3309 3.55 5396 2948 3.16 4960 2495 2.68

- - - 5850 3932 4.22 5648 3565 3.82 5363 3136 3.36 5091 2745 2.94 4646 2314 2.48

m3/s

In

(kW)

Out

(kW)

TABLE 27: BLOWER PERFORMANCE 12-1/2 TON - SIDE DUCT (METRIC)

Turns Open

ESP
(Pa)

m3/s

100
149

2.77 4.27 3.42 2.63 3.72 2.97 2.55 3.38 2.70 2.40 2.94 2.35 2.28 2.58 2.07 2.05 2.15 1.72

199

2.67 4.09 3.27 2.51 3.52 2.81 2.40 3.12 2.49 2.25 2.73 2.18 2.12 2.38 1.90 1.86 1.94 1.55

249

2.52 3.82 3.06 2.39 3.31 2.65 2.24 2.88 2.30 2.09 2.51 2.01 1.94 2.16 1.73 - - -

299

2.40 3.60 2.88 2.26 3.11 2.48 2.10 2.71 2.17 1.89 2.26 1.81 1.73 1.93 1.54 - - -

349

2.243.322.652.122.892.311.932.471.98---------

399

2.113.112.491.922.622.10-- ---------

448

1.892.782.23---------------

498

Unitary Products Group 29

012345

In

Out

(kW)

m3/s

(kW)

- - - 2.89 4.17 3.34 2.79 3.77 3.02 2.65 3.31 2.65 2.55 2.95 2.36 2.34 2.50 2.00

- - - 2.76 3.93 3.15 2.67 3.57 2.85 2.53 3.14 2.51 2.40 2.75 2.20 2.19 2.31 1.85

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

127408-YIM-B-0606

TABLE 28: BLOWER PERFORMANCE 7-1/2 TON STANDARD MOTOR - DOWNSHOT (IMPERIAL)

Turns Open

ESP

(iwg)

CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP
3478 2110 2.26 3239 1830

0.2

3243 1980 2.12 3001 1720

0.4

3006 1830 1.96 2758 1580

0.6

2758 1720 1.85 2533 1510

0.8

2447 1570 1.68 2182 1350

1.0

2085 1410 1.51 – –

1.2

012345

1.96

1.85

1.70

1.62

1.45
–

3044 1640
2790 1520
2544 1400
2230 1290
1769 1110

––

1.76

1.63

1.50

1.38

1.19
–

2850 1440
2576 1330
2303 1230
1891 1080

––
––

1.54

1.43

1.32

1.16
–
–

2651 1270
2370 1170
2017 1050

––
––
––

1.36

1.26

1.13
–
–
–

2423 1120
2105 1020
1624 880

––
––
––

TABLE 29: BLOWER PERFORMANCE 7-1/2 TON STANDARD MOTOR - DOWNSHOT (METRIC)

Turns Open

ESP

(Pa)

m3/s

50

1.64 2.11 1.68 1.53 1.83

100

1.53 1.98 1.58 1.42 1.72

149

1.42 1.83 1.46 1.30 1.58

199

1.30 1.72 1.38 1.20 1.51

249

1.15 1.57 1.25 1.03 1.35

299

0.98 1.41 1.26 – –

012345

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

1.46

1.38

1.27

1.21

1.08
–

m3/s

1.44 1.64

1.32 1.52

1.20 1.40

1.05 1.29

0.83 1.11

In

(kW)

––

Out

(kW)

1.39

1.38

1.28

1.17

1.01
–

m3/s

1.34 1.44

1.22 1.33

1.09 1.23

0.89 1.08

In

(kW)

––
––

Out

(kW)

1.15

1.07

0.98

0.91
–
–

m3/s

1.25 1.27

1.12 1.17

0.95 1.05

In

(kW)

––
––
––

Out

(kW)

1.01

0.94

0.84
–
–
–

m3/s

1.14 1.12

0.99 1.02

0.77 0.88
––
––
––

In

(kW)

1.20

1.09

0.94
–
–
–

Out

(kW)

0.89

0.81

0.70
–
–
–

TABLE 30: BLOWER PERFORMANCE 7-1/2 TON OPTIONAL MOTOR - DOWNSHOT (IMPERIAL)

Turns Open

ESP

(iwg)

CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP

0.4

0.6

0.8

3101 2160 2.32 2796 1860

1.0

2864 2040 2.19 2489 1710

1.2

2524 1860 2.00 2182 1550

1.4

2189 1680 1.80 – –

1.6

30 Unitary Products Group

012345

–––––
–––32852120
–––30341990

2.27

2.13

2.00

1.83

1.66

–

3047 1860
2799 1730
2466 1590
2145 1450

–

––

––
––

–

2.00

1.86

1.71

1.56
–
–

–––2783 1500
2778 1590
2510 1480
2188 1330

––

––

––

1.71

1.59

1.43
–
–
–

2507 1390
2213 1260
1721 1090

––
––
––

1.61

1.49

1.35

1.17
–
–
–

2507 1300
2209 1180
1846 1050

––
––
––
––

1.39

1.27

1.13
–
–
–
–

127408-YIM-B-0606

TABLE 31: BLOWER PERFORMANCE 7-1/2 TON OPTIONAL MOTOR - DOWNSHOT (METRIC)

Turns Open

ESP

(Pa)

m3/s

100
149

1.67 2.44 1.95 1.55 2.12

199

1.57 2.31 1.85 1.43 1.99

249

1.46 2.16 1.73 1.31 1.86

299

1.35 2.04 1.63 1.17 1.71

349

1.19 1.86 1.49 1.03 1.55

399

1.03 1.68 1.34 – –

012345

In

Out

(kW)

m3/s

(kW)

–––––

In

(kW)

Out

(kW)

–

1.70

1.59

1.49

1.36

1.24
–

m3/s

1.44 1.86

1.32 1.73

1.16 1.59

1.01 1.45

In

(kW)

––

––
––

Out

(kW)

–

1.49

1.38

1.27

1.16
–
–

In

(kW)

Out

(kW)

1.27

1.18

1.06
–
–
–

m3/s

1.18 1.39

1.04 1.26

0.81 1.09
––
––
––

m3/s

–––1.31 1.5

1.31 1.59

1.18 1.48

1.03 1.33
––
––
––

In

(kW)

Out

(kW)

1.20

1.11

1.01

0.87
–
–
–

m3/s

1.18 1.3

1.04 1.18

0.87 1.05

TABLE 32: BLOWER PERFORMANCE 10 TON STANDARD MOTOR - DOWNSHOT (IMPERIAL)

Turns Open

ESP

(iwg)

CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP

4543 2511 2.69 4362 2250 2.41 4139 1996 2.14 3911 1766

0.2

4311 2381

0.4

4032 2232

0.6

3706 2068

0.8

3333 1892

1.0

2914 1711

1.2

012345

2.55

2.39

2.22

2.03

1.83

4115 2127
3804 1982
3428 1818
2989 1644

--

2.28

2.13

1.95

1.76

-

3862 1871
3508 1720
3078 1548

--

--

2.01

1.84

1.66

-

-

1.89

3719 1594
3611 1644
3246 1506

---------

---------

---------

1.76

3386 1471

1.61

2971 1332 1.43 - - -

1.71

1.58

3518 1407
3153 1293

In

(kW)

––
––
––
––

Out

(kW)

1.04

0.94

0.84
–
–
–
–

1.51

1.39

TABLE 33: BLOWER PERFORMANCE 10 TON STANDARD MOTOR - DOWNSHOT (METRIC)

Turns Open

ESP
(Pa)

m3/s

50

2.14 2.51 2.01 2.06 2.25 1.80 1.95 2.00 1.60 1.85 1.77 1.41 1.75 1.59 1.27 1.66 1.41 1.13

100

2.03 2.38 1.91 1.94 2.13 1.70 1.82 1.87 1.50 1.70 1.64 1.31 1.60 1.47 1.18 1.49 1.29 1.03

149

1.90 2.23 1.79 1.80 1.98 1.59 1.66 1.72 1.38 1.53 1.51 1.20 1.40 1.33 1.07 - - -

199

1.752.071.651.621.821.451.451.551.24---------

249

1.571.891.511.411.641.32------------

299

1.381.711.37--------------

Unitary Products Group 31

012345

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

127408-YIM-B-0606

TABLE 34: BLOWER PERFORMANCE 10 TON OPTIONAL MOTOR - DOWNSHOT (IMPERIAL)

Turns Open

ESP

(iwg)

CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP

0.2

0.4

0.6

0.8

4915 3456

1.0

4653 3253

1.2

4372 3046

1.4

4070 2837

1.6

3748 2629

1.8

3406 2425

2.0

3044 2228

2.2

012345

------------4966 2666

--

--

---4908 3197

-

-

3.71

3.49

3.27

3.04

2.82

2.60

2.39

--

---4929 3022

4651 3013
4377 2823
4087 2631
3780 2437
3455 2243
3114 2051

---------------

-

3.43

3.23

3.03

2.82

2.61

2.41

2.20

---4919 2473

3.24

4665 2324
4668 2841
4388 2656
4089 2467
3771 2277
3434 2089
3078 1904

--

3.05

4391 2171 2.33 4151 2183 2.34 3717 1829 1.96

2.85

4096 2015 2.16 3825 2008 2.15 3352 1664 1.78

2.65

3779 1858 1.99 3471 1830 1.96 2951 1499 1.61

2.44

3442 1703 1.83 3090 1652 1.77 - - -

2.24

3084 1552 1.66 - - - - - -

2.04

---------

-

---------

2.65

4721 2515

2.49

4450 2353 2.52 4048 1991 2.13

2.86

2.70

4605 2290
4344 2145

2.46

2.30

TABLE 35: BLOWER PERFORMANCE 10 TON OPTIONAL MOTOR - DOWNSHOT (METRIC)

Turns Open

ESP
(Pa)

m3/s

50
100
149
199
249

2.32 3.46 2.76 2.20 3.01 2.41 2.07 2.66 2.12 1.93 2.01 1.61 1.81 2.01 1.61 1.58 1.66 1.33

299

2.20 3.25 2.60 2.07 2.82 2.26 1.93 2.47 1.97 1.78 1.86 1.49 1.64 1.83 1.46 1.39 1.50 1.20

349

2.06 3.05 2.44 1.93 2.63 2.10 1.78 2.28 1.82 1.62 1.70 1.36 1.46 1.65 1.32 - - -

399

1.92 2.84 2.27 1.78 2.44 1.95 1.62 2.09 1.67 1.46 1.55 1.24 - - - - - -

448

1.77 2.63 2.10 1.63 2.24 1.79 1.45 1.90 1.52 - - - - - - - - -

498

1.61 2.43 1.94 1.47 2.05 1.64 - - - - - - - - - - - -

548

1.44 2.23 1.78 - - - - - - - - - - - - - - -

012345

In

Out

(kW)

m3/s

(kW)

- - - - - - - - - - - - 2.34 2.67 2.13 2.17 2.29 1.83

- - - - - - - - - 2.32 2.47 1.98 2.23 2.51 2.01 2.05 2.15 1.72

- - - - - - 2.33 3.02 2.42 2.20 2.32 1.86 2.10 2.35 1.88 1.91 1.99 1.59

- - - 2.32 3.20 2.56 2.20 2.84 2.27 2.07 2.17 1.74 1.96 2.18 1.75 1.75 1.83 1.46

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

32 Unitary Products Group

127408-YIM-B-0606

TABLE 36: BLOWER PERFORMANCE 12-1/2 TON - DOWNSHOT (IMPERIAL)

ESP

(iwg)

CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP CFM Watts BHP
5576 4015

0.4

5376 3839

0.6

5155 3652

0.8

4915 3456

1.0

4653 3253

1.2

4372 3046

1.4

4070 2837

1.6

3748 2629

1.8

012345

4.32

4.12

3.92

3.71

3.49

3.27

3.04

2.82

5370 3547
5147 3376
4908 3197
4651 3013
4377 2823
4087 3621
3780 2437

----- -------- --

3.80

5171 3197

3.62

4929 3022

3.43

4668 2841

3.23

4388 2656

3.03

4089 2467 2.65 3608 2051 2.20 - - - - - -

2.82

3771 2277 2.44 - - - - - - - - -

2.61

------------

Turns Open

3.43

5007 2884

3.24

4735 2704

3.05

4411 2501

2.85

4035 2281 2.45 3825 2008 2.15 - - -

3.09

4721 2515 2.70 4344 2145 2.30

2.90

4450 2353 2.52 4048 1991 2.13

2.68

4151 2183 2.34 3717 1829 1.96

TABLE 37: BLOWER PERFORMANCE 12-1/2 TON - DOWNSHOT (METRIC)

Turns Open

ESP

(Pa)

m3/s

100

2.63 4.01 3.21 2.53 3.55 2.84 2.44 3.20 2.56 2.36 2.88 2.31 2.23 2.51 2.01 2.05 2.15 1.72

149

2.54 3.84 3.07 2.43 3.38 2.70 2.33 3.02 2.42 2.23 2.70 2.16 2.10 2.35 1.88 1.91 1.99 1.59

199

2.43 3.65 2.92 2.32 3.20 2.56 2.20 2.84 2.27 2.08 2.50 2.00 1.96 2.18 1.75 1.75 1.83 1.46

249

2.32 3.46 2.76 2.20 3.01 2.41 2.07 2.66 2.12 1.90 2.28 1.83 1.81 2.01 1.61 - - -

299

2.203.252.602.072.822.261.932.471.971.702.051.64------

349

2.063.052.441.932.632.101.782.281.82---------

399

1.922.842.271.782.441.95------------

448

1.772.632.10---------------

012345

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

m3/s

In

(kW)

Out

(kW)

NOTES FOR TABLE 18 THROUGH TABLE 37:

• Blower performance includes dry coil and two-inch
filters.

• Blower performance for gas heat includes the maximum
number of heat tubes available for each tonnage.

• ESP (External Static Pressure) given is that available for
the supply and return air duct system. All internal resis­tances have been deducted from the total static pressure
of the blower.

•

TABLE 38: INDOOR BLOWER SPECIFICATIONS

MODEL

DM090

DM120

DM150

HP RPM Eff. SF Frame Datum Dia. (in.) Bore (in.) Model Datum Dia. (in.) Bore (in.) Model

3 1725 80% 1.15 56 3.4 - 4.4 7/8 1VM50 5.5 1 AK59 A49
3 1725 80% 1.15 56 3.4 - 4.4 7/8 1VM50 5.0 1 AK54 A49
2 1725 80% 1.15 56 3.4 - 4.4 7/8 1VM50 7 1 AK74 A54
4 1725 80% 1.15 184T 4.3 - 5.3 1-1/8 1VP56 6.2 1 BK72 BX56
4 1725 87% 1.15 184T 4.3 - 5.3 1-1/8 1VP56 6.2 1 BK72 BX56

Unitary Products Group 33

MOTOR MOTOR SHEAVE BLOWER SHEAVE

BELT

127408-YIM-B-0606

AIR BALANCE

Start the supply air blower motor. Adjust the resistances in both the supply and the return air duct systems to balance the air
distribution throughout the conditioned space. The job specifications may require that this balancing be done by someone other
than the equipment installer.

CHECKING AIR QUANTITY

METHOD ONE

1. Remove the dot plugs from the duct panel (for location of
the dot plugs see Figure 10).

2. Insert eight-inches of 1/4 inch metal tubing into the air­flow on both sides of the indoor coil.

NOTE: The tubes must be inserted and held in a position

perpendicular to the air flow so that velocity pres­sure will not affect the static pressure readings.

3. Use an Inclined Manometer or Magnehelic to determine
the pressure drop across a dry evaporator coil. Since the
moisture on an evaporator coil can vary greatly, measur­ing the pressure drop across a wet coil under field condi­tions could be inaccurate. To assure a dry coil, the
compressors should be de-activated while the test is
being run.

NOTE: De-energize the compressors before t aking any test

measurements to assure a dry evaporator coil.

4. The CFM through the unit can be determined from the
pressure drop indicated by the manometer by referring to
Figure 26. In order to obtain an accurate measurement,
be certain that the air filters are clean.

5. To adjust Measured CFM to Required CFM, see ’SUP­PLY AIR DRIVE ADJUSTMENT’.

6. After readings have been obtained, remove the tubes
and replace the dot plugs.

METHOD TWO

1. Drill two 5/16 inch holes, one in the return air duct as
close to the inlet of the unit as possible, and another in
the supply air duct as close to the outlet of the unit as
possible.

2. Using the whole drilled in step 1, insert eight inches of
1/4 inch metal tubing into the airflow of the return and
supply air ducts of the unit.

NOTE: The tubes must be inserted and held in position per-

pendicular to the airflow so that velocity pressure
will not affect the static pressure readings.

3. Use an Inclined Manometer or Magnehelic to determine
the pressure drop across the unit. This is the External
Static Pressure (ESP). In order to obtain an accurate
measurement, be certain that the air filters are clean.

4. Determine the number of turns the variable motor
sheave is open.

5. Select the correct blo wer performance table for the unit
from Tables 18 - 37. Tables are presented for horizontal
and downflow configuration.

6. Determine the unit Measured CFM from the Blower Per­formance Table, External Static Pressure and the num­ber of turns the variable motor sheave is open.

7. To adjust Measured CFM to Required CFM, see ’SUP­PL Y AIR DRIVE ADJUSTMENT’.

8. After reading has been obtained, remove the tubes and
seal holes.

NOTE: With the addition of field installed accessories

repeat this procedure.

Failure to properly adjust the total system air quan­tity can result in extensive blower damage.

Failure to properly adjust the total system air quan­tity can result in extensive blower damage.

34 Unitary Products Group

127408-YIM-B-0606

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

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,1'225&2,/35(6685('52396$,5)/2:



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FIGURE 26 - DRY COIL DELTA P 50" CABINET

35('$725&$%,1(7+=81,76

,1'225&2,/35(6685('52396$,5)/2:

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$LUIORZ&)0

FIGURE 27 - DRY COIL DELTA P 42" CABINET

Unitary Products Group 35

127408-YIM-B-0606

SUPPLY AIR DRIVE ADJUSTMENT

Before making any blower speed changes review
the installation for any installation errors, leaks or
undesirable systems effects that can result in loss of
airflow.

Even small changes in blower speed can result in
substantial changes in static pressure and BHP.
BHP and AMP draw of the blower motor will
increase by the cube of the blower speed. Static
pressure will increase by the square of the blower
speed. Only qualified personnel should make blower
speed changes, strictly adhering to the fan laws.

At unit start-up, the measured CFM may be higher or lower
than the required CFM. To achieve the required CFM, the
speed of the drive may have adjusted by changing the datum
diameter (DD) of the variable pitch motor sheave as
described below:

Required CFM

(

Measured CFM

Use the following tables and the DD calculated per the above
equation to adjust the motor variable pitch sheave.

• Existing DD = New DD

)

EXAMPLE
A 12.5 ton unit was selected to deliver 4,000 CFM with a 3

HP motor, but the unit is delivering 3,800 CFM. The variable
pitch motor sheave is set at 2 turns open.

Use the equation to determine the required DD for the new
motor sheave.

4,000 CFM

(

3,750 CFM
Use Table 43 to locate the DD nearest to 4.21 in. Close the

sheave to 1 turn open.
New BHP

= (Speed increase) • BHP at 3,800 CFM

= (Speed increase) • Original BHP
= New BHP

New motor Amps
= (Speed increase) • Amps at 3,800 CFM
= (Speed increase) • Original Amps

= New Amps

• 4.0 in. = 4.21 in.

)

3

3

3

3

36 Unitary Products Group

127408-YIM-B-0606

TABLE 39: ADDITIONAL STATIC RESISTANCE 50” CABINET (IMPERIAL)

CFM

Cooling Only

*

Economizer†

‡

Electric Heat KW

9 18243654

1900 0.06 0.02 0.05 0.06 0.07 0.08 0.10
2100 0.07 0.02 0.06 0.07 0.08 0.09 0.11
2300 0.08 0.02 0.07 0.08 0.09 0.10 0.13
2500 0.09 0.02 0.08 0.09 0.10 0.11 0.14
2700 0.11 0.03 0.09 0.10 0.12 0.13 0.16
2900 0.12 0.03 0.10 0.11 0.13 0.14 0.18
3100 0.14 0.03 0.12 0.13 0.15 0.16 0.20
3300 0.16 0.03 0.13 0.14 0.17 0.18 0.22
3500 0.18 0.04 0.15 0.16 0.19 0.20 0.24
3700 0.20 0.04 0.17 0.18 0.21 0.22 0.26
3900 0.23 0.04 0.19 0.20 0.23 0.24 0.28
4100 0.25 0.04 0.21 0.22 0.25 0.26 0.31
4300 0.28 0.05 0.23 0.24 0.28 0.29 0.34
4500 0.30 0.05 0.25 0.26 0.30 0.31 0.37
4700 0.33 0.05 0.28 0.29 0.33 0.34 0.40
4900 0.36 0.05 0.30 0.31 0.35 0.37 0.43
5100 0.39 0.06 0.33 0.34 0.38 0.40 0.46
5300 0.42 0.06 0.35 0.37 0.41 0.43 0.49
5500 0.45 0.06 0.38 0.40 0.44 0.46 0.53
5700 0.48 0.06 0.41 0.43 0.47 0.49 0.56
5900 0.52 0.07 0.44 0.46 0.50 0.53 0.59
6100 0.56 0.07 0.47 0.49 0.53 0.56 0.62
6300 0.60 0.07 0.50 0.53 0.56 0.59 0.65

*.

Add these resistance values to the available static resistance in the respective Blower Performance Tables.

†.

Deduct these resistance values from the available external static pressure shown in the respective Blower Performance Table.

‡.

The pressure drop through the economizer is greater for 100% outdoor air than for 100% return air. If the resistance of the return
air duct system is less than 0.25 IWG, the unit will deliver less CFM during full economizer operation.

†

TABLE 40: ADDITIONAL STATIC RESISTANCE 42” CABINET (IMPERIAL)

CFM

Cooling Only

1900 -0.004 0.07
2100 0.01 0.09
2300 0.01 0.11
2500 0.02 0.13
2700 0.03 0.16
2900 0.04 0.18
3100 0.05 0.20
3300 0.06 0.22
3500 0.07 0.24
3700 0.08 0.27
3900 0.09 0.29
4100 0.09 0.31
4300 0.10 0.33

*.

Add these resistance values to the available static resistance in the respective Blower Performance Tables.

†.

Deduct these resistance values from the available external static pressure shown in the respective Blower Performance Table.

‡.

The pressure drop through the economizer is greater for 100% outdoor air than for 100% return air. If the resistance of the return
air duct system is less than 0.25 IWG, the unit will deliver less CFM during full economizer operation.

*

Economizer†

‡

Unitary Products Group 37

127408-YIM-B-0606

TABLE 41: ADDITIONAL STATIC RESISTANCE 50” CABINET (METRIC)

M3S Cooling Only

*

Economizer†

‡

Electric Heat kW

9 18243654

0.89 14.9 5.0 12.4 14.9 17.4 19.9 24.8

0.99 17.4 5.0 14.9 17.4 19.9 22.4 27.3

1.08 19.9 5.0 17.4 19.9 22.4 24.8 32.3

1.18 22.4 5.0 19.9 22.4 24.8 27.3 34.8

1.27 27.3 7.5 22.4 24.8 29.8 32.3 39.7

1.36 29.8 7.5 24.8 27.3 32.3 34.8 44.7

1.46 34.8 7.5 29.8 32.3 37.3 39.7 49.7

1.55 39.7 7.5 32.3 34.8 42.2 44.7 54.6

1.65 44.7 9.9 37.3 39.7 47.2 49.7 59.6

1.74 49.7 9.9 42.2 44.7 52.2 49.7 64.6

1.83 57.1 9.9 47.2 49.7 57.1 59.6 69.5

1.93 62.1 9.9 52.2 54.6 62.1 64.6 77.0

1.02 69.5 12.4 57.1 59.6 69.5 72.0 84.4

2.12 74.5 12.4 62.1 64.6 74.5 77.0 91.9

2.21 82.0 12.4 69.5 72.0 82.0 84.4 99.3

2.30 89.4 12.4 74.5 77.0 86.9 91.9 106.8

2.40 96.9 14.9 82.0 84.4 94.4 99.3 114.2

2.49 104.3 14.9 86.9 91.9 101.8 106.8 121.7

2.59 111.8 14.9 94.4 99.3 109.3 114.2 131.6

2.68 119.2 14.9 101.8 106.8 116.7 121.7 139.1

2.77 129.1 17.4 109.3 114.2 124.2 131.6 146.5

2.87 139.1 17.4 116.7 121.7 131.6 139.1 154.0

2.96 149.0 17.4 124.2 131.6 139.1 146.5 161.4

*.

Add these resistance values to the available static resistance in the respective Blower Performance Tables.

†.

Deduct these resistance values from the available external static pressure shown in the respective Blower Performance Table.

‡.

The pressure drop through the economizer is greater for 100% outdoor air than for 100% return air. If the resistance of the return
air duct system is less than 62.1 Pa, the unit will deliver less M

3

S during full economizer operation.

†

TABLE 42: ADDITIONAL STATIC RESISTANCE 42” CABINET (METRIC)

CFM

Cooling Only

*

Economizer†

0.9 -0.99 17.40

0.99 2.50 22.40

1.09 2.50 27.40

1.18 4.98 32.40

1.27 7.50 39.90

1.37 10.00 44.83

1.46 12.50 49.81

1.56 14.90 54.80

1.65 17.40 59.80

1.75 19.90 67.20

1.84 22.40 72.20

1.93 22.40 77.20

2.03 24.90 82.20

*.

Add these resistance values to the available static resistance in the respective Blower Performance Tables.

†.

Deduct these resistance values from the available external static pressure shown in the respective Blower Performance Table.

‡.

The pressure drop through the economizer is greater for 100% outdoor air than for 100% return air. If the resistance of the return
air duct system is less than 0.25 IWG, the unit will deliver less CFM during full economizer operation.

38 Unitary Products Group

‡

127408-YIM-B-0606

TABLE 43: MOTOR SHEAVE DATUM

1VM50x7/8

(1-1/2, 2 & 3 HP Motor)

Turns Open

0 4.4 (111.7) 1 5.3 (134.6)

1/2 4.3 (109.2) 1-1/2 5.2 (132)

1 4.2 (106.6) 2 5.1 (129.5)

1-1/2 4.1 (104.1) 2-1/2 5.0 (127)

2 4.0 (101.6) 3 4.9 (124.4)

2-1/2 3.9 (99) 3-1/2 4.8 (121.9)

3 3.8 (96.5) 4 4.7 (119.3)

3-1/2 3.7 (94) 4-1/2 4.6 (116.8)

4 3.6 (91.4) 5 4.5 (114.3)

4-1/2 3.5 (88.9) 5-1/2 4.4 (111.7)

5 3.4 (86.3) 6 4.3 (109.2)

Datum Dia.

in.(mm.)

Turns Open

1VP56x1-1/8
(5 HP Motor)

Datum Dia.

in.(mm.)

Unitary Products Group 39

127408-YIM-B-0606

OPERATION

SEQUENCE OF OPERA TIONS OVERVIEW

For the Predator® series of units, the thermostat makes a cir­cuit between "R" and "Y1" for the first stage of cooling.

The call is passed to the Unit Control Board (UCB), which
then determines whether the requested operation is available
and, if so, which components to energize.

For gas heating, the UCB monitors the "W1" call but does not
handle the operation of the gas furnace. An ignition control
board controls the gas heater operation. For electric heat
units, the UCB passes the call to the electric heater. In both
cases, when the "W1" call is sensed, the indoor air blower is
energized following a specified heating delay.

If at any time a call for both heating and co oling are present,
the heating operation will be performed. If operating, the cool­ing system is halted as with a completion of a call for cooling.
Heating always takes priority.

COOLING SEQUENCE OF OPERATION

CONTINUOUS BLOWER

By setting the room thermostat fan switch to "ON," the supply
air blower will operate continuously.

INTERMITTENT BLOWER

With the room thermostat fan switch set to "AUTO" and the
system switch set to either the "AUTO" or "HEAT" settings,
the blower is energized whenever a cooling or heating opera­tion is requested. The blower is energized after any specified
delay associated with the operation.

When energized, the indoor blower has a minimum run ti me
of 30 seconds. Additionally, the indoor blower has a delay of
10 seconds between operations.

NO OUTDOOR AIR OPTIONS

When the thermostat calls for the first stage of cooling, the
low-voltage control circuit from “R” to “Y1” and “G” is com­pleted. The UCB energizes the economizer (if installed and

free cooling is available) or the first available compressor
and the condenser fans. For first stage cooling, compressor
#1 is energized. If compressor #1 is unavailable, compressor
#2 is energized. After completing the specified fan on delay
for cooling, the UCB will energize the blower motor.

When the thermostat calls for the second stage of cooling,
the low-voltage control circuit from “R” to “Y2” is completed.
The control board energizes the first available compressor. If
free cooling is being used for the first stage of cooling, com­pressor #1 is energized. If compressor #1 is active for first
stage cooling or the first compressor is locked-out, co mpres­sor #2 is energized. In free-cooling mode, if the cal l for the

second stage of cooling continues for 20 minutes, compres­sor #2 is energized, provided it has not been locked-out.

If there is an initial call for both stages of cooling, the UCB will
delay energizing compressor #2 by 30 seconds in order to
avoid a power rush.

Once the thermostat has been satisfied, it will de-energize Y1
and Y2. If the compressors have satisfied their minimum run
times, the compressors and condenser fans are de-ener­gized. Otherwise, the unit operates each cooling system until
the minimum run times for the compressors have been com­pleted. Upon the final compressor de-energizing, the blower
is stopped following the elapse of the fan off delay for cooling.

* To be available, a compressor must not be locked-out due
to a high or low-pressure switch or freezestat trip and the

Anti-Short Cycle Delay (ASCD) must have elapsed.
ECONOMIZER WITH SINGLE ENTHALPY SENSOR -

When the room thermostat calls for "first-stage" cooling, the
low voltage control circuit from "R" to "G" and "Y1" is com­pleted. The UCB energizes the blower motor (if the fan switch
on the room thermostat is set in the "AUTO" position) and
drives the economizer dampers from fully closed to their min­imum position. If the enthalpy of the outdoor air is below the
set point of the enthalpy controller (previously determined),
"Y1" energizes the economizer. The dampers will modulate to
maintain a constant supply air temperature as monitored by
the discharge air sensor. If the outdoor air enthalpy is above
the set point, "Y1" energizes compressor #1.

When the thermostat calls for "second-stage" cooling, the low
voltage control circuit from "R" to "Y2" is completed. The UCB
energizes the first available compressor. If the enthalpy of the
outdoor air is below the set point of the enthalpy controller
(i.e. first stage has energized the economizer), "Y2" will ener­gize compressor #1. If the outdoor air is above the set point,
"Y2" will energize compressor #2.

Once the thermostat has been satisfied, it will de-energize
“Y1” and “Y2”. If the compressors have satisfied their mini­mum run times, the compressors and condenser fans are de­energized. Otherwise, the unit operates each cooling system
until the minimum run times for the compressors have been
completed. Upon the final compressor de-energizing, the
blower is stopped following the elapse of the fan off delay for

*

cooling, and the economizer damper goes to the closed posi­tion. If the unit is in continues fan operation, the economizer
damper goes to the minimum position.

ECONOMIZER WITH DUAL ENTHALPY SENSORS -

The operation with the dual enthalpy sensors is identical to
the single sensor except that a second enthalpy sensor is
mounted in the return air. This return air sensor allows the
economizer to choose between outdoor air and return air,
whichever has the lowest enthalpy value, to provide maxi­mum operating efficiency.

40 Unitary Products Group

127408-YIM-B-0606

ECONOMIZER WITH POWER EXHAUST -

A unit equipped with an economizer (single or dual enthalpy)
and a power exhaust operates as specified above with one
addition. The power exhaust motor is energized 45 seconds
after the actuator position exceeds the exhaust fan set point
on the economizer control. When the power exhaust is oper­ating, the second stage of mechanical cooling will not oper­ate. As always, the "R" to "G" connection provides minimum
position but does not provide power exhaust operation.

MOTORIZED OUTDOOR AIR DAMPERS -

This system operation is the same as the units with no out­door air options with one exception. When the "R" to "G" cir­cuit is complete, the motorized damper drives open to a
position set by the thumbwheel on the damper motor. When
the "R" to "G" circuit is opened, the damper spring returns
fully closed.

COOLING OPERATION ERRORS

Each cooling system is monitored for operation outside of the
intended parameters. Errors are handled as described below.
All system errors override minimum run times for compressors.

HIGH-PRESSURE LIMIT SWITCH

During cooling operation, if a high-pressure limit switch
opens, the UCB will de-energize the associated compressor,
initiate the ASCD (Anti-short cycle delay), and, if the other
compressor is idle, stop the condenser fans. If the call for
cooling is still present at the conclusion of the ASCD, the
UCB will re-energize the halted compressor.

Should a high-pressure switch open three times within two
hours of operation, the UCB will lock-out the associated com­pressor and flash a code (see Table 52). If the other com­pressor is inactive, the condenser fans will be de-energized.

LOW-PRESSURE LIMIT SWITCH

Should a low-pressure switch open three times within one
hour of operation, the UCB will lock-out the associated com­pressor and flash a code (Table 52). If the other compressor
is inactive, the condenser fans will be de-energized.

FREEZESTAT

During cooling operation, if a freezestat opens, the UCB will
de-energize the associated compressor, initiate the ASCD,
and, if the other compressor is idle, stop the condenser fans.
If the call for cooling is still present at the conclusion of the
ASCD, the UCB will re-energize the halted compressor.

Should a freezestat open three times within two hours of
operation, the UCB will lock-out the associated compressor
and flash a code (Table 52). If the other compressor is inac­tive, the condenser fans will be de-energized.

LOW AMBIENT COOLING

To determine when to operate in low ambient mode, the UCB
has a pair of terminals connected to a temperature-activated
switch set at 45ºF. When the low ambient switch is closed
and the thermostat is calling for cooling, the UCB will operate
in the low ambient mode.

Low ambient mode operates the compressors in this manner:
10 minutes on, 5 minutes off. The indoor blower is operated
throughout the cycle. The 5-minute off period is necessary to
defrost the indoor coil.

Low ambient mode always begins with compressor opera­tion. Compressor minimum run time may extend the minutes
of compressor operation. The defrost cycle will begin immedi­ately following the elapse of the minimum run time.

When operating in low ambient mode, the UCB will not lock­out the compressors due to a freezestat trip. However, a
freezestat trip will de-energize the associated compressor. If
the call for cooling is still present at the end of the ASCD and
the freezestat has closed, the unit will resume operation.

The low-pressure limit switch is not monitored during the ini­tial 30 seconds of a cooling system's operation. For the fol­lowing 30 seconds, the UCB will monitor the low-pressure
switch to ensure it closes. If the low-pressure switch fails to
close after the 30-second monitoring phase, the UCB will de­energize the associated compressor, initiate the ASCD, and,
if the other compressor is idle, stop the condenser fans.

Once the low-pressure switch has been proven (closed dur­ing the 30-second monitor period described above), the UCB
will monitor the low-pressure limit switch for any openings. If
the low-pressure switch opens for greater than 5 seconds,
the UCB will de-energize the associated compressor, initiate
the ASCD, and, if the other compressor is idle, stop the con­denser fans.

If the call for cooling is still present at the conclusion of the
ASCD, the UCB will re-energize the halted compressor.

Unitary Products Group 41

SAFETY CONTROLS

The unit control board monitors the following inputs for each
cooling system:

1. A suction line freeze stat to protect against low evapora­tor temperatures due to a low airflow or a low return air
temperature, (opens at 26 ± 5 °F and resets at 38 ± 5°F).

2. A high-pressure switch to protect against excessive dis­charge pressures due to a blocked condenser coil or a
condenser motor failure, (opens at 405 ± 10 psig or 440
± 10 psig depending on unit model).

3. A low-pressure switch to protect against loss of refriger­ant charge, (opens at 22 ± 5 psig or 45 ± 5 psig).

The above pressure switches are hard-soldered to the unit.
The refrigeration systems are independently monitored and
controlled. On any fault, only the associated system will be

127408-YIM-B-0606

affected by any safety/preventive action. The other refrigerant
system will continue in operation unless it is affected by the
fault as well.

The unit control board monitors the temperature limit switch
of electric heat units and the temperature limit switch and the
gas valve of gas furnace units.

COMPRESSOR PROTECTION

In addition to the external pressure switches, the compressors
also have inherent (internal) protection. If there is an abnormal
temperature rise in a compressor, the protector will open to shut
down the compressor. The UCB incorporates features to mini­mize compressor wear and damage. An Anti-Short Cycle
Delay (ASCD) is utilized to prevent operation of a compressor
too soon after its previous run. Additionally, a minimum run time
is imposed any time a compressor is energized.

The ASCD is initiated on unit start-up and on any compressor
reset or lock-out.

FLASH CODES

The UCB will initiate a flash code associated with errors
within the system. Refer to UNIT CONTROL BOARD FLASH
CODES Table 52.

RESET

Remove the call for cooling, by raising thermostat setting
higher than the conditioned space temperature. This resets
any pressure or freezestat flash codes.

ELECTRIC HEATING SEQUENCE OF OPERATIONS

The following sequence describes the operation of the elec­tric heat section.

If the temperature limit opens three times within one hour, it
will lock-on the indoor blower motor and a flash code is initi­ated (See Table 52).

SAFETY CONTROLS

The UCB monitors the temperature limit switch of electric
heat units.

The control circuit includes the following safety controls:

LIMIT SWITCH (LS)

This control is located inside the heater compartment and is
set to open at the temperature indicated in the Electric Heat
Limit Setting Table 44. It resets automatically. The limit switch
operates when a high temperature condition, caused by inad­equate supply air flow occurs, thus shutting down the heater
and energizing the blower.

TABLE 44: ELECTRIC HEAT LIMIT SETTING

UNIT (TONS) VOLTAGE

10, 12.5
10, 12.5 24 150
10, 12.5 34 150
10, 12.5 54 130

380/415

FLASH CODES

The UCB will initiate a flash code associated with errors
within the system. Refer to UNIT CONTROL BOARD FLASH
CODES Table 52.

RESET

HEATERkWLIMIT SWITCH

OPENS °F

18 150

Two-stage heating:

Remove the call for heating by lowering the thermostat set­ting lower than the conditioned space temperature.This

a. Upon a call for first stage heat by the thermostat, the

resets any flash codes.

heater relay (RA) will be energized. After completing
the specified fan on delay for heating, the UCB will

ELECTRIC HEAT ANTICIPATOR SETPOINTS

energize the blower motor. If the second stage of
heat is required, heater relay (RB) will be energized.
After completing the specified fan on delay for heat­ing, the UCB will energize the blower motor.

b. The thermostat will cycle the electric heat to satisfy

the heating requirements of the conditioned space.

ELECTRIC HEAT OPERATION ERRORS

TEMPERA T URE LIMIT

It is important that the anticipator setpoint be correct. Too
high of a setting will result in longer heat cycles and a greater
temperature swing in the conditioned space. Reducing the
value below the correct setpoint will give shorter “ON” cycles
and may result in the lowering of the temperature within the
conditioned space. Refer to Table 45 for the required electric
heat anticipator setting.

TABLE 45: ELECTRIC HEAT ANTICIPATOR

SETPOINTS

If the UCB senses zero volts from the high temperature limit,
the indoor blower motor is immediately energized.

This limit is monitored regardless of unit operation status, i.e.
the limit is monitored at all times.

W1 W2

0.13 0.1

SETTING, AMPS

42 Unitary Products Group

127408-YIM-B-0606

GAS HEATING SEQUENCE OF OPERATIONS

When the thermostat calls for the first stage of heating, the
low-voltage control circuit from “R” to “W1” is completed. A
call for heat passes through the UCB to the Ignition Control
Board (ICB). The UCB monitors the “W1” call and acts upon
any call for heat by monitoring the Gas Valve (GV). Once
voltage has been sensed at the GV, the UCB will initiate the
fan on delay for heating, energizing the indoor blower the
specified delay has elapsed.

When the thermostat has been satisfied, heating calls are
ceased. The GV is immediately closed. The blower is de­energized after the fan off delay for heating has elapsed. The
draft motor performs a 30-second post purge.

IGNITION CONTROL BOARD

FIRST STAGE OF HEATIN G

When the ICB receives a call for first stage of heating, “W1,” the
draft motor is energized. Once the draft motor has been proven,
a 30-second purge is initiated. At the end of the purge, the GV
is opened, and the spark ignitor is energized for 10 seconds.
The ICB then checks for the presence of flame. If flame is
detected, the ICB enters a flame stabilization period. If flame
was not detected, the GV closes, and a retry operation begins.

During the flame stabilization period, a loss of the flame for 2
seconds will cause the GV to close and the retry operation to
begin. After the flame stabilization period, a loss of flame for
3/4 second will cause the GV to close and the retry operation
to begin.

RECYCLE OPERATION

When a flame is lost after the flame stabilization period, a
recycle operation occurs. If the unit fails after five recycle
attempts, the furnace is locked-out for one hour.

GAS HEATING OPERATION ERRORS

LOCK-OUT

A one-hour lockout occurs following three retries or five recy­cles. During the one-hour lockout, flame detection, limi t con­ditions, and main valves are tested. Any improper results will
cause the appropriate action to occur. Recycling the low volt­age power cancels the lock-out.

TEMPERATURE LIMIT

If the UCB senses zero volts from the high temperature limit,
the indoor blower motor is immediately energized. When the
UCB again senses 24 volts from the temperature limit, the
draft motor will perform a 15-second post-purge and the
indoor blower will be de-energized following the elapse of the
fan off delay for heating.

This limit is monitored regardless of unit operation status, i.e.
this limit is monitored at all times.

If the temperature limit opens three times wi thin one hour, it
will lock-on the indoor blower motor and flash code is initiated
(See Table 52).

FLAME SENSE

At the conclusion of the flame stabilization period, the ICB will
operate the gas heat in high fire for an additional 60 seconds
(for a total for 120 seconds of high fire operation). After this
60 seconds, the ICB will then use the call for the second
stage of heat to control second stage operation of the GV.

When “W1” is satisfied, both valves are closed.

SECOND STAGE OF HEATING

When the ICB receives a call for the second stage of heating,
“W2,” the ICB conducts a complete first stage ignition
sequence. If this sequence is satisfied, the second main
valve of the GV is opened.

When “W2” is satisfied, the second main valve is closed.

RETRY OPERATION

When a flame is lost or is not detected during an attempt to
achieve ignition, a retry operation occurs. A 30-second pu rg e
is performed between ignition attempts.

If the unit fails after three ignition attempts, the furnace is
locked-out for one hour. The furnace is monitored during this
one-hour period for unsafe conditions.

Flame sensing occurs at all times. If “W1” is not present and
a flame is sensed for 2 seconds, the draft motor is energized
and the GV is kept off. The ICB halts any operation until a
flame is not detected. Once the flame detection is lost, the
ICB performs a post-purge. Normal operation is allowed con­currently with the purge (i.e. this purge can be considered the
purge associated with a call for “W1”).

If “W1” is present, a flame is sensed, but the GV is not ener­gized, the draft motor is energized until the flame detection is
lost. Normal operation is now allowed.

The flame detection circuitry continually tests itself. If the ICB
finds the flame detection circuitry to be faulty, the ICB will not
permit an ignition sequence and the draft motor is energized.
If this failure should occur during an ignition cycle the failure
is counted as a recycle.

GAS VALVE

The UCB and ICB continuously monitor the GV.
If the ICB senses voltage at the GV when not requested, the

ICB will energize the draft motor. The ICB will not operate the
furnace until voltage is no longer sensed at the GV. The draft
motor is stopped when voltage is not sensed at the GV.

Unitary Products Group 43

127408-YIM-B-0606

Any time the UCB senses voltage at the GV without a call for
heat for a continuous five-minute period, the UCB will lock-on
the indoor blower and a flash code is initiated (Table 52).
When voltage is no longer sensed at the GV , the UCB will de­energize the indoor blower following the e lapse of the fan off
delay for heating.

If voltage has been sensed at the GV for at least 15 seconds
during the fan on delay for heating and GV voltage or “W1” is
lost, the indoor blower is forced on for the length of the fan off
delay for heating.

During a call for heat, if the UCB does not sense voltage at
the GV for a continuous five-minute period the UCB wil l ini­tiate a flash code (Table 52). The indoor blower motor will not
be locked-on while there is no GV voltage.

SAFETY CONTROLS

The UCB monitors the temperature limit switch of electric
heat units.

The control circuit includes the following safety controls:

LIMIT SWITCH (LS)

This control is located inside the heater compartment and is
set to open at the temperature indicated in the Electric Heat
Limit Setting Table 44. It resets automatically. The limit switch
operates when a high temperature condition, caused by inad­equate supply air flow occurs, thus shutting down the heater
and energizing the blower.

AUXILIARY LIMIT SWITCH (ALS)

This control is located inside the supply air compartment and
is set to open at the temperature indicated in the Gas Heat
Limit Control Settings Table 46. It resets manually. The limit
switch operates when a high temperature condition, caused
by inadequate supply air flow occurs, thus shutting down the
heater and energizing the blower.

The auxiliary limit switch is wired in series with the limit
switch. As such, the UCB cannot distinguish the auxiliary limit
and the gas heat limit switch operation except the auxiliary is
manual reset. Consequently, the control will respond in the
same manner as outlined above under “Limit Switch”.

PRESSURE SWITCH (PS)

Once the draft motor has reached full speed and closes the
pressure switch during a normal ignition sequence, if the
pressure sw opens for 2 seconds, the GV will be de-ener­gized, the ignition cycle is aborted, and the ICB flashes the
appropriate code. See Table 53 Ignition Control Flash Codes.
The draft motor is energized until the pressure switch closes
or “W1” is lost.

ROLLOUT SWITCH (ROS)

The rollout switch is wired in series with the pressure switch.
As such, the ICB cannot distinguish the rollout switch opera­tion from that of the pressure switch.

Consequently, the control will only respond in the same man­ner as outlined above under “Pressure Switch”. An open roll­out will inhibit the gas valve from actuating.

INTERNAL MICROPROCESSOR FAILURE

If the ICB detects an internal failure, it will cease all outputs,
ignore inputs, and display the proper flash code for control
replacement. The ICB remains in this condition until replaced.

FLASH CODES

The UCB will initiate a flash code associated with errors
within the system. Refer to UNIT CONTROL BOARD FLASH
CODES Table 52.

RESETS

Remove the call for heating by lowering the thermostat set­ting lower than the conditioned space temperature. This
resets any flash codes.

GAS HEA T ANTICIPATOR SETPOINTS

It is important that the anticipator setpoint be correct. Too
high of a setting will result in longer heat cycles and a greater
temperature swing in the conditioned space. Reducing the
value below the correct setpoint will give shorter “ON cycles
and may result in the lowering of the temperature within the
conditioned space. Refer to Table 47 for the required gas
heat anticipator setting.

TABLE 46: GAS HEAT LIMIT SETTINGS

Unit Main Limit Setting

Size Opt. Natural Gas LPG

DM090

DM120 15
DM150 15

*.

Rollout = 300°F (148.9°C), Auxiliary Limit = 200°F (93.3°C)

10
15

165°F (73.9°C) 175°F (79.4°C)
165°F (73.9°C) 185°F (85°C)
195°F (90.5°C) 195°F (90.5°C)
195°F (90.5°C) 195°F (90.5°C)

*

The ICB monitors the Pressure and Rollout switches of gas
heat units.

The control circuit includes the following safety controls:

TABLE 47: GAS HEAT ANTICIPATOR SETPOINTS

SETTING, AMPS

W1 W2

0.65 0.1

H E A T E X C H A N G E R T U B E

G A S
S U P P L Y

B U R N E R

P I P E

B U R N E R B R A C K E T

I G N I T O R

B U R N E R F L A M E

( B L U E O N L Y )

FIGURE 28 - TYPICAL FLAME

44 Unitary Products Group

127408-YIM-B-0606

START-UP (COOLING)

PRESTART CHECK LIST

After installation has been completed:

1. Check the electrical supply voltage being suppl ied. Be
sure that it is the same as listed on the unit nameplate.

2. Set the room thermostat to the off position.

3. Turn unit electrical power on.

4. Set the room thermostat fan switch to on.

5. Check indoor blower rotation.

• If blower rotation is in the wrong direction. Refer to

Phasing Section in general information section.

• Check blower drive belt tension.

6. Check the unit supply air (CFM).

7. Measure evaporator fan motor's amp draw.

8. Set the room thermostat fan switch to off.

9. Turn unit electrical power off.

OPERATING INSTRUCTIONS

1. Turn unit electrical power on.

OPERATING INSTRUCTIONS

This furnace is equipped with an automatic re-ignition
system. DO NOT attempt to manually light the pilot.

LIGHTING THE MAIN BURNERS

1. Turn “OFF” electric power to unit.

2. Turn room thermostat to lowest setting.

3. Turn gas valve counter-clockwise to “ON” position (see 19).

4. Turn “ON” electric power to unit.

5. If thermostat set temperature is above room tempera­ture, the main burners will ignite. If a second stage of
heat is called for, the main burners for second stage heat
will ignite for the second stage heat.

POST START CHECKLIST

After the entire control circuit has been energized and the
heating section is operating, make the following checks:

1. Check for gas leaks in the unit piping as well as the sup­ply piping.

NOTE: Prior to each cooling season, the crankcase heaters

must be energized at least 10 hours before the sys­tem is put into operation.

2. Set the room thermostat setting to lower than the room
temperature.

3. First stage compressors will energize after the built-in
time delay (five minutes).

4. The second stage of the thermostat will energize second
stage compressor if needed.

POST START CHECK LIST

1. Verify proper system pressures for both circuits.

2. Measure the temperature drop across the evaporator
coil.

START-UP (GAS HEAT)

PRE-START CHECK LIST

Complete the following checks before starting the unit.

1. Check the type of gas being supplied. Be sure that it is
the same as listed on the unit nameplate.

2. Make sure that the vent outlet and combustion air inlet
are free of any debris or obstruction.

FIRE OR EXPLOSION HAZARD
Failure to follow the safety warning exactly could

result in serious injury, death or property damage.
Never test for gas leaks with an open flame. Use a

commercially available soap solution made specifi­cally for the detection of leaks to check all connec­tions. A fire or explosion may result causing property
damage, personal injury or loss of life.

2. Check for correct manifold gas pressures. (See ’CHECK­ING GAS INPUT’.)

3. Check the supply gas pressure. It must be within the lim­its shown on the rating nameplate. Supply pressure
should be checked with all gas appliances in the building
at full fire. At no time should the standby gas pressure
exceed 13 in. or the operating pressure drop below 5.0 in
for natural gas units. If gas pressure is outside these
limits, contact the local gas utility or propane supplier for
corrective action.

SHUT DOWN

1. Set the thermostat to the lowest temperature setting.

2. Turn “OFF” all electric power to unit.

Unitary Products Group 45

127408-YIM-B-0606

3. Open gas heat access panel.

4. Turn gas valve clockwise to “OFF” position (See Figure 29).

MANIFOLD GAS PRESSURE ADJUSTMENT

This gas furnace has two heat stages. Therefore, the gas
valve has two adjustment screws located under a plas tic pr o­tective cover. The second stage (100% input) adjustment
screw is adjacent to the “HI” marking on the valve and the
first stage (60% input) adjustment screw is located adjacent
to the “LO” marking on the valve (See Figure 29).

Manifold pressure adjustment procedure.
Adjust second stage (100% input) pressure first, then adjust

first stage (60% input) pressure.

1. Turn off all power to the unit.

2. Using the outlet pressure port on the gas valve, connect
a manometer to monitor the manifold pressure.

3. Remove plastic cap covering HI and LO pressure adjust­ment screws.

4. Turn on power to the unit.

5. Set thermostat to call for second stage heat and start fur­nace.

6. If necessary, using a screwdriver, turn the

second stage
adjustment screw (adjacent to the “HI” marking on the
valve) clockwise to increase manifold pressure or coun­terclockwise to decrease manifold pressure. Be sure
not to over-fire the unit on second stage.

7. After the high manifold pressure has been checked,
adjust the thermostat to call for first stage heat.

8. If necessary, using a screwdriver, turn the first stage
adjustment screw (adjacent to the “LO” marking on the
valve) clockwise to increase manifold pressure or
counterclockwise to decrease manifold pressure. Be
sure not to under-fire the unit on first stage.

9. Once pressure has been checked, replace the plastic
cap covering the HI and LO pressure adjustment screws.

NOTE: When using natural gas, the manifold pressure for

second stage (100% input) should be 3.5 IWG ±

0.3. The manifold pressure for first stage (60%
input) when using natural gas should be 1.5 IWG ±

0.3.

TABLE 48: GAS HEAT STAGES

1st Stage

Input (60%)

Btuh

# of Burner Tubes

4
6

2nd Stage

Input (100%

Btuh)

120,000 72,000
175,000 105,000

CHECKING GAS INPUT

NATURAL GAS

This unit has two stages of gas heat. The first stage is 60% of
the full fire input and is considered the minimum input for the
furnace. The intended input for each furnace is shown in the
table below. The following Table applies to units operating on
60 Hz power only.

To determine the rate of gas flow (Second Stage).

1. Turn off all other gas appliances connected to the gas
meter.

2. Turn on the furnace and make sure the thermostat is
calling for Second stage (100% input) heat.

3. Measure the time needed for one revolution of the hand
on the smallest dial on the meter. A typical gas meter
has a 1/2 or a 1 cubic foot test dial.

4. Using the number of seconds it takes for one revolution
of the dial, calculate the cubic feet of gas consumed per
hour. (See example below).

5. If necessary, adjust the high pressure regulator as
discussed in the section “Manifold Gas Pressure
Adjustment”. Be sure not to over-fire the furnace on
Second stage. If in doubt, it is better to leave the Second
stage of the furnace slightly under-fired. Repeat Steps 1-

5.

To determine the rate of gas flow (First Stage)

1. Turn off all other gas appliances connected to the gas
meter.

2. Turn on the furnace and make sure the thermostat is
calling for first stage (60% input) heat.

3. Even when the thermostat is calling for first stage heat,
the unit will light on second stage and will run on Second
stage for 1 minute. Allow this one-minute time period to
expire and be certain the unit is running on first stage.

4. Measure the time needed for one revolution of the hand
on the smallest dial on the meter. A typical gas meter
has a 1/2 or a 1 cubic foot test dial.

5. Using the number of seconds it takes for one revolution
of the dial, calculate the cubic feet of gas consumed per
hour (See example below).

6. If necessary, adjust the low pressure regulator as dis­cussed in the section “Manifold Gas Pressure Adjust­ment”. Be sure not to under-fire the furnace on first
stage. If in doubt, it is better to leave the first stage of the
furnace slightly over-fired (greater than 60% input).
Repeat Steps 1-6.

46 Unitary Products Group

127408-YIM-B-0606

TABLE 49: GAS RATE CUBIC FEET PER HOUR

Seconds

for One

Rev.

10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
52
54
56
58
60

NOTE: To find the Btu input, multiply the number of cubic

feet of gas consumed per hour by the Btu content of
the gas in your particular locality (contact your gas
company for this information as it varies widely from

area to area).
EXAMPLE:
By actual measurement, it takes 19 seconds for the hand on

a 1 cubic foot dial to make a revolution with a 192,000 Btuh
furnace running. To determine rotations per minute, divide 60
by 19 = 3.16. To calculate rotations per hour, multiply 3.16 •
60 = 189.6. Multiply 189.6 • 1 (0.5 if using a 1/2 cubic foot
dial) = 189.6. Multiply 189.6 • (the Btu rating of the gas). For
this example, assume the gas has a Btu rating of 1050

3

. The result of 199,000 Btuh is within 5% of the

Btu/ft.
192,000 Btuh rating of the furnace.

Size of Test Dial

1/2 cu. ft. 1 cu. ft.

180 360
150 300
129 257
113 225
100 200

90 180
82 164
75 150
69 138
64 129
60 120
56 113
53 106
50 100
47 95
45 90
43 86
41 82
39 78
37 75
36 72
35 69
34 67
32 64
31 62
30 60

ADJUSTMENT OF TEMPERATURE RISE

The temperature rise (the difference of temperature between
the return air and the heated air from the furnace) must lie
within the range shown on the CSA rating plate and the data
in Table 47.

After the temperature rise has been determined, the CFM can
be calculated as follows:

0.8

CFM Btu Input

-----------------------------

•=

1.08 Δ°F⋅()

After about 20 minutes of operation, determine the furnace
temperature rise. Take readings of both the return air and the
heated air in the ducts (about 6 feet from the furnace) where
they will not be affected by radiant heat. Increase the blower
CFM to decrease the temperature rise; decrease the blower
CFM to increase the rise (See ’SUPPLY AIR DRIVE
ADJUSTMENT’).

NOTE: Each gas heat exchanger size has a minimum

allowable CFM. Below this CFM, the limit will open.

BURNERS/ORIFICES INSPECTION/SERVICING

Before checking or changing burners, pilot or orifices,
CLOSE MAIN MANUAL SHUT-OFF VALVE AND SHUT OFF
ALL POWER TO THE UNIT.

1. Open the union fitting just upstream of the unit gas valve
and downstream from the main manual shut-off valve in
the gas supply line.

2. Remove the screws holding each end of the manifold to
the manifold supports.

3. Disconnect wiring to the gas valves and spark igniter(s).
Remove the manifold & gas valve assembly. Orifices can
now be inspected and/or replaced.

To service burners, complete step 4.

4. Remove the heat shield on top of the manifold supports.
Burners are now accessible for inspection and/or
replacement.

NOTE: Reverse the above procedure to replace the assem-

blies.

Make sure that burners are level and seat at the rear of the
gas orifice.

Unitary Products Group 47

I N L E T

P R E S S U R E

T A P

H I G H & L O W G A S A D J U S T M E N T

L O

H I

O N

O F F

M A T E - N - L O C K

C O N N E C T O R S

M V

C

H I

127408-YIM-B-0606

O U T L E T

P R E S S U R E

T A P

FIGURE 29 - TYPICAL GAS VALVE

CHARGING THE UNIT

These units should be charged using the superheat method.
Super heat charging data is shown in Tables 50 thru 51.

When charging each system, superheat data should be taken
at the compressor inlet.

TABLE 50: 7.5 TON SUPERHEAT CHARGING

Superheat at Compressor Suction (°F)

Outdoor

Te mp ( °F)

55 57 59 6 1 63 65 67 69 71 73 75

65 7.8 10.9 14.0 17.1 20.1 23.2 26.3 27.1 28.0 28.8 29.7
70 6.5 9.4 12.3 15.2 18.1 21.0 23.9 25.0 26.2 27.3 28.5
75 5.1 7.9 10.6 13.3 16.0 18.7 21.4 22.9 24.4 25.8 27.3
80 - 6.3 8.8 11.4 13.9 16.4 19.0 20.8 22.6 24.4 26.2
85 - - 7.1 9.5 11.8 14.2 16.5 18.6 20.7 22.9 25.0
90 - - - 6.7 8.8 10.9 13.1 15.9 18.7 21.6 24.4

95 - - - - 5.8 7.7 9.6 13.2 16.7 20.3 23.8
100 - - - - - 5.8 7.2 11.0 14.8 18.5 22.3
105 -------8.8 12.8 16.8 20.8
110 -------6.6 10.8 15.1 19.3
115 --------8.9 13.3 17.8

Airflow = 3000 CFM

Indoor WB Temp (°F)

48 Unitary Products Group

127408-YIM-B-0606

TABLE 51: 10 TON SUPERHEAT CHARGING

Superheat at Compressor Suction (°F)

Outdoor

Temp (°F)

55 57 59 61 63 65 67 69 71 73 75

65
70
75
80
85
90

95
100
105

110
115

26.8 27.4 28.0 28.6 29.3 29.9 30.5 31.1 31.7 32.4 33.0

25.3 26.0 26.6 27.3 28.0 28.7 29.3 30.0 30.7 31.4 32.0

23.8 24.5 25.3 26.0 26.7 27.5 28.2 28.9 29.6 30.4 31.1

22.8 23.5 24.3 25.0 25.8 26.5 27.3 28.0 28.8 29.5 30.3

21.8 22.5 23.3 24.1 24.8 25.6 26.4 27.1 27.9 28.7 29.4

20.2 21.0 21.8 22.5 23.3 24.1 24.9 25.6 26.4 27.2 28.0

18.7 19.5 20.2 21.0 21.8 22.6 23.4 24.1 24.9 25.7 26.5

17.1 17.9 18.6 19.4 20.2 20.9 21.7 22.5 23.2 24.0 24.8

15.5 16.3 17.1 17.8 18.6 19.3 20.1 20.8 21.6 22.3 23.1

14.1 14.9 15.6 16.4 17.2 18.0 18.7 19.5 20.3 21.1 21.8

12.6 13.4 14.2 15.0 15.8 16.6 17.4 18.2 19.0 19.8 20.6

12-1/2 ton unit uses TXV. Charge the unit to 10° subcooling.

Indoor WB Temp (°F)

Airflow = 4000 CFM

Unitary Products Group 49

127408-YIM-B-0606

TROUBLESHOOTING

Troubleshooting of components may require open­ing the electrical control box with the power con­nected to the unit. Use extreme care when
working with live circuits! Check the unit name­plate for the correct line voltage and set the voltme­ter to the correct range before making any
connections with line terminals.

When not necessary, shut off all electric power to the
unit prior to any of the following maintenance proce­dures so as to prevent personal injury.

Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and dan­gerous operation which could cause injury to person
and/or damage unit components. Verify proper oper­ation after servicing.

PREDATOR® FLASH CODES

Various flash codes are utilized by the unit control board
(UCB) to aid in troubleshooting. Flash codes are
distinguished by the short on and off cycle used
(approximately 200ms on and 200ms off). To show normal
operation, the control board flashes a 1 second on, 1 second
off "heartbeat" during normal operation. This is to verify that
the UCB is functioning correctly. Do not confuse this with an
error flash code. To prevent confusion, a 1-flash, flash code
is not used.

Alarm condition codes are flashed on the UCB lower left Red
LED, See Figure 30. While the alarm code is being flashed, it
will also be shown by the other LEDs: lit continuously while
the alarm is being flashed. The total of the continuously lit
LEDs equates to the number of flashes, and is shown in the
table. Pressing and releasing the LAST ERROR button on
the UCB can check the alarm history. The UCB will cycle
through the last five (5) alarms, most recent to oldest,
separating each alarm flash code by approximately 2
seconds. In all cases, a flashing Green LED will be used to
indicate non-alarm condition.

In some cases, it may be necessary to "zero" the ASCD for
the compressors in order to perform troubleshooting. To reset
all ASCDs for one cycle, press and release the UCB TEST/
RESET button once.

Flash codes that do and do not represent alarms are li ste d in
Table 52.

TABLE 52: UNIT CONTROL BOARD FLASH CODES

GREEN

FLASH CODE DESCRIPTION

On Steady This is a Control Failure - - - - -

1 Flash Not Applicable - - - - ­2 Flashes
3 Flashes HPS1 Compressor Lockout Off Off Off On On

4 Flashes HPS2 Compressor Lockout Off Off On Off Off
5 Flashes LPS1 Compressor Lockout Off Off On Off On
6 Flashes LPS2 Compressor Lockout Off Off On On Off
7 Flashes FS1 Compressor Lockout Off Off On On On
8 Flashes FS2 Compressor Lockout Off On Off Off Off
9 Flashes Ignition Control Locked Out / Ignition Control Failure Off On Off Off On

10 Flashes
11 Flashes

12 Flashes Unit Locked Out due to Fan Overload Switch Failure Off On On Off Off
13 Flashes
14 Flashes EEPROM Storage Failure Off On On On Off

OFF No Power or Control Failure Off Off Off Off Off

*.

Non-alarm condition.

Control waiting ASCD

Compressors Locked Out on Low Outdoor Air Temperature
Compressors locked out because the Economizer is using free

1

Cooling

Compressor Held Off due to Low Voltage

*

1

1

LED

16

Flashing Off Off On Off

Flashing On Off On Off
Flashing On Off On On

Flashing On On Off On

RED

LED

8

RED

LED

4

RED
LED

2

RED
LED

1

50 Unitary Products Group

127408-YIM-B-0606

TABLE 53: IGNITION CONTROL FLASH CODES

FLASHES FAULT CONDITIONS CHECK

STEADY ON

HEARTBEAT

1

2

3

4

5

6

STEADY OFF

Control Failure Control
Normal Operation
Not Applicable
Pressure Switch

Stuck Closed
Pressure Switch Failed

To Close

Limit Switch Open

Flame Present With Gas
Off First Stage Gas Valve
Energized With W1 Off
Second Stage Gas Valve
Energized With First
Stage
Gas Valve Off

Ignition Lockout

No Power Or Control
Failure

Pressure Switch

Venter Pressure Switch
Vent Blocked

Main Limit
AUX Limit

Gas Valve

Gas Flow
Gas Pressure
Gas Valve
Flame Sensor

24VAC or Control

Check

Alarm

History

Reset All
ASCDs for
One Cycle

Non Alarm

Condition Green

LED Flashing

Current Alarm

Flashed

Red LED

FIGURE 30: UNIT CONTROL BOARD

Unitary Products Group 51

127408-YIM-B-0606

Monitor

Monitored

Systems

Problem?

Trip/Failure

Turn off ID

Blower Motor

No No

Yes

Yes

No

Programming?

Yes

Program

Unit

Control

Board

No

Fan on

>30 secs?

Yes

Lossof Call

for ID Blower?

Call for

Heating?

Call for

Heat

Energize ID

Blower Motor

No

Fan off

>10 secs?

No

Call for

ID Blower?

No

Yes

Yes

Yes

Loss of
Call for

Heating?

Call for

Cooling?

No

Loss of Call

for Cooling?

Yes

No

Yes

No

Yes

Heat Off

Call for 2nd

Stage

Cooling

No

First

Stage?

Yes

Call for 1st

Stage

Cooling

Cool Off

FIGURE 31 - BASIC TROUBLESHOOTING FLOWCHART

Power to

Unit

Call for

heat?

No

Initialize ASCD

Montior

Yes

Voltage @

Gas Valve?

No

Energize ID

Blower

Yes

FIGURE 32 - POWER ON FLOW CHART

52 Unitary Products Group

127408-YIM-B-0606

T r i p / F a i l u r e

L o s s o f

L S I n p u t

Y e s

E n e r g i z e b l o w e r :
i n c r e a s e i n c i d e n t

v a l u e b y 1

N o N o N o N o

H P
S w i t c h
O p e n

1

Y e s Y e s Y e s

T u r n o f f

c o m p r e s s o r ;

i n i t i a t e A S C D ;

i n c r e a s e i n c i d e n t

v a l v e b y 1

L P

S w i t c h O p e n

2

> 5 S e c s

T u r n o f f

C o m p r e s s o r ,

i n i t i a t e A S C D ;

i n c r e a s e i n c i d e n t

v a l u e b y 1

N o

I n c i d e n t

v a l u e > = 3 ?

L S i n p u t

r e g a i n e d ?

N o

N o

I n c i d e n t

v a l u e > = 3

N o

I n c i d e n t

v a l u e > = 3

N o

Y e s Y e s Y e s Y e s Y e s

L o c k o n b l o w e r ;

f l a g a l a r m

L o a d F o f f D

L o c k - o u t

c o m p r e s s o r , f l a g

a l a r m

L o c k - o u t

c o m p r e s s o r , f l a g

a l a r m

M o n i t o r

L o s s o f

F O S i n p u t

> 5 S e c s ?

Y e s

T u r n o f f f a n

c o m p r e s s o r &

c o n d e n s e r f a n s ;

i n i t i a t e A S C D

N o N o N o

C a l l f o r

H e a t w / o u t G V

v o l t a g e ?

Y e s

N o

v o l t a g e > 5

m i n ?

F l a g A l a r m

Y e s

G V

v o l t a g e

w / o u t c a l l f o r

h e a t ?

F r e e z e s t a t

1

O p e n ?

T u r n o f f

c o m p r e s s o r ,

i n i t i a t e A S C D ;

i n c r e a s e i n c i d e n t

v a l u e b y 1

I n c i d e n t

v a l u e > = 3

L o c k - o u t

c o m p r e s s o r , t u r n

o f f I D b l o w e r , t u r n

o f f c o n d e n s e r

f a n s , f l a g a l a r m

G V v o l t a g e

Y e s

F l a g a l a r m , l o c k

o n I D b l o w e r

> 5 m i n ?

N o

N o

I n c i d e n t

v a l u e > = 3

F O S i n p u t

N o

r e g a i n e d ?

N o

Y e s Y e s Y e s

L o c k - o u t

c o m p r e s s o r s , t u r n

o f f I D b l o w e r , t u r n

o f f c o n d e n s e r

f a n s , f l a g a l a r m

I n c r e a s e i n c i d e n t

v a l u e b y 1

N o

F O S i n p u t > 1 5

m i n u t e s ?

F l a g a l a r m , t u r n o n

X l i n e

Y e s

b l o w e r , l o a d ' F a n

O f f D e l a y ' f o r

L o s s o f G V

V o l t a g e ?

N o

E n e r g i z e I D

h e a t i n g

M o n i t o r

1 T h e c o n t r o l b o a r d o n l y m o n i t o r s t h e i n p u t w h e n t h e c o m p r e s s o r r e a l l y i s e n e r g i z e d .
2 T h e l o w - p r e s s u r
a n d a d d i t i o n a l 3 0 s e c o n d s , t h e c o n
l o n g e r h a n d l e s t h e l o w - p r e s s u r e s w i t c h d i f f e r e n t l y t h a n o t h e

e s w i t c h i s n o t m o n i t o r e d f o r t h e f i r s t 3 0 s e c o n d s o f c o m p r e s s o r a c t i v i t y . T h e c o n t r o l b o a r d t h e n m o n i t o r s t h e s w i t c h t o e n s u r e i t c l o s e s . I f t h e s w i t c h r e m a i n s o p e n

t r o l b o a r d t u r n s o f f t h e a s s o c i a t e d c o m p r e s s o r a n d i n i t i a t e s t h e A S C D . O n c e i t h a s c l o s e d d u r i n g t h e s t a r t u p p e r i o d , t h e c o n t r o l b o a r d n o

r i n p u t s .

FIGURE 33 - TRIP FAILURE FLOW CHART

Unitary Products Group 53

127408-YIM-B-0606

COOLING TROUBLESHOOTING GUIDE

On calls for cooling, if the compressors are operating but the
supply air blower motor does not energize after a short delay
(the room thermostat fan switch is in the “AUTO” position):

1. Turn the thermostat fan switch to the ON position. If the
supply air blower motor does not energize, go to Step 3.

2. If the blower motor runs with the fan switch in the ON
position but will not run after the first compressor has
energized when the fan switch is in the AUTO position,
check the room thermostat for contact between R and G
in the AUTO position during calls for cooling.

3. If the supply air blower motor does not energize when
the fan switch is set to ON, check that line voltage is
being supplied to the contacts of the M3, contactor, and
that the contactor is pulled in. Check for loose wiring
between the contactor and the supply air blower motor.

4. If M3 is pulled in and voltage is supplied to M3, lightly
touch the supply air blower motor housing. If it is hot, the
motor may be off on internal protection. Cancel any
thermostat calls and set the fan switch to AUTO. Wait for
the internal overload to reset. Test again when cool.

5. If M3 is not pulled in, check for 24 volts at the M3 coil. If
24 volts are present at M3 but M3 is not pulled in,
replace the contacto r.

6. Failing the above, if there is line voltage supplied at M3,
M3 is pulled in, and the supply air blower motor still does
not operate, replace the motor.

7. If 24 volts is not present at M3, check that 24 volts is
present at the UCB supply air blower motor terminal,
“FAN”. If 24 volts is present at the FAN, check for loose
wiring between the UCB and M3.

8. If 24 volts is not present at the “FAN” terminal, check for
24 volts from the room thermostat. If 24 volts are not
present from the room thermostat, check for the following:

a. Proper operation of the room thermostat (contact

between R and G with the fan switch in the ON posi­tion and in the AUTO position during operation
calls).

b. Proper wiring between the ro om thermostat and the

UCB, and

c. Loose wiring from the room thermostat to the UCB

9. If 24 volts is present at the room thermostat but not at the
UCB, check for proper wiring between the thermostat and
the UCB, i.e. that the thermostat G terminal is connected
to the G terminal of the UCB, and for loose wiring.

10. If the thermostat and UCB are properly wired, replace
the UCB.

On calls for cooling, the supply air blower motor is operatin g
but compressor #1 is not (the room thermostat fan switch is in
the “AUTO” position):

1. If installed, check the position of the economizer blades.
If the blades are open, the economizer is providing free
cooling and the compressors will not immediately oper­ate. If both stages of cooling are requested simulta­neously and the economizer provides free cooling,
following a short delay compressor #1 will be energized
unless it is locked out. If compressor #1 is locked out,
compressor #2 is energized. Compressor #2 is always
energized in place of compressor #1 when compressor
#1 is requested but locked out.

2. If no economizer is installed or the economizer is not
opening to provide free cooling and compressor #1 does
not energize on a call for cooling, check for line voltage
at the compressor contactor, M1, and that the contactor
is pulled in. Check for loose wiring between the contac­tor and the compressor.

3. If M1 is pulled in and voltage is supplied at M1, lightly
touch the compressor housing. If it is hot, the compres­sor may be off on inherent protection. Cancel any calls
for cooling and wait for the internal overload to reset.
Test again when cool.

4. If M1 is not pulled in, check for 24 volts at the M1 coil. If
24 volts are present and M1 is not pulled in, replace the
contactor.

5. Failing the above, if voltage is supplied at M1 , M1 is
pulled in, and the compressor still does not operate,
replace the compressor.

6. If 24 volts is not present at M1, check for 24 volts at the
UCB terminal, C1. If 24 volts is present, check for loose
wiring between C1 and the compressor contactor.

7. If 24 volts is not present at the C1 terminal, check for 24
volts from the room thermostat at the UCB Y1 terminal. If
24 volts is not present from the room thermostat, check
for the following:

a. 24 volts at the thermostat Y1 terminal
b. Proper wiring between the ro om thermostat and the

UCB, i.e. Y1 to Y1, Y2 to Y2, and

c. Loose wiring from the room thermostat to the UCB

8. If 24 volts is present at the UCB Y1 terminal, the com­pressor may be out due to an open high-pressure switch,
low-pressure switch, or freezestat. Check for 24 volts at
the HPS1, LPS1, and FS1 terminals of the UCB. If a
switch has opened, there should be a voltage potential
between the UCB terminals, e.g. if LPS1 has opened,
there will be a 24-volt potential between the LPS1 termi­nals.

54 Unitary Products Group

127408-YIM-B-0606

9. If 24 volts is present at the UCB Y1 terminal and none of
the protection switches have opened, the UCB may have
locked out the compressor for repeat trips. The UCB
should be flashing an alarm code. If not, press and
release the ALARMS button on the UCB. The UCB will
flash the last five alarms on the LED. If the compressor is
locked out, cancel any call for cooling. This will reset any
compressor lock outs.

NOTE: While the above step will reset any lockouts, com-

pressor #1 may be held off for the ASCD. See the
next step.

10. If 24 volts is present at the UCB Y1 terminal and none of
the switches are open and the compressor is not locked
out, the UCB may have the compressor in an ASCD.
Check the LED for an indication of an ASCD cycle. The
ASCD should time out within 5 minutes. Press and
release the TEST button to reset all ASCDs.

11. If 24 volts is present at the UCB Y1 terminal and the
compressor is not out due to a protective switch trip,
repeat trip lock out, or ASCD, the economizer terminals
of the UCB may be improperly wired. Check for 24 volts
at the Y1 “OUT” terminal of the UCB. If 24 volts is
present, trace the wiring from Y1 “OUT” for incorrect wir­ing. If 24 volts is not present at the Y1 “OUT” terminal,
the UCB must be replaced.

12. For units without economizers: If 24 volts is present at
the Y1 OUT terminal, check for 24 volts at the Y1
“ECON” terminal. If 24 volts is not present, check for
loose wiring from the Y1 “OUT” terminal to the Mate-N­Lock plug, the jumper in the Mate-N-Lock plug, and in
the wiring from the Mate-N-Lock plug to the Y1 “ECON”
terminal.

13. For units with economizers: If 24 volts is present at the
Y1 “OUT” terminal, check for 24 volts at the Y1 “ECON”
terminal. If 24 volts is not present, check for loose wiring
from the Y1 “OUT” terminal to the Mate-N-Lock plug, a
poor connection between the UCB and economizer
Mate-N-Lock plugs, loose wiring from the Mate-N-Lock
plug to the economizer, back to the Mate-N-Lock plug,
and from the Mate-N-Lock plug to the Y1 “ECON” termi­nal. If nothing is found, the economizer control may have
faulted and is failing to return the 24-volt “call” to the Y1
“ECON” terminal even though the economizer is not pro­viding free cooling. T o test, disconnect the Mate-N-Locks
and jumper between the WHITE and YELLOW wires of
the UCB’s Mate-N-Lock plug. If compressor #1 ener­gizes, there is a fault in the economizer wiring or the
economizer control.

14. The UCB can be programmed to lock out compressor
operation during free cooling and in low ambient condi­tions. These options are not enabled by default. Local
distributors can test the UCB for this programming.

For units with factory installed economizers, the UCB is
programmed to lock out compressor operation when the
LAS set point is reached.

For units without factory installed or with field installed
economizers, the UCB allows compressor operation all
the time. This programming can be checked or changed
by the local distributor.

15. If none of the above corrected the error, test the integrity
of the UCB. Disconnect the C1 terminal wire and jumper
it to the Y1 terminal. DO NOT jump the Y1 to C1 termi­nals. If the compressor engages, the UCB has faulted.

16. If none of the above correct the error, replace the UCB.

On calls for the second stage of cooling, the supply air blower
motor and compressor #1 are operating but compressor #2 is
not (the room thermostat fan switch is in the “AUTO” position):

1. If installed, check the position of the economizer blades.
If the blades are open, the economizer is providing free
cooling. If the second stage of cooling is requested, fol­lowing a short delay, compressor #1 will be energized
unless it is locked out. Typically, compressor #2 is ener­gized only during free cooling if the call for the second
stage of cooling persists for 20 minutes.

2. Compressor #2 will not energize simultaneously with
compressor #1 if a call for both stages of cooling is
received. The UCB delays compressor #2 by 30 sec­onds to prevent a power surge. If after the delay com­pressor #2 does not energize on a second stage call for
cooling, check for line voltage at the compressor contac­tor, M2, and that the contactor is pulled in. Check for
loose wiring between the contactor and the compressor.

3. If M2 is pulled in and voltage is supplied at M2, lightly
touch the compressor housing. If it is hot, the compres­sor may be off on inherent protection. Cancel any calls
for cooling and wait for the internal overload to reset.
Test again when cool.

4. If M2 is not pulled in, check for 24 volts at the M2 coil. If
24 volts is present and M2 is not pulled in, replace the
contactor.

5. Failing the above, if voltage is supplied at M2, M2 is
pulled in, and the compressor still does not operate,
replace the compressor.

6. If 24 volts is not present at M2, check for 24 volts at the
UCB terminal, C2. If 24 volts are present, check for
loose wiring between C2 and the compressor contactor.

7. If 24 volts is not present at the C2 terminal, check for 24
volts from the room thermostat at the UCB Y2 terminal. If
24 volts is not present from the room thermostat, check
for the following:

a. 24 volts at the thermostat Y2 terminal
b. Proper wiring between the room thermostat and the

UCB, i.e. Y1 to Y1, Y2 to Y2, and

c. Loose wiring from the room thermostat to the UCB

8. If 24 volts is present at the UCB Y2 terminal, the com­pressor may be out due to an open high-pressure switch,

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127408-YIM-B-0606

low-pressure switch, or freezestat. Check for 24 volts at
the HPS2, LPS2, and FS2 terminals of the UCB. If a
switch has opened, there should be a voltage potential
between the UCB terminals, e.g. if LPS2 has opened,
there will be 24 volts of potential between the LPS2 ter­minals.

9. If 24 volts is present at the UCB Y2 terminal and none of
the protection switches have opened, the UCB may have
locked out the compressor for repeat trips. The UCB
should be flashing a code. If not, press and release the
ALARMS button on the UCB. The UCB will flash the last
five alarms on the LED. If the compressor is locked out,

remove any call for cooling at the thermostat or by dis­connecting the thermostat wiring at the Y2 UCB terminal.
This will reset any compressor lock outs.

NOTE: While the above step will reset any lock outs, com-

pressor #1 will be held off for the ASCD, and com­pressor #2 may be held off for a portion of the
ASCD. See the next step.

10. If 24 volts is present at the UCB Y2 terminal and none of
the switches are open and the compressor is not locked
out, the UCB may have the compressor in an ASCD.
Check the LED for an indication of an ASCD cycle. The
ASCD should time out within 5 minutes. Press and
release the TEST button to reset all ASCDs.

1 1. The UCB can be programmed to lock out compressor

operation during free cooling and in low ambient condi­tions. These options are not enabled by default. Local
distributors can test the UCB for this programming.

For units with factory installed economizers, the UCB is
programmed to lock out compressor operation when the
LAS set point is reached.

For units without factory installed or with field installed
economizers, the UCB allows compressor operation all
the time. This programming can be checked or changed
by the local distributor.

12. If none of the above corrected the error, test the integrity
of the UCB. Disconnect the C2 terminal wire and jumper
it to the Y2 terminal. DO NOT jump the Y2 to C2 termi­nals. If the compressor engages, the UCB has faulted.

13. If none of the above correct the error, replace the UCB.

On a call for cooling, the supply air blower motor and com­pressor #2 are operating but compressor #1 is not (the room
thermostat fan switch is in the “AUTO” position):

1. Compressor #2 is energized in place of compressor #1
when compressor #1 is unavailable for cooling calls.
Check the UCB for alarms indicating that compressor #1
is locked out. Press and release the ALARMS button if
the LED is not flashing an alarm.

2. Check for line voltage at the compressor contactor, M1,
and that the contactor is pulled in. Check for loose wiring
between the contactor and the compressor.

3. If M1 is pulled in and voltage is supplied at M1, lightly
touch the compressor housing. If it is hot, the compres­sor may be off on inherent protection. Cancel any calls
for cooling and wait for the internal overload to reset.
Test again when cool.

4. If M1 is not pulled in, check for 24 volts at the M1 coil. If
24 volts is present and M1 is not pulled in, replace the
contactor.

5. Failing the above, if voltage is supplied at M1 , M1 is
pulled in, and the compressor still does not operate,
replace the compressor.

6. If 24 volts is not present at M1, check for 24 volts at the
UCB terminal, C1. If 24 volts is present, check for loose
wiring between C1 and the compressor contactor.

7. If 24 volts is not present at the C1 terminal, check for 24
volts from the room thermostat at the UCB Y1 terminal.
If 24 volts are not present at the UCB Y1 terminal, the
UCB may have faulted. Check for 24 volts at the Y1
ECON terminal. If 24 volts is not present at Y1 “ECON”,
the UCB has faulted. The UCB should de-energize all
compressors on a loss of call for the first stage of cool­ing, i.e. a loss if 24 volts at the Y1 terminal.

8. If 24 volts are present at the UCB Y1 terminal, the com­pressor may be out due to an open high-pressure switch,
low-pressure switch, or freezestat. Check for 24 volts at
the HPS1, LPS1, and FS1 terminals of the UCB. If a
switch has opened, there should be a voltage potential
between the UCB terminals, e.g. if LPS1 has opened,
there will be a 24-volt potential between the LPS1 termi­nals.

9. If 24 volts is present at the UCB Y1 terminal and none of
the protection switches have opened, the UCB may have
locked out the compressor for repeat trips. The UCB
should be flashing a code. If not, press and release the
ALARMS button on the UCB. The UCB will flash the last
five alarms on the LED. If the compressor is locked out,
remove any call for cooling. This will reset any compres­sor lock outs.

NOTE: While the above step will reset any lock outs, com-

pressor #2 will be held off for the ASCD, and com­pressor #1 may be held off for a portion of the
ASCD. See the next step.

10. If 24 volts is present at the UCB Y1 terminal and none of
the switches are open and the compressor is not locked
out, the UCB may have the compressor in an ASCD.
Check the LED for an indication of an ASCD cycle. The
ASCD should time out within 5 minutes. Press and
release the TEST button to reset all ASCDs.

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127408-YIM-B-0606

11. If 24 volts is present at the UCB Y1 terminal and the
compressor is not out due to a protective switch trip,
repeat trip lock out, or ASCD, the economizer terminals
of the UCB may be improperly wired. Check for 24 volts
at the Y1 “OUT” terminal of the UCB. If 24 volts is
present, trace the wiring from Y1 “OUT” for incorrect wir­ing. If 24 volts is not present at the Y1 “OUT” terminal,
the UCB must be replaced.

12. For units without economizers: If 24 volts is present at
the Y1 “OUT” terminal, check for 24 volts at the Y1
“ECON” terminal. If 24 volts is not present, check for
loose wiring from the Y1 “OUT” terminal to the Mate-N­Lock plug, the jumper in the Mate-N-Lock plug, and in
the wiring from the Mate-N-Lock plug to the Y1 “ECON”
terminal.

For units with economizers:If 24 volts is present at the
Y1 “OUT” terminal, check for 24 volts at the Y1 “ECON”
terminal. If 24 volts is not present, check for loose wiring
from the Y1 “OUT” terminal to the Mate-N-Lock plug, a
poor connection between the UCB and economizer
Mate-N-Lock plugs, loose wiring from the Mate-N-Lock
plug to the economizer, back to the Mate-N-Lock plug,
and from the Mate-N-Lock plug to the Y1 “ECON”
terminal. The economizer control may have faulted and
is not returning the 24 volts to the Y1 “ECON” terminal
even though the economizer is not providing free
cooling. To test the economizer control, disconnect the
Mate-N-Locks and jumper between the WHITE and
YELLOW wires of the UCB’s Mate-N-Lock plug.

13. The UCB can be programmed to lock out compressor
operation during free cooling and in low ambient condi­tions. These options are not enabled by default. They
can be checked by local distributors.

For units with factory installed economizers, the UCB is
programmed to lock out compressor operation when the
LAS set point is reached.

For units without factory installed or with field installed
economizers, the UCB allows compressor operation all
the time. This programming can be checked or changed
by the local distributor.

14. If none of the above corrected the error, test the integrity
of the UCB. Disconnect the C1 terminal wire and jumper
it to the Y1 terminal. DO NOT jump the Y1 to C1 termi­nals. If the compressor engages, the UCB has faulted.

15. If none of the above correct the error, replace the UCB.

GAS HEAT TROUBLESHOOTING GUIDE

On calls for heating, the draft motor operates and the furnace
lights but the supply air blower motor does not energize after
a short delay (the room thermostat fan switch is in “AUTO”
position).

The furnace may shut down on a high temperature
condition during the procedure. If this occurs, the
UCB energize the supply air blower motor until the
high temperature limit has reset. Caution should be
used at all times as the supply air blower may ener­gize regardless of the room thermostat fan switch
position.

1. Place the thermostat fan switch in the “ON” position. If
the supply air blower motor energizes, go to Step 9.

2. If the supply air blower motor does not energize when
the fan switch is set to “ON,” check that line voltage is
being supplied to the contacts of the M3 contactor, and
that the contactor is pulled in. Check for loose wiring
between the contactor and the supply air blower motor.

3. If M3 is pulled in and voltage is supplied at M3, lightly
touch the supply air blower motor housing. If it is hot, the
motor may be off on inherent protection. Cancel any
thermostat calls and set the fan switch to “AUTO”, wait
for the internal overload to reset. Test again when cool.

4. If M3 is not pulled in, check for 24 volts at the M3 coil. If
24 volts is present at M3 but M3 is not pulled in, replace
the contactor.

5. Failing the above, if there is line voltage supplied at M3,
M3 is pulled in, and the supply air blower motor still does
not operate, replace the motor.

6. If 24 volts is not present at M3, check that 24 volts is
present at the supply air blower motor terminal on the
UCB. If 24 volts is present at the UCB terminal, check
for loose wiring between the UCB and M3.

a. If 24 volts is not present at the UCB supply air

blower motor terminal, check for 24 volts from the
room thermostat. If 24 volts is not present from the
room thermostat, check for the following:

i. Proper opera tion of the room thermostat (con-

tact between R and G with the fan switch in the
“ON” position and in the “AUTO” position during
operation calls)

ii. Proper wiring between the room thermostat and

the UCB, and

iii. Loose wiring from the room thermostat to the

UCB

7. If 24 volts is present at the room thermostat but not at the
UCB, check for proper wiring between the thermostat
and the UCB, i.e. that the thermostat G terminal is con­nected to the G terminal of the UCB, and for loose wir­ing.

8. If the thermostat and UCB are properly wired, replace
the UCB.

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127408-YIM-B-0606

9. If the blower motor runs with the fan switch in the “ON”
position but does not run shortly after the furnace has
ignited when the fan switch is in the “AUTO” position,
check the room thermostat for contact between R and G
during “W1” calls.

On calls for heating, the supply air blower operates but the
draft motor does not (the room thermostat fan switch is in the
“AUTO” position).

1. The draft motor has inherent protection. If the motor
shell is hot to the touch, wait for the internal overload to
reset.

2. If the motor shell is cold with the room thermostat calling
for heat, check for line voltage at the motor leads. If line
voltage is present, replace the draft motor.

3. If line voltage is not present, check for line voltage on the
ignition control at the “inducer” terminal draft motor relay
(DMR or DMC) contacts in the main control box and
check to see if the (DMR or DMC) is pulled in.

The draft motor runs but the furnace does not light and the
spark ignitor does not spark.

1. Check for 24 volts at the spark ignitor from the ignition
control board (ICB). Check the 24-volt wiring from the
ICB to the spark ignitor. Check for 24 volts at the ICB
spark ignitor terminal.

2. Check the ground wiring for the ICB and the gas valve is
intact and making good electrical connection. Check the
ceramic insulator on the spark ignitor for breaks or
cracks. Replace the spark ignitor if damaged.

3. With the draft motor running, check for 24 volts at the
pressure switch terminal on the ICB. If not present,
check for 24 volts on the terminal from the pressure

switch. If present, go to step 4. If 24 volts is not present,
the either pressure or rollout switch is not closed. Or the
draft motor is not sufficiently evacuating the heat
exchanger tubes or the pressure switch has failed.
Check the operation of the pressure switch. Check the
line voltage to the unit; if line voltage is low, call the local
power company. If the problem persists, the draft motor
may need replacement.

4. If the furnace is hot, it may be out on a high temperature
limit open; wait for limit reset.

5. If all are intact replace the ICB.

The draft motor runs and the spark ignitor sparks at the
burner, but the burner does not ignite and a gas odor is not
detected at the draft motor outlet.

1. Check to ensure gas is being supplied to the unit. Con­firm that the gas pressure to the unit is within the proper
limits as described in the “POST START CHECKLIST”.

2. Check the voltage at the gas valve and at the gas valve
terminals on the ICB. Check all wiring between the ICB
and the gas valve. Check to make sure the ground con­nections are intact.

3. If 24 volts is present, remove the pilot burner and the ori­fice. The removal procedure is described in “BURNER/
ORIFICE INSPECTION/SERVICING.” Inspect the orifice
for obstruction. If it is clear, replace the gas valve.

Main burners light but exhibit erratic flame characteristics.

4. Check the main burner orifices for ob struction and align­ment. The removal procedure is described in
“BURNER/ORIFICE INSPECTION/SERVICING”. Clean
or replace burner orifices and burners as needed.

58 Unitary Products Group

127408-YIM-B-0606

Unitary Products Group 59

Subject to change without notice. Printed in U.S.A. 127408-YIM-B-0606
Copyright © 2006 by Unitary Products Group. All rights reserved. Supersedes: 127408-YIM-A-0405

Unitary 5005 Norman
Products York OK
Group Drive 73069