Carrier 48MA-50ME016-040 User Manual

48MA/50ME016-040 Combination Multizone Heating/Cooling Units Gas, Electric, or Glycol Heat

Installation, Start-Up

and Service Instructions

CONTENTS

Page

SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 2

INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-34

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Unit Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Roof Curb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Roof Openings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Rigging Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Unit Positioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Removing Shipping Shields . . . . . . . . . . . . . . . . . . 5

Field-Fabricated Ductwork . . . . . . . . . . . . . . . . . . . . 5

Condensate Drains . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Gas Piping (48MA) . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Optional Glycol Connections (50ME) . . . . . . . . . 10

Field Power Supply Wiring . . . . . . . . . . . . . . . . . . 10

· UNIT COMMON FEED MINIMUM CIRCUIT AMPS

Field Control Wiring . . . . . . . . . . . . . . . . . . . . . . . . . 14

·ZONE THERMOSTATS

·ZONE MODULE CONNECTIONS

·ACCESSORY REMOTE CONTROL PANEL

Reheat Humidity Control . . . . . . . . . . . . . . . . . . . . 34

Optional Economizer . . . . . . . . . . . . . . . . . . . . . . . . 34

Optional Exhaust Damper . . . . . . . . . . . . . . . . . . . 34

START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34-39

Evaporator Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Compressor Rail Shipping Bolts . . . . . . . . . . . . . 34

Refrigerant Valves . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Zone Module Gas Valves (48MA) . . . . . . . . . . . . . 34

Gas Heat Lighting Procedure (48MA) . . . . . . . . . 35

· TO SHUT OFF GAS HEAT

Intermittant Pilots (48MA) . . . . . . . . . . . . . . . . . . . 35

·ADJUSTMENT

·PRESSURE ADJUSTMENT (NATURAL GAS)

Main Burner Adjustment (48MA) . . . . . . . . . . . . . 36

·ORIFICE ALIGNMENT

·PRIMARY AIR ADJUSTMENT

Outdoor-Air Thermostat Adjustment

(50ME With Electric Heat) . . . . . . . . . . . . . . . . . . 36

·UNITS WITH 2-ELEMENT HEATERS

·UNITS WITH 3-ELEMENT HEATERS

Optional Glycol Heating Coils . . . . . . . . . . . . . . . . 38

Zone Air¯ow Adjustment . . . . . . . . . . . . . . . . . . . . 38

Sequence of Operation . . . . . . . . . . . . . . . . . . . . . 38

·COOLING

·HEATING (48MA)

·HEATING (50ME WITH ELECTRIC HEAT)

·HEATING (50ME WITH GLYCOL HEATING COILS)

·OUTDOOR-AIR DAMPER

SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39-43

Cabinet Panels and Grilles . . . . . . . . . . . . . . . . . . 39

·SIDE PANELS

·TOP PANELS

·HEATER ACCESS PANELS

Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

·EVAPORATOR COILS (ZONE COOLING COILS) AND GLYCOL HEATING COILS

·CONDENSER AND OUTDOOR-AIR COOLING COILS

·CONDENSATE DRAINS

·INDOOR-AIR FILTERS

·OUTDOOR-AIR INLET SCREENS

·GAS HEATING SECTION

·COMBUSTION AIR FAN

Air¯ow Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

·INDOOR AIRFLOW SWITCH (AFS1)

·COMBUSTION AIRFLOW SWITCH (AFS2)

Service Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Time GuardT Control Circuit . . . . . . . . . . . . . . . . . 39

Capacity Control Pressure Switches (CCP)

(2-Compressor Units Only) . . . . . . . . . . . . . . . . 39

Compressor Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

· TO ADD OR REMOVE OIL

Compressor Capacity Control Unloader(s) . . . . 40

·CONTROL SET POINT

·PRESSURE DIFFERENTIAL

Crankcase Heater(s) . . . . . . . . . . . . . . . . . . . . . . . . . 40

Refrigerant Charge . . . . . . . . . . . . . . . . . . . . . . . . . . 40

·NO CHARGE

·LOW CHARGE

Head Pressure Control . . . . . . . . . . . . . . . . . . . . . . 40

·MOTORMASTERt HEAD PRESSURE CONTROL DEVICE

·FAN CYCLING PRESSURESTAT

Condenser Fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

·ADJUSTMENT

·FAN MOTOR REMOVAL

·LUBRICATION

Evaporator Fans and Motor . . . . . . . . . . . . . . . . . . 41

·MOTOR REMOVAL

·FAN SHAFT BEARING REMOVAL

·FAN SPEED ADJUSTMENT

·PULLEY REMOVAL

·PULLEY ALIGNMENT

·BELT TENSION ADJUSTMENT

·LUBRICATION

Forced-Draft Blower (48MA) . . . . . . . . . . . . . . . . . 42

·LUBRICATION

·AIR SHUTTER ADJUSTMENT

Zone Module Transformers . . . . . . . . . . . . . . . . . . 42

Optional Economizer . . . . . . . . . . . . . . . . . . . . . . . . 42

·THERMOSTAT SETTINGS

·DAMPER POSITION

·OPERATION

Optional Exhaust Damper . . . . . . . . . . . . . . . . . . . 42

Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . 42

START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . . . CL-1

Manufacturer reserves the right to discontinue, or change at any time, speci®cations or designs without notice and without incurring obligations.

Book	1	1		PC 111	Catalog No. 564-840	Printed in U.S.A.	Form 48MA/50ME-3SI	Pg 1	4-96	Replaces: 48MA/50ME-1SI
Tab	1c	1d

SAFETY CONSIDERATIONS

Installation and servicing of air-conditioning equipment can be hazardous due to system pressure and electrical components. Only trained and quali®ed service personnel should install, repair, or service air-conditioning equipment.

Untrained personnel can perform basic maintenance functions of cleaning coils and ®lters and replacing ®lters. All other operations should be performed by trained service personnel. When working on air-conditioning equipment, observe precautions in the literature, tags and labels attached to the unit, and other safety precautions that may apply.

Follow all safety codes, including ANSI (American National Standards Institute) Z223.1. Wear safety glasses and work gloves. Use quenching cloth for unbrazing operations. Have ®re extinguisher available for all brazing operations.

Before performing service or maintenance operations on unit, turn off main power switch to unit. Electrical shock could cause personal injury.

Do not try to light any appliance. Do not touch any electrical switch; do not use any phone in your building. Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions. If you cannot reach your gas supplier, call the ®re department.

Do not store or use gasoline or other ¯ammable vapors and liquids in the vicinity of the 48MA unit or any other gas-®red appliance.

Improper installation, adjustment, alteration, service, or maintenance can cause injury or property damage. Refer to this manual. For assistance or additional information, consult a quali®ed installer, service agency, or the gas supplier.

Disconnect gas piping from 48MA unit when leak testing at pressures greater than 0.5 psig. Pressures greater than 0.5 psig will cause gas valve damage resulting in a hazardous condition. If gas valve is subjected to pressure greater than 0.5 psig, it must be replaced. When pressure testing ®eld-supplied gas piping at pressures of 0.5 psig or less, the unit connected to such piping must be isolated by manually closing the gas valve.

INSTALLATION

General Ð Install unit on rooftop, outdoor site only. Install unit, electrical wiring, gas supply line (48MA) and condensate drain lines in accordance with all applicable codes.

Unit Clearances Ð See Fig. 1 and 2 for service and air¯ow clearances. For 48MA gas-®red units, provide not less than 36-in. clearance to combustibles from top and all sides. Keep burner end free from any obstruction.

Locate exit terminals of mechanical draft system (48MA ¯ue outlet) as follows:

·Not less than 12 in. from any opening through which combustion products could enter the building.

·Not less than 2 ft from any adjacent building.

·Not less than 7 ft above grade when unit is adjacent to public walkways.

Roof Curb Ð Assemble and install per instructions shipped with this accessory. Information required to ®eld fabricate a roof curb and other curb data are shown in Fig. 3-5.

Install ®eld-supplied insulation, cant strips, roo®ng and counter ¯ashing as required. Seal all curb joints with mastic or other suitable roof cement to keep out moisture. Be sure that run-off pan at compressor end of curb is completely flashed and sealed.

Seal strip (Fig. 3) is shipped with accessory roof curb. Install as described in the roof curb installation instructions. The seal strip compresses under unit weight so that an airtight seal and vibration isolation are provided between unit base and curb.

Roof Openings Ð Except for the compressor and condenser section, roof area under the unit need not be ®lled in as the curb-mounted unit encloses this space. Leaving this roof section open provides ample clearance for ductwork, piping, and power and control wiring.

If the roof area inside curb is to be ®lled in so that roof deck and bottom of base unit can be used as a return-air plenum, any spaces under the curb ¯anges caused by corrugated roo®ng or roof irregularities must be sealed to prevent water seepage. If spaces are not sealed, the negative pressure of return air may draw water under the unit and into the building structure.

If openings are cut in a ®nished roof, provide at least 6-in. space on each of the longer sides of the supply and return air openings. Due to interference from the roof curb structure, this additional clearance may not be possible on the short sides.

2

CONDENSER SECTION AIRFLOW

CONN Ð Connection

NOTES:

1.Space required for service and air¯ow all around and above unit is 36 inches.

2.For additional information see Fig. 4.

3.Center of gravity is within 6 in. radius of geometric center of unit.

4.Maximum allowable pitch of unit is 1¤2 in. per 10 ft in any direction.

Certi®ed dimension drawings available on request.

UNIT					DIMENSIONS (ft-in.)
48MA	A	B	C	D	E	F	G	H	J	K	L
016-030	7- 23¤4	3-05¤8	17-115¤16	2-215¤16	13-51¤2	0- 91¤16	2-10	7-33¤16	0-31¤8	0-31¤8	0-31¤8
034,040	7-11	3-915¤16*	21- 91¤16	4-25¤8	13-51¤2	0-111¤16	3- 45¤16	8-63¤4	0-31¤32	0-215¤16	0-71¤4

*Overall height; includes 13¤4-in. for fan guards.

Fig. 1 Ð Base Unit Physical Data and Dimensions; 48MA Units

3

CONDENSER SECTION AIRFLOW

CONN Ð Connection

NOTES:

1.Space required for service and air¯ow all around and above unit is 36 inches.

2.For additional information see Fig. 5.

3.Center of gravity is within 6 in. radius of geometric center of unit.

4.Maximum allowable pitch of unit is 1¤2 in. per 10 ft in any direction.

Certi®ed dimension drawings available on request.

UNIT				DIMENSIONS (ft-in.)
50ME	A	B	C	D	E		F	G	H	J
016-030	7- 23¤4	3-09¤16	17-115¤16	2-215¤16	13-51¤2		3-71¤16	7-33¤16	0-31¤8	0-31¤8
034,040	7-11	3-915¤16*	21-91¤16	4-25¤8	13-51¤2		4-4	8-63¤4	0-215¤16	0-71¤4

*Overall height; includes 13¤4-in. for fan guards.

Fig. 2 Ð Base Unit Physical Data and Dimensions; 50ME Units

4

AIRFLOW

*Factory supplied (with accessory roof curb). ²Field supplied (when using accessory roof curb).

NOTE: Dimensions are in inches.

Fig. 3 Ð Roof Curb Detail

Rigging Unit Ð Inspect unit for shipping damage, and ®le any damage claim immediately with transportation company.

Lift unit with cables and spreader bars, using lifting brackets provided (Fig. 1 and 2). Lift one unit at a time, keep unit upright, and do not drop. Unit weights are given in Table 1. Unit center of gravity is within 6 in. of unit's geometric center. Eyebolts may be removed after unit is in ®nal position.

IMPORTANT: Do not drill or punch holes in unit frame or panels; damage to internal components or wiring may result.

Unit Positioning Ð When lowering unit onto roof curb, do not exceed the out-of-symmetry tolerances given in Fig. 4 and 5. Be sure unit is level or is pitched within speci- ®ed tolerances. Units have drains on both sides and may be pitched to either side.

Removing Shipping Shields (Fig. 6)

1.Remove shield over ¯ue outlet grille (48MA only).

2.Remove shields (sheet metal covers) located in the outdoorair inlet screen tracks behind the louvers. If the screens are removed for this procedure, be sure to replace them before replacing the louvered assembly.

Field-Fabricated Ductwork Ð Supplyand returnair openings are shown in Fig. 4 and 5. To simplify supplyair connection, a zone duct plenum may be ®eld fabricated as shown in Fig. 7. It is recommended that this plenum be installed prior to unit positioning.

It is recommended that the unit be supported on blocks temporarily while the duct plenum is installed, rather than installing the plenum while the unit is suspended. The duct plenum may be installed once the unit is located in its ®nal position, but it is much easier to install the plenum prior to unit ®nal placement.

Zone supply-air duct openings on the base unit have tab slot connections similar to those shown in Fig. 7 except that the end partitions are hemmed. Hem is positioned so that the 1-in. ¯ange at entering end of ®eld-fabricated plenum will force-®t between hem and adjacent unit frame.

Standard ¯exible duct connections between duct plenum and duct system may be used. Follow applicable codes.

Insulate any supply-air ducts passing through unconditioned spaces and cover with a vapor barrier. Separate ducts with insulation if they run parallel for more than 5 ft. This will prevent heat transfer between zones.

Install a manual balancing damper in each zone duct to provide the required zone air¯ow.

The return-air duct connection consists of 4 sheet metal ¯anges as shown in Fig. 1, 2, 4, and 5.

5

Table 1 Ð Physical Data

	UNIT 48MA/50ME		016	024		028		030	034		040
	Zone Modules (Quantity)		8	8		10		10	12		12
	Nominal Cooling Capacity (tons)		15	20		25		28	30		37
	OPERATING WEIGHT (lb)
	Base Unit 48MA		3395	3815		4075		4080	5340		5710
	Base Unit 50ME (with electric heat)		2995	3415		3675		3680	4900		5270
	Roof Curb		506	506		506		506	630		630
	REFRIGERANT CHARGE Ð R-22 (lb)		28	32		43		43	57		66.1
	COMPRESSOR				Reciprocating Hermetic, 1725 Rpm
	No. 1 Type		06DE537	06DE824		06DE537		06DE537	06DE537		06EE250
	Cylinders...Unloaders		6...2	6...2		6...2		6...2	6...2		4...1
	No. 2 Type		Ð	06DA824		06DA824		06DA537	06DA537		06EA250
	Cylinders (have no unloaders)		Ð	6		6		6	6		4
	System Oil Charge (pints)		11	18		18		18	18		31
	Unloader Settings (psig)	Loads				Compressor No. 1 Only
	Unloader No. 2				71.0 ± 1.5						Ð
		Unloads			57.5 ± 2.5						Ð
	Unloader No. 1	Loads			75.0 ± 1.5						75.5 ± 1.5
		Unloads			62.5 ± 2.5						58.0 ± 2.5
	Capacity Steps (%)		100,67,33	100,83,67		100,80,60		100,80,60	100,83,67		100,75,
				50,33,17		40,20		40,20	50,33,17		50,25
	CONDENSER FANS					Propeller, Direct Drive
	Motor Hp...Rpm...Frame (NEMA)
		No. 1				1...1075...56 (Single phase)
		No. 2				1...1140...56 (3 phase)
	Nominal Cfm	No. 3	Ð	Ð		Ð		Ð	1...1140...56 (3 phase)
			16,500	15,000		15,000		15,000	24,000		23,000
	EVAPORATOR FANS*					Centrifugal, Belt Drive
	Number...Size (in.)		2...15 × 15	2...15 × 15		2...15 × 15		2...15 × 15	3...15 × 9		3...15 × 9
	Cfm (Nominal)	Std	6000	8000		10,000		10,000	12,000		12,000
	Motor Hp...Rpm		5...1725	71¤2...1725		10...1725		10...1725	15...1725		15...1725
		Alt	Ð	Ð		Ð		Ð	20...1725		20...1725
	Fan Pulley
	Outside Diameter (in.)		10.6	10.6		8.0		8.0	8.0		8.0
	Bore (in.)	Std	13¤16	13¤16		13¤16		13¤16	111¤16		111¤16
	Fan Belt Number...Size		1...3V630	1...3V630		2...3V560		2...3V560	2...3V630		2...3V630
		Alt	Ð	Ð		Ð		Ð	3...3V670		3...3V670
	Motor Pulley	Std				Factory Installed
	Outside Diameter (in.)		5.3	6.0		5.0		5.0	5.0		5.0
		Alt	Ð	Ð		Ð		Ð	6.0		6.0
	Bore (in.)
		Std	11¤8	13¤8		13¤8		13¤8	15¤8		15¤8
	Resulting Fan Rpm		880	995		1095		1095	1095		1095
		Alt	Ð	Ð		Ð		Ð	1320		1320
	Shaft Center Line Distance (in.)		18 ± 2.5	18 ± 2.5		18 ± 2.5		18 ± 2.5	21 ± 2.5		21 ± 2.5
	Maximum Fan Rpm		1300	1300		1300		1300	1550		1550
	CONDENSER COOLING COIL			Thermostatic Expansion Valve, Hot Gas Bypass
	Face Area (sq ft)		6.8	6.8		6.8		6.8	10.2		10.2
	Corrugated Fins/in. ...Rows		13...2	13...2		13...2		13...2	13...2		13...3
	EVAPORATOR COILS (zone)			Solenoid Valve and Capillary Tube for each
	Number...Face Area (sq ft/ea)		8...2.12	8...2.12		10...2.12		10...2.12	12...2.01		12...2.01
	Corrugated Fins/in. ...Rows		13...3	13...3		13...3		13...3	12...3		15...3
	HEATING SECTION (48MA)			One Heat Assembly in Each Zone Module
	Rise Range	Total				25 F to 55 F at 0.75 in. wg ESP
	Input (1000 Btuh)		432	432		540		540	648		648
		Each Module	54	54		54		54	54		54
	Bonnet Cap.² (1000 Btuh)	Total	324	324		405		405	486		486
		Each Module	40.5	40.5		40.5		40.5	40.5		40.5
	Burner Spud Qty...Size		2...38	2...38		2...38		2...38	2...38		2...38
	OPTIONAL HEATING SECTION (50ME Electric)
	Electric Heaters			Nichrome, Open-Wire Resistance Element in Each Zone Module
	Qty...Elements (each)**		8...2 or 3	8...2 or 3		10...2 or 3		10...2 or 3	12...2 or 3		12...2 or 3
	OPTIONAL HEATING SECTION				One Heating Coil in Each Zone Module
	(50ME Glycol Coil)
	Maximum Allowable Inlet Temperature (F)						200
	Maximum Allowable Flow, Each Coil (Gpm)						6
	Solution Mixture					20% Glycol
	Maximum Allowable Working Pressure (Psig)						30
	Total Internal Volume (Gal)		2.61	2.61		3.15		3.15	3.76		3.76
	PRESSURE SWITCHES	Cutout					29 ± 5
	Low-Pressure (Psig)
		Cut-in					39 ± 5
	High-Pressure (Psig)	Cutout			400 ± 5
		Cut-in			300 ± 5
	Indoor Air¯ow Switch (AFS1)
	Factory Setting (cfm)				6000					9000
	Adjustment Range (cfm)			4000-6000					6000-9000
	INDOOR AIR FILTERS
	Standard Qty...Size (in.)				12...20 × 25 × 2
	High Efficiency (optional)					12...20 × 2 5 × 2 (36.5% Efficient)
	Qty...Size (in.)
	OUTDOOR AIR FILTERS
	Qty...Size (in.)			2...20 × 25 × 1					2...32 × 35 × 1

	LEGEND
ESP Ð	External Static Pressure
NEMA Ð	National Electrical Manufacturers Association

*Standard unit shipped with standard motor, pulley, and belt(s); alternate unit shipped with alternate motor, pulley, and belt(s).

²The heating efficiency rating is a product thermal efficiency rating determined under continuous operating conditions independent of any installed system. **See Field Power Supply Wiring section on page 10 and Table 4 for details.

6

EVAPORATOR (ZONE MODULE) AIRFLOW

CONN Ð Connection

*Not used on 48MA016,024 (8 zone module units).

NOTES:

1. For additional information, see Table 1 and Fig. 1.

2. Maximum allowable unit pitch is 1¤2 in. per 10 ft in any direction. 3. Remove shipping brace before assembling curb section (location

shown).

UNIT				DIMENSIONS (ft-in.)
48MA	A	B	C	D	E	F	G	H	J
016-030	18-21¤8	7- 3	11-9	5-61¤4	7-27¤8	1-109¤16	2-29¤16	6-03¤8	0- 71¤2
034,040	21-97¤8	7-113¤4	14-13¤4	6-77¤16	8-43¤16	2- 91¤8	3-1	6-81¤2	0-105¤16

Fig. 4 Ð Roof Curb Physical Data and Dimensions; 48MA Units

7

END DETAIL

(034,044 12-ZONE MODULES)

EVAPORATOR (ZONE MODULE) AIRFLOW

CONN Ð Connection

*Not used on 50ME016,024 (8 zone module units).

NOTES:

1.For additional information, see Table 1 and Fig. 2.

2.Maximum allowable unit pitch is 1¤2 in. per 10 ft in any direction.

3.Remove shipping brace before assembling curb section (location shown).

UNIT				DIMENSIONS (ft-in.)
50ME	A	B	C	D	E	F	G	H	J
016-030	18-21¤8	7- 3	11-9	5-61¤4	7-27¤8	1-109¤16	2-29¤16	6-03¤8	0- 71¤2
034,040	21-97¤8	7-113¤4	14-13¤4	6-77¤16	8-43¤16	2- 91¤8	3-1	6-81¤2	0-105¤16

Fig. 5 Ð Roof Curb Physical Data and Dimensions; 50ME Units

8

Condensate Drains Ð Pipe nipples covered with foam rubber insulation are shipped in unit return air ®lter section (6 nipples in units 48MA, 4 nipples in units 50ME). Install a nipple in each drain connection on both sides of unit. See Fig. 1 and 2 for drain locations. Be sure foam rubber seals space between nipple and base rail opening to prevent rain leaks.

Connect a drain line to drain connection under outdoor air inlet grilles on both sides of unit. These drains need not be trapped.

Install a trapped drain line on remaining connections on lowest side of unit depending on unit pitch. If unit is level, a trapped drain may be installed at each connection if desired. Cap or plug unused connections on high side of unit to prevent air¯ow between unit interior and outdoors.

	OUTDOOR AIR INLET
	(ONE ON EACH SIDE OF UNIT)	FLUE OUTLET
	SHIPPING SHIELD
		COVER
	(BEHIND LOUVERS)
		(48MA ONLY)

Fig. 6 Ð Shipping Shield Locations

(016-030 Units Shown)

Do not interconnect drains. Make each trap a minimum of 4 in. deep. Insulate trap against freeze-up or use ¯exible material.

Gas Piping (48MA) Ð Unit is equipped for use with type of gas shown on nameplate. Refer to latest edition of ANSI Z223.1. Unit main gas connection and alternate gas connection locations are shown in Fig. 1, 4, and 8. Do not use gas supply pipe smaller than unit gas connection. Maximum allowable natural gas supply pressure is 10.0 in. wg; minimum allowable natural gas supply pressure for full rate input is 5.0 in. wg.

Pitch pipe 1¤4 in. per 15 ft. Pitch all horizontal pipe runs upward to risers and from risers upward to meter. Install a dirt and moisture pocket (drip leg) at each section of vertical pipe run. Use only ground joint unions to ensure leakfree joints. Use only pipe joint compounds that are resistant to the action of lique®ed petroleum gases.

NOTE: Dimension to suit job requirements. Twelve inches will bring duct plenum to bottom of roof curb.

DIMENSIONS (in.)

	UNIT	016,024	028,030	034,040
	48MA,50ME
	A*	75¤8	75¤8	75¤16
	B*	75¤8	73¤4	53¤4

*Typical; both ends.

Fig. 7 Ð Field-Fabricated Zone Duct Plenum Detail

9

*Shutoff valve not used except where required by code.

Properly cap any gas connection not being used.

Fig. 8 Ð Suggested Gas Piping (48MA)

Unit has factory-installed gas shutoff valves. Install gas shutoff valve external to unit if required by code (Fig. 8). After piping is complete, pressurize gas line and check for leaks with soap and water solution.

Do not use an open ¯ame when checking for gas leaks.

Optional Glycol Connections (50ME) Ð Each zone module has its own glycol heating coil and 115-v solenoid valve. Heating coils are connected in parallel to common supply and return manifolds. Supply manifolds are equipped with bleed cocks. Supply and return connections are shown in Fig. 2 and 5. Unit does not have internal pressure relief for part-load operation. Maximum allowable system working pressure is 30 psig. Unit ratings are based on 20% glycol solutions. Install solution supply apparatus in accordance with application requirements, and mix glycol solution percentage in accordance with glycol manufacturer's recommendations. Freeze-up protection is not factory installed.

Field Power Supply Wiring Ð When installed, unit must be electrically grounded in accordance with local codes or, in the absence of local codes, with the National Electrical Code (NEC).

Unit has a circuit breaker for each compressor, each fan motor, and for each 50ME electric resistance heater assembly (if unit is so equipped). If required by local code, provide an additional disconnect switch in accordance with code being followed.

All units have a main power supply terminal board in the power and condensing control box. The electric resistance heater power supply terminal board(s) (if unit is so equipped) on 50ME units is located in the heater control box at front of unit. See Fig. 2, 5, and 9.

All terminal boards are suitable for use with copper or aluminum wire.

Connect electrical conduit (a threaded pipe nipple) shipped with unit to threaded ®tting in roof curb and bottom of main power and condensing section control box. Route main power wires through conduit to terminal board in box as shown on unit label wiring diagram and in Fig. 9.

When installing 48MA,50ME040 units with optional 20-hp motor, the electrical conduit interconnecting the curb and control box power wire openings will not accommodate aluminum wire of the size that may be required. If aluminum wire cannot be accommodated, an external transition box and short lengths of no. 300 kcmil, 75 C copper wire from the transition box to the unit main power connection are recommended.

Voltage to compressor terminals during compressor operation must be within voltage range indicated on unit nameplate. Phases must be balanced within 2%.

	LEGEND
EQUIP	Ð Equipment
GND	Ð Ground
TB	Ð Terminal Board

*208/230 v units only.

Fig. 9 Ð Field Power Supply Details

10

Use the following formula to determine the percent voltage imbalance.

% Voltage Imbalance:

	= 100 ×	max voltage deviation from average voltage
		average voltage

EXAMPLE: Supply voltage is 460-3-60.

AB = 452 v

BC = 464 v

AC = 455 v

452 + 464 + 455

Average Voltage =

3

1371

=

3

= 457

Determine maximum deviation from average voltage.

(AB) 457 − 45 2 = 5 v (BC) 464 − 45 7 = 7 v (AC) 457 − 45 5 = 2 v

Maximum deviation is 7 v.

Determine percent voltage imbalance:

7

% Voltage Imbalance = 100 x

457

= 1.53%

This amount of phase imbalance is satisfactory as it is below the maximum allowable 2%.

IMPORTANT: If the supply voltage phase imbalance is more than 2%, contact your local electric utility company immediately.

Unit failure as a result of operation on improper line voltage or excessive phase imbalance constitutes abuse and may cause damage to electrical components. See Tables 2-5 for unit, electric heater, and 50ME electrical application electrical data.

Each 50ME electric heat unit is ®tted with a heating lockout circuit (if equipped with optional heat). If any zone module is operating on mechanical cooling (compressor is operating), the heating element in each zone module is locked out and cannot be energized.

On 50ME units, cooling power supply wires and electric heater power supply wires (if applicable) must be sized according to the cooling MCA (Minimum Circuit Amps) values and heating MCA values shown on unit nameplate and in Tables 3-5. These wires may be powered by a common power supply (i.e., a pull-box junction), if desired. The common power supply wires from the main power source to the junction must be sized according to the common MCA values shown in Table 5.

UNIT COMMON FEED MINIMUM CIRCUIT AMPS Ð The unit common feed MCA is calculated on the basis of either: the sum of the cooling MCA plus 1¤2 heating MCA on units with 2 heating elements per zone module (or 2¤3 heating MCA on units with 3 heating elements per zone module) or the sum of the evaporator fan motor full load amps, per NEC, plus the full heating MCA, whichever is larger. Field wiring must conform to NEC limitations for Type T wire.

Table 2 Ð Unit 48MA Electrical Data

UNIT	Voltage	VOLTAGE		COMP		COMP			OFM		COMBUSTION		IFM		POWER
		RANGE		NO. 1		NO. 2			FLA		FAN MOTOR				SUPPLY
48MA	(3 Ph, 60 Hz)
		Min	Max	RLA	LRA	RLA	LRA	No. 1	No. 2	No. 3	FLA	Hp		FLA	MCA	MOCP
	208/230	187	254	63.6	266				6.6					16.2	109.6	125
016	460	414	508	28.6	120	Ð	Ð	6.2	3.0	Ð	1.8	5		6.6	49.8	60
	575	518	632	22.8	96				2.4					5.6	39.8	45
	208/230	187	254	44.4	170	44.4	170		6.6					24.2	137.5	150
024	460	414	508	19.9	77	19.9	77	6.2	3.0	Ð	1.8	7.5		11.0	62.2	70
	575	518	632	15.7	62	15.7	62		2.4					9.0	49.4	60
	208/230	187	254	63.6	266	44.4	170		6.6					30.8	168.1	200
028	460	414	508	28.6	120	19.9	77	6.2	3.0	Ð	1.8	10		13.0	76.1	90
	575	518	632	22.8	96	15.7	62		2.4					10.5	60.4	70
	208/230	187	254	63.6	266	63.6	266		6.6					30.8	187.3	200
030	460	414	508	28.6	120	28.6	120	6.2	3.0	Ð	1.8	10		13.0	84.5	100
	575	518	632	22.8	96	22.8	96		2.4					10.5	67.5	90
	208/230	187	254	63.6	266	63.6	266		6.6	6.6		15		46.2	210.8	225
												20		61.0	224.6	250
034	460	414	508	28.6	120	28.6	120	6.2	3.0	3.0	1.8	15		21.0	94.5	100
												20		26.6	100.5	125
	575	518	632	22.8	96	22.8	96		2.4	2.4		15		16.0	75.6	90
												20		21.3	80.6	100
	208/230	187	254	80.0	345	80.0	345		6.6	6.6		15		46.2	247.7	300
												20		61.0	261.5	300
040	460	414	508	38.5	150	38.5	150	6.2	3.0	3.0	1.8	15		21.0	116.7	150
												20		27.0	122.7	150
	575	518	632	31.4	120	31.4	120		2.4	2.4		15		16.0	95	125
												20		21.3	100	125

	LEGEND
COMP Ð Compressor
FLA	Ð Full Load Amps
IFM	Ð Indoor (Evaporator) Fan Motor
LRA	Ð Locked Rotor Amps
MCA	Ð Minimum Circuit Amps

MOCP Ð Maximum Overcurrent Protection

OFM	Ð	Outdoor (Condenser) Fan Motor
RLA	Ð	Rated Load Amps

NOTES:

1.Combustion air fan is a 115-1-60 motor on all units.

2.Condenser fan motor no. 1 is a 208/230-1-60 speed control motor on all units.

11

Table 3 Ð Unit 50ME Electrical Data

UNIT	VOLTAGE	VOLTAGE		COMP		COMP			OFM			IFM		POWER
		RANGE		NO. 1		NO. 2			FLA					SUPPLY
50ME	(3 Ph, 60 Hz)
		Min	Max	RLA	LRA	RLA	LRA	No. 1	No. 2	No. 3	Hp		FLA	MCA	MOCP
	208/230	187	254	63.6	266				6.6				16.2	109.6	125
016	460	414	508	28.6	120	Ð	Ð	6.2	3.0	Ð	5		6.6	49.5	60
	575	518	632	22.8	96				2.4				5.6	39.6	45
	208/230	187	254	44.4	170	44.4	170		6.6				24.2	138.0	150
024	460	414	508	19.9	77	19.9	77	6.2	3.0	Ð	7.5		11.0	61.9	70
	575	518	632	15.7	62	15.7	62		2.4				9.0	49.2	60
	208/230	187	254	63.6	266	44.4	170		6.6				30.8	168.9	200
028	460	414	508	28.6	120	19.9	77	6.2	3.0	Ð	10		13.0	75.8	90
	575	518	632	22.8	96	15.7	62		2.4				10.5	60.2	70
	208/230	187	254	63.6	266	63.6	266		6.6				30.8	188.0	200
030	460	414	508	28.6	120	28.6	120	6.2	3.0	Ð	10		13.0	84.5	100
	575	518	632	22.8	96	22.8	96		2.4				10.5	67.3	90
	208/230	187	254	63.6	266	63.6	266		6.6	6.6	15		46.0	210.8	225
											20		61.0	224.6	250
034	460	414	508	28.6	120	28.6	120	6.2	3.0	3.0	15		19.8	94.5	100
											20		26.6	100.5	125
	575	518	632	22.8	96	22.8	96		2.4	2.4	15		16.0	75.6	90
											20		21.3	80.6	100
	208/230	187	254	80.0	345	80.0	345		6.6	6.6	15		46.2	247.7	300
											20		61.0	261.5	300
040	460	414	508	39.3	150	39.3	150	6.2	3.0	3.0	15		19.8	118.5	150
											20		26.6	124.5	150
	575	518	632	31.4	120	31.4	120		2.4	2.4	15		16.0	95	125
											20		21.3	100	125

	LEGEND
COMP Ð Compressor
FLA	Ð Full Load Amps
IFM	Ð Indoor (Evaporator) Fan Motor
LRA	Ð Locked Rotor Amps
MCA	Ð Minimum Circuit Amps
MOCP	Ð Maximum Overcurrent Protection
OFM	Ð Outdoor (Condenser) Fan Motor
RLA	Ð Rated Load Amps

NOTE: Condenser fan motor no. 1 is a 208/230-1-60 speed control motor on all units.

Table 4 Ð Electric Resistance Heater Data

	UNIT	NOMINAL	ELECTRIC		HEATING ELEMENTS	FLA PER	MCA	MOCP
		VOLTAGE	HEAT kW
	50ME				PER ZONE MODULE	HEATING ELEMENT	(Each Circuit)	(Each Circuit)
		(3 Ph, 60 Hz)	(Unit Total)
			43/	53	2	13.0/14.4	150/166	175/175
		208/230	57/	70	2	17.3/19.2	200/221	225/225
			87/106		3	17.3/19.2	150/166	175/175
	016,024		53		2	7.2	83	90
		460	70		2	9.6	111	125
			106		3	9.6	166	175
		575	106		3	7.7	133	150
			54/	66	2	13.0/14.4	188/207	200/225
		208/230	72/	88	2	17.3/19.2	250/276	275/300
			108/132		3	17.3/19.2	188/207	200/225
	028,030		66		2	7.2	103	110
		460	88		2	9.6	138	150
			132		3	9.6	207	225
		575	132		3	7.7	166	175
			65/	79	2	13.0/14.4	225/249	250/250
		208/230	87/106		2	17.3/19.2	150/165	175/175
			129/158		3	17.3/19.2	225/249	250/250
	034,040		79		2	7.2	124	125
		460	106		2	9.6	166	175
			158		3	9.6	249	250
		575	158		3	7.7	199	200

		LEGEND
FLA	Ð	Full Load Amps
MCA	Ð	Minimum Circuit Amps
MOCP Ð		Maximum Overcurrent Protection

NOTES:

1.Heaters are rated at 230 v, 460 v, and 575 v.

2.Terminal boards provided for heater power wire connections are suitable for use with copper or aluminum wire.

12

Table 5 Ð Unit 50ME Electrical Application Data

	UNIT							MCA
	50ME		NOMINAL	kW				Heating		Unit
				(Unit				Circuit
			VOLTAGE			Cooling				Common
				Total)
Size		IFM					1		2	Feed
		Hp
				43/	53		150.0/165.6		Ð	184.8/192.6
			208/230	57/	70	109.8/109.8	200.0/220.9		Ð	216.7/237.6
				87/106			150.0/165.8		150.0/165.8	316.7/348.3
016		5		53			82.9			90.9
			460	70		49.5	110.5		Ð	117.1
				106			165.8			172.4
			575	106		39.6	132.5		Ð	138.1
				43/	53		150.0/160.6		Ð	213.0/220.8
			208/230	57/	70	138.0/138.0	200.0/220.9		Ð	238.0/248.5
				87/106			150.0/165.8		150.0/165.8	342.2/359.0
024		7.5		53			82.9			103.4
			460	70		61.9	110.5		Ð	121.5
				106			165.8			176.8
			575	106		49.2	132.5		Ð	141.5
				54/	66		188.0/207.1		Ð	262.9/272.5
			208/230	72/	88	168.9	250.0/276.1		Ð	293.9/307.0
				108/132			188.0/207.1		188.0/207.1	419.6/445.0
028		10		66			102.8			127.2
			460	88		75.8	138.0		Ð	151.0
				132			207.1			220.1
			575	132		60.2	165.6		Ð	176.1
				54/	66		188.0/207.1		Ð	282.0/291.6
			208/230	72/	88	188.0	250.0/276.1		Ð	313.0/326.0
				108/132			188.0/207.1		188.0/207.1	438.7/464.0
030		10		66			102.8			135.9
			460	88		84.5	138.0		Ð	153.5
				132			207.1			222.6
			575	132		67.3	165.6		Ð	177.7
				65/	79		225.0/248.5		Ð	323.3/335.1
			208/230	87/106		210.8	150.0/165.6		150.0/165.1	360.8/376.4
				129/158			225.0/248.5		225.0/248.5	510.9/543.2
		15		79			124.3			156.7
			460	106		94.5	165.1		Ð	185.4
				158			248.5			268.3
034			575	158		75.6	198.8		Ð	214.8
				65/	79		225.0/248.5		Ð	337.1/348.9
			208/230	87/106		224.6	150.0/165.1		150.0/165.1	374.6/391.2
				129/158			225.0/248.5		225.0/248.5	524.6/558.0
		20		79			124.3			162.7
			460	106		100.5	165.6		Ð	192.2
				158			248.5			275.1
			575	158		80.6	198.8		Ð	220.1
				65/	79		225.0/248.5		Ð	360.2/372.0
			208/230	87/106		247.7	150.0/165.1		150.0/165.1	397.7/412.8
				129/158			225.0/248.5		225.0/248.5	547.7/579.0
		15		79			124.3			178.9
			460	106		116.7	165.6		Ð	199.5
				158			248.5			282.4
040			575	158		95.0	198.8		Ð	227.5
				65/	79		225.0/248.5		Ð	374.0/385.8
			208/230	87/106		261.5	150.0/165.1		150.0/165.1	411.5/426.6
				129/158			225.0/248.5		225.0/248.5	561.5/592.8
		20		79			124.3			148.9
			460	106		122.7	165.6		Ð	205.5
				158			248.5			288.4
			575	158		100.0	198.8		Ð	232.5
		LEGEND
IFM Ð	Indoor (Evaporator) Fan Motor
MCA Ð Minimum Circuit Amps

13

Field Control Wiring

ZONE THERMOSTATS Ð Install a Carrier approved accessory zone thermostat assembly in each zone according to installation instructions included in the accessory. Locate each thermostat assembly in the space where it will sense average zone temperature.

Route thermostat cable or equivalent single leads of no. 18 AWG (American Wire Gage) colored wire from thermostat subbase terminals through opening on base unit (Fig. 1, 2, 4, and 5) to low-voltage thermostat connections on zone control board (Fig. 10). Use no. 16 AWG wire for lengths exceeding 50 ft.

ZONE MODULE CONNECTIONS Ð Any module may be controlled independently or jointly with another module or modules. Modules are combined into nests that form individual Class II circuits (40 va) as follows:

Modules no. 1 and 2, 3 and 4, 5 and 6, 7 and 8, 9 and 10 (028-040 units), 11 and 12 (034,040 units).

The control signal	can	be transferred from one nest
to another nest by	using	factory-supplied jumpers on

quick-connect type multiplexing terminals. This prevents overloading the nest control transformers. Factory-supplied jumpers with quick-connect terminals are shipped in the zone control and thermostat panel compartment.

Under no circumstances shall the transformer power from one Class II circuit be interconnected with any other circuit.

Thermostat heat anticipator settings are indicated for each permitted zone module connection arrangement illustrated in Fig. 11-28.

To Join Modules of the Same Nest Into the Same Zone (i.e., modules no. 1 and 2) Ð Install ®eld-supplied jumpers on thermostat connections (screw terminals) Y to Y and W2 to W2 as shown in Fig. 11. Connect thermostat wires to terminal connections of ®rst module in zone (for consistency). Two-stage cooling may be obtained in this example as shown in Fig. 12 (using a 2-stage thermostat).

To Join Modules Not of the Same Nest Into the Same Zone (i.e., modules no. 2 and 3) Ð Install the factory-supplied jumpers on quick-connect terminals 6 to 1, 7 to 2, and 8 to 3 as shown in Fig. 13. Note that module no. 1 is independently controlled by its own thermostat (in Fig. 13).

	LEGEND
AFS	Ð Air¯ow Switch
CR	Ð Control Relay
ECR	Ð Economizer Relay
ECT	Ð Economizer Outdoor-Air Thermostat
GV	Ð Gas Valve (not used on 50ME units)
HC	Ð Heater Contactor
HR	Ð Heater Relay
IFC	Ð Indoor (Evaporator) Fan Contactor
LLS	Ð Liquid Line Solenoid
MC	Ð Master Cooling
MCR	Ð Master Cooling Relay
MH	Ð Master Heating
MHR	Ð Master Heating Relay
MU	Ð Master Unit
MUR	Ð Master Unit Relay
NC	Ð Normally Closed
NO	Ð Normally Open
NS	Ð Night Setback
SW	Ð Switch

TRAN Ð Transformer

Quick-Connect Type Terminals (for multiplexing)

Screw-Type Terminals

NOTE: Twelve-zone unit shown. Eight-zone units have modules 1-8 only. Ten-zone units have modules 1-10 only.

Fig. 10 Ð Zone Control Board Component Location

14

Fig. 10 Ð Zone Control Board Component Location (cont)

15