Carrier 19CB User Manual

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Page 1

Carrier

Airconditioning

Company

Hermetic Centrifugal Liquid Chillers

CONTENTS

INTRODUCTION

General Job Data Required Equipment Required

INITIAL PREPARATION

Machine Tightness Check for Large Leaks Check for Small Leaks Check Leakage Rate Machine Dehydration Pumpout Procedures Oil Charge Oil Heater

Refrigerant Charge Inspect Piping Field Wiring Check Starter Check Operation of Safety Controls Purge Air Supply (Pneumatic Controls Only)

START-UP

Before Starting Machine

Compressor Rotation

Compressor Operation

Checking Safety Control Settings

Setting Operating Controls — Electronic

Motor Current Calibration Chilled Water Calibration

Setting Operating Controls — Pneumatic

FINAL MACHINE ADJUSTMENT

Trimming Refrigerant Charge

INSTRUCTING THE CUSTOMER OPERATOR

Page

3 3 3 3 4 4 4 5 5 5

7 7

7 7 7

9 9

10 12

INTRODUCTION

General — All persons involved in start-up and

operation of the 19CB machine should be famihar with these instructions and all necessary job data before initial start-up. Instructions are arranged in proper sequence for machine start-up.

Job Data Required

1. List of applicable design temperatures and pressures

2. Machine assembly, wiring and piping prints 3 19CB Installation Instructions

4. 19CB Operating and Maintenance Instructions

Equipment Required

1. Mechanic’s tools

2 Volt-ohmmeter and clamp-on ammeter

3. Manometer, absolute pressure type

4. Leak detector, halide or electronic

5. Refrigerant drum charging valve (Fig. 5)

6. 5/8-in. SAE X 3/4-in. MPT adapter

7. Five to ten ft of copper tubing or plastic hose to fit 5/8-in. SAE connections

8. Portable vacuum pump

INITIAL PREPARATION

CAUTION: Do noi start compr&ssox or oil pump, even for a rotation check, unless conv pxessor is charged with <ni and machine charged with refrigerant.

Do not apply voltage of my kina wihle

machine is under dehydration vacuum.

Form 19CB-2SS

Page 2

— Cooler

— Cooler Ret:igerant Level Sight Glass

— Low Refrigerant Temoerature Sulb

— Thermometer Well

— Machir.e Control Ceitter

(See Rig.:«.) ,

~ KnockouwforRieici Wiritts :

— Condenser

— Cooler S'.jotion Pipe

— Condettser Discharge Ripe

—, Condenser Float Valve;

ÎO

— iiconomiser Pipe

12 — Cooler-Econorttize: Epuati^iitg Damper

Access Cover

■ 53 - Refrigerant Connection, 1 1/2 NRT

14 — Cooler Charging Valve, 3/4 NPT

15 — AS:Vi£ Nomepiats

16:Machine informative Plate 17 — Safety Code Sticker

IS — Cooler Watsrbcx vent, 3/4 MPT

13 — Condenser W'arerbox Drain, 3/4 MPT

20 — Condenser Waterdox Vent, 3/4 MPT

21 — iiconomizer

22 — Porge Operatirrg Switch

23 24 25 26 27 28 23 30 ~

31 -

32 -

33 ~

Fig. 1 — 19CB Machine Components (R-114 Unit Shown)

P'orge Conderising Chamber

Riiter-Drier Shetoff Valve Chilled Water Low-Temp Cutout Chi lied Watsr Terr^p P: obe

Purge Refrigerant Level Sight Giass

Purge Water Level Sight Glass Purge Water Drain Valve

Rupture Disc Assembly

Economizer Pioat Valve

Moisture Indicator

Pilter-Drier

Page 3

pressure cylinder. Never apply full cylinder pressure to the pressurizing line. Follow steps 2 thru 5 in proper sequence.

2. Open cooler charging valve fully.

3. Open cylinder regulating valve slowly.

4 Observe cooler or condenser pressure gage and

close cylinder regulating valve when pressure reaches test pressure listed in Table 1.

Do not exceed test pressure!

5. Close cooler charging valve. Remove copper tube.

R-11 machines may be pressurized with the purge pump. Ensure that electrical supply to purge pump is 120 volts. Then follow Operation 3 on the

purge valve chart.

R-1 14 machines may be pressurized with the pumpout unit This method is detailed in the section entitled Pumpout Procedures.

Table 1 — Test Pressures

1 Serial Numlser idenritica-

Tior> Piste

2 Oil C^iarairvg Valve 3 Gii Heater Tl>erfr;ost3t 4 Oil Heater ; ern-.inal Sox 5 Oil Reservoir Siijf.t Glass

6 Oil-Pressare Regtila-rioó

Valve. : :

7 Oil Purtiii Temrinal Sox 8 •'!=•■ Solenoid Valve

9 "G" Soteooici Vaive

tO Gii Cooler

Water-Ir, Conr>..Solenoid

Valve and Plue Cook

12 Oli-Pressore Gage 13 OiPPrsssure Oiilerenrial

Switoli

14 Bearing Temperature Gage 15 Oli XemperaTure Gage

Fig. 2 — Compressor (Electronic Capacity Control)

Machine Tightness — If machine leak testing and

16 Oit Cooler Wa‘-:-r-Oor

Gconeotion

17 Oil Pornp Nciirrepiate 18 Gornoressor Nameplate

19 edmpt esser Joriction Sox

20 Economlter inlet 21 Compressor Morof Terminai

Sox (Par side on most ■ : rncdetsl: r:'.

22 Motor and Stg H i-Temp-

C'-itout iluncticrn Sox ;

23Main Searing inspection Cove'

24 EeonomiKer Darooer Ccn-

r.ection .CR 014 dniy}■ T

25 Guide yiane indicator

{gleotronte ConTrot) : : 26 Hydrau lic V-ane Motcir 27 Oispharoe StuOouT- : 28 DiscP-aige Pipe

dehydration was not completed at installation, check machine tightness (including pumpout sys tem) as described below. Dehydration must be repeated if machine has been idle for several weeks after initial dehydration.

Check for Large Leaks — Using one of the methods

described below, pressurize the machine to the level listed in Table 1. Do not exceed test pressure Listen for large leaks as the pressure builds up. If test pressure holds for one hour, proceed with Check for Small Leaks.

All 19CB machines may be pressurized with

cylinders of dry air or nitrogen thni the cooler

charging valve. Dry air or nitrogen charging is preferable to purge or pumpout charging as it ensures that moisture will not be introduced into the machine. To pressurize with nitrogen (or dry air):

1. Connect a copper tube from charging valve to

REFRIGERANT

R-11 R-114

Check for Small Leaks

TEST

PRESSURE

8-10 psig

30 - 35 psig

1. Pull a vacuum equal to 5 in. Hg (12 5 psia) by using purge pump Operation 2 (R-11 machines), pumpout unit (R-114 machines) or

by applying a vacuum pump at the cooler charging valve.

2. Charge approximately 25 pounds of the proper

refrigerant thru the cooler cliarging valve.

Pressurize machine to test pressure (Table 1) using purge pump, pumpout unit, dry air or

nitrogen. Do not exceed test pressure Test all joints, valves, fittings etc. with a halide

4. or electronic leak detector.

Check Leakage Rate

1 Install a mercury manometer (absolute pressure

type) on a tee at the cooler charging valve.

Pull 25 in. of vacuum on the machine.

Let machine stand with this vacuum for at least

8 hours If leakage rate is less than 0.1 in. Hg in 24 hours

(0.033 in. Hg in 8 hrs), machine is sufficiently tight. Perform Machine Dehydration.

If leakage rate exceeds 0.1 in. Hg per 24 hours,

repeat Check for Small Leaks, repair leaks and

repeat this Leakage Rate check.

Remove or valve off manometer before re

peating any pressure test.

Machine Dehydration

W.^iRNlNG: Do not attempt to start compres sor, oil pump or purge motor even fox a rotation check, nor app.ly test voltage of any kind while machine is under dehydration vacuum- Motor insuiation breakdown and serious damage tnav result.

Page 4

Fig. 3 — Pumpout System Schematic (R-114 Units)

SEPARABLE UNION

PIPING BY CARRIER FIELD PIPING

1. Connect dehydration pump to cooler charging valve.

2. Ensure that all valves on purge assembly are closed; valves on filter-drier system open.

3. Install mercury manometer (absolute pressure type) at charging valve.

4. Operate pump until manometer reads 0.20 in. Hg absolute. Continue to operate pump for 2 more hours.

5. Close cooler charging valve; stop pump; record manometer reading.

6. Wait 2 hours and read manometer again. If ab solute pressure reading has not increased, dehy dration is complete. If absolute pressure has increased, repeat steps 4, 5 and 6.

7. If vacuum fails to hold after several dehy dration attempts, check for machine leak by repeating the (?heck for Small Leaks.

Pumpout Procedures (R-114 Units)

MACHINE EVACUATION (No refrigerant in system)

1. Set purge valves per Operation 5 on purge valve operation plate.

2. Jumper low-pressure cutout on pumpout compressor.

3. Close valves 1, 3, 7 and 10.

4. Open valves 2, 4, 5, 6, 8, 9 and 11

5. Disconnect separable union between pumpout condenser and oil separator.

6. Run pumpout compressor until desired machine vacuum is reached.

7. Close valve 5 and reassemble union.

8. Stop compressor.

9. Remove jumper.

PRESSURIZING THE MACHINE (No refrigerant in system)

1. Set purge valves per Operation 4 on purge valve operation plate.

2. Close valves 2, 4 and 10.

3. Open valves 1, 3, 5, 6, 7, 8, 9 and 1 1.

4. Disconnect separable union in pumpout com pressor suction Hne.

Operate pumpout compressor until desired pressure is reached. Do not exceed test pressure

listed in Table 1.

6. Shut off pumpout compressor

7. Reassemble union.

8. Return purge valves to “Normal-Auto” condi tion when pressurizing is completed.

Oil Charge — Use oil shipped with machine. This

oil conforms to Carrier’s oil specifications for hermetic centrifugal compressors.

Charge oil thru the oil reservoir charging valve.

Machine vacuum will draw the oil from the

container. Add oil until it reaches the middle of the oil sight glass. After charging, close valve completely to prevent air from entering machine. R-114 machines containing refrigerant will require a small hand pump for oil charging.

On pneumatic machines, add oil to the vane seal chamber thru pipe plug opening (see Fig. 4) until level reaches bottom of rack and gear as seen thru Plexiglas cover.

Oil Heater — Check for 1 20 volt supply. Energize

oil heater to minimize oil-refrigerant absorption. A

light indicates when the heater is energized. The oil heater thermostat is set to maintain a temperature of 140 F ± 3 F at shutdown. Adjust if required.

Fig. 4 — Pneumatic Vane Shaft Seal Chamber

Page 5

Refrigerant Charge

1. Install a charging valve in the 3/4-in. drum opening as shown in Fig. 5.

Fig. 5 — Drum Charging Valve

Chilled water should enter the lower nozzle of the cooler and leave at the upper nozzle. Chilled water temperature probe should be installed in leaving chilled water hue.

Condenser water should enter the upper con denser nozzle and leave at the lower.

Insure that pipes are vented and properly suspended, with no stress on nozzles or on water box covers.

Check to see that water flow agrees with design flow. Pressure drop measurements across cooler and condenser or across the pumps will indicate approximate flow rate.

Oil cooler water must be clean, with 85 F maximum temperature and 200 psi maximum inlet pressure. Refer to tag attached to the inlet line for pressure drop and velocity limits.

Field Wiring

Connect a short length of plastic hose or copper tubing from drum valve to cooler charging

valve. Circulate chilled water during the charging

3. process.

At a pressure less than that indicated in Table

4. 2, liquid refrigerant will flash into gas and may cause tube freeze-up. Keep refrigerant drum upright and admit refrigerant as a gas until cooler pressure is greater (smaller value of in. of mercury vacuum) than that listed in Table 2.

Table 2 — Pressures Corresponding to 32 F

Saturation Temperature

REFRIGERANT

R-11

R-114

PRESSURE - INCHES

OF MERCURY VACUUM

18 05

3 85

5 The refrigerant supplied with the machine is in

excess of the amount required for initial charg ing. Charge the amount shown in Table 3, less

200 pounds

6. After the machine has been started, it may be necessary to adjust the charge for optimum machine performance. For this adjustment, see Trimming Refrigerant Charge.

Table 3 — Refrigerant Shipping Charges

MACHINE SIZE

Model Heat Exch

No. ^ Combn*

19CB1200 19CB1300 19CB33-36 R-11 19CB1400 19CB1500 19CB1600

19CB1800 19CB2000

*First 6 digits of 1 0-digit Machine Model code

Inspect Piping

19CB33-36

19CB43-46 R-11 19CB53-56 19CB64-66 R-11

19CB77-78 R-114 19CB87-88 R-114

REFRIG

R-11 3200

R-11 3750

SHIPPING

CHARGE

3200 3750

4000 5400

5400

Refer to piping diagrams provided in Job Data and inspect piping to cooler, condenser and oil cooler.

WARNING: Do not attempt to check high

voltage supply without proper equipment. Serious personal injury' cajr result.

Refer to Job Data wiring diagrams and check

field wiring as follows:

1. Connect voltmeter across incoming power wires to compressor motor starter. Compare the reading with voltage ratings on compressor and starter nameplates.

2. Check that amperage rating on starter name plate matches full load amperage rating on compressor motor nameplate.

3. Ensure that voltage to oil pump starter agrees with oil pump nameplate value.

4. Ensure that pumpout compressor voltage ^sup ply agrees with motor nameplate.

5. Check that electrical supply to purge pump (R-11) is 120 volts.

6. Test compressor motor and motor power lead insulation resistance with a 500 volt insulation tester such as a megohmmeter.

a Open starter nmin disconnect switch.

b. With tester connected to the motor side of

the starter contactor in the starter, take 60-second and 10-second megohm readings as follows’ Six lead motor — Tie all 6 terminals together and test between terminal group and ground.

Next, tie terminals in pairs, 1 and 4, 2 and 5,

3 and 6. Test between each pair while

grounding the third pair. Three lead motor — Tie terminals 1,2 and 3

together. Test between terminal group and ground.

c. Divide the 60-second resistance reading by

the 10-second reading. This ratio, or polar

ization index, must be 1.15:1 or higher. Both the 10-second and 60-second reading must be at least 5.0 megohms. If the readings are unsatisfactory, repeat the test at the motor terminals with power leads disconnected. Satisfactory readings in this second test indicate that the fault is in the

motor leads.

Page 6

Check Starter — Before starting the 19CB machine,

open the main disconnect and check starter.

1. Remove contactor arc chutes. Be sure con tactors move freely and that shipping string has been removed. Replaee arc chutes.

2. Check contactors for dirt and rust. Clean contact magnet surfaces lightly with sandpaper. Do not sandpaper or file silverplated contacts. Apply a very thin coat of petroleum jelly to magnet surfaces and then wipe it off. If starter has been in a dusty atmosphere, vacuum clean the cabinet and wipe with hnt-free cloth.

3. Remove fluid cups from magnetic overload relays. Add dashpot oil to cups per instructions on relay nameplate. Oil is slripped in small vials usually attached to starter frame near the relays. Use only dashpot oil supplied with starter. Do not substitute. Overload relays are factory set for 108% of motor full load amperage. Resetting is not normally required, nor is it recommended except by a qualified electrical shop.

4. Check transfer timer for proper setting. On

Star-Delta starter, timers have adjustable range

of 10 seconds to 3 minutes and are factory set

for 1 minute. Auto.-Transformer timers have adjustable range of 1 to 60 seconds and are factory set at 30 seconds.

5. With main disconnect open, manually open and

close the main control relay (ICR) to be sure it operates freely.

Check Operation of Safety Controls — As the

following checks are made, control panel lights should appear as indicated in the diagrams.

OFF ON

□

1. Open main disconnect (all

power off to starter and controls). Disconnect main motor leads in starter.

2. Provide control circuit power from separate

115-volt source.

3. Press ON-STOP button (light goes on). If

STOP

POUVER SAFETY LOAD

□

STOP

POWER SAFETY LOAD

■ □ n

STOP

CIRCUIT RECYCLE

■

CIRCUIT RECYCLE

□ □

START OIL

□ □

□ □ n

PROGRAM

□

START OIL

PROGRAM

START OIL

PUMP

TIMER

□

PUMP

TIMER

PUMP

SAFETY CIRCUIT light does not go on, check resets on condenser high-

■ ■ ■ n

SAFETY LOAD

POWER

CIRCUIT RECYCLE

PROGRAM

TIMER

pressure safety, low-refrigerant temperature safety, bearing and motor Ihgh-temperature circuit breakers and compressor overloads in starter. Check 3-amp fuse in control center.

If SAFETY CIRCUIT light goes on but LOAD RECYCLE light stays off, check the chilled water recycle switch (auto-reset).

If both lights go on, manually trip and reset motor and bearing high-temperature circuit breakers, compressor motor overloads in starter, and low-refrigerant temperature cutout to be sure they cut off the safety light.

Tripping the chilled water recycle switch will

cut off the LOAD RECYCLE light only.

ELECTRONIC CONTROL PNEUMATIC CONTROL

Fig. 6 — Control Center Components

4. Press ON-STOP button (light goes out). Remove and tag gray striped wire

from control center

□ □

START OIL

STOP

■ □ □ n

POWER SAFETY LOAD

CIRCUIT'RECYCLE

terminal

5. Start chilled water and

condenser water pumps. Press ON-STOP button (light goes on).

6. Press OIL PUMP button for several seconds. Pump

■

STOP

□

START

■

□ □ n

POWER SAFETY LOAD

CIRCUIT RECYCLE

■ □

START

STOP

should raise oil pressure

■

16 - 18 psi above refrig

erant pressure at machine

POWER

■ ■ n

SAFETY LOAD CIRCUIT RECYCLE

shutdown condition. SAFETY CIRCUIT and

LOAD RECYCLE lights should go on.

7. Release OIL PUMP button. SAFETY CIR CUIT light and LOAD RECYCLE light should go

out.

■ □ n

START OIL

STOP

□ □

■

SAFETY LOAD

POWER

CIRCUIT RECYCLE

□

PUMP

PROGRAM

TIMER

□

PUMP

PROGRAM

TIMER

■

PUMP

PROGRAM

TIMER

PUMP

PROGRAM

TIMER

OIL

Page 7

With OIL PUMP button depressed, alternately stop and restart chilled water and condenser water pumps. SAFETY

■ □ ■

START OIL

STOP

■

POWER

□ □

SAFETY LOAD CIRCUIT RECYCLE

PROGRAM

TIMER

PUMP

CIRCUIT and LOAD RECYCLE lights should go out as each pump stops. (Continuous operation of oil pump is unnecessary during these checks.)

9. Shut off water pumps. Release OIL PUMP button.

□ □ □

ON START OIL

STOP PUMP

Press ON-STOP button (light goes out). Replace tagged wire on terminal

(L),

10. Press ON-STOP button (light goes on).

11. Press machine START

button (motor leads disconnected).

■ □ □ □

POWER SAFETY LOAO PROGRAM

CIRCUIT RECYCLE TIMER

■ □ □

ON START OIL

STOP PUMP

■ ■ ■ □

POWER SAFETY LOAD PROGRAM

CIRCUIT RECYCLE TIMER

■ ■ □

■

POWER

START

■ ■

SAFETY LOAD CIRCUIT RECYCLE

■

PROGRAM

TIMER

STOP

OIL

PUMP

Oil pump starts within 30 seconds.

Compressor motor start contacts will close 30 seconds later. Starter will transfer to its run condi tion 30 to 60 seconds

■ ■ ■

■

START OIL

■ ■

CIRCUIT RECYCLE

PUMP

PROGRAM

TIMER

STOP

POWER SAFETY LOAD

after starter is energized.

12. Open oil pump main dis connect. Starter must de energize. OIL PUMP light will remain on for approx imately 5 minutes.

OIL PUMP light goes out.

13. Close oil pump dis connect. In approximately

10 minutes the program timer will complete the antirecycle portion of its

■

STOP

POWER

□ ■

START

■

□ □ ■

SAFETY LOAO CIRCUIT RECYCLE

■

STOP

POWER SAFETY LOAO

■

STOP

POWER

□

START

■ □ □ ■

CIRCUIT RECYCLE

□ □

START OIL

■

■ ■ n

SAFETY LOAO CIRCUIT RECYCLE

OIL

PUNIP

PROGRAM

TIMER

OIL

PUMP

PROGRAM

TIMER

PUMP

PROGRAM

TIMER

cycle and machine is ready to restart. (Total recycle time — 15 minutes.)

14. Remove all power. Reconnect motor leads. Restore power.

Purge — Place the purge operating valves (Fig. 1) in

“Normal-Automatic” position as indicated in Oper ation no. 1 on the purge valve operation plate. Operate the purge momentarily by placing the purge switch in “Manual” position; then place purge switch in “Auto.” position.

Air Supply (Pneumatic Controls Only) — Check 25

psi air supply to pneumatic temperature controller and pilot positioner.

START-UP

Before Starting Machine — Be sure that-

Power switch is on to circuit breakers, water pumps, tower fan and control circuit.

Cooling tower water is at proper level. Oil is visible in reservoir sight glass. Oil reservoir temperature is 140 F or warmer. Oil cooler plug cock is cracked open and any other

valve in the oil cooler line is fully open. Refrigerant is at selected design level. Valves in cooler and condenser water circuits are open Do not permit water above 100 F to flow thru

cooler

Filter-drier shutoff valves (Item 24, Fig. 1) are open. Air supply for pneumatic controls is adequate

COMPRESSOR ROTATION - Electronic Control: Set capacity control switch on “Hold.”

Pneumatic Capacity Control: Turn off supply air to chilled water thermostat and vane positioner.

Press machine ON-STOP and START buttons. As soon as motor begins to turn, press machine ON-STOP button. Check motor rotation thru sight glass on motor end bell. Motor rotation must be counterclockwise as viewed thru sight glass.

COMPRESSOR OPERATION — Press machine ON-STOP and START buttons and let compressor come up to speed. Press machine ON-STOP button and listen for any unusual sounds from compressor as it coasts to a stop.

The program timer prevents rapid recycling and

allows compressor restart 15 minutes after stop.

Checking Safety Control Settings

■While performiiig these checks, carefully moni tor cMlied -vt'ateT temperature to prevent freeze>-up. Protection by safety controls cannot be assumed until all settings have been con

firmed as follows:

Open main disconnect (all power off to starter and controls).

Electronic Control: Set capacity control switch on

“Hold.”

Pneumatic Control: Ensure that pilot positioner operates as described in Setting Operating Controls-Pneumatic. Then set percent load

Page 8

knob on demand limit control at 100% and turn

calibration screw fully clockwise.

Place a clamp-on ammeter on one of the 3 starter leads. Be sure ammeter scale is set so that compressor full load amperage will register be tween midway and just under the top of the scale.

Install jumpers between ^ and [^, and

between and 11

Close disconnects, start

Table 4 — Setting Safety Controls

compressor and check oil pressure and temperature (Fig. 2). With compressor running, operate the guide vanes with capacity control switch or pneu matic thermostat. Do not exceed 100% full load

amps.

1. Check controls 1 and 2 as indicated in Table 4.

2. Stop machine, open disconnects, remove jumpers and check controls 3, 4 and 5 as

indicated.

SAFETY OR CONTROL DEVICE

1. Chilled Water Low-Temperature Cutout and Recycle Switch

(Fig. 1)

'TEMPERATURE AD.IUSTMENl

^ O,

DIFFERENTIAL ADJUSTMENT

JZ, —’ ''Bi*

Set this switch to break at approximately 5 F below design chilled water temperature, or at 36 F whichever is higher

Set the differential at 10 ± 1 F so that when the machine shuts down automatically at approximately 5 F below the design

chilled water temperature it will restart at approximately 5 F above the design water temperature.

This control must break ahead of the refrigerant low-

temperature cutout switch or the machine will not recycle automatically

SAFETY OR CONTROL DEVICE

STOP MACHINE, REMOVE JUMPERS AND PEREORM RE

MAINING CHECKS.

3. Condenser High-Pressure Cutout (Fig. 6)

CUTOUT ADJUSTMENT .f.'

COVER

RESET BUTTON

CUTOUT SCALE

The condenser high-pressute cutout is factory set to shut the

machine down when condenser pressure reaches setting listed.

Isolate the switch and check setting with a metered supply of air

JiEFRlG

114

SETTING

15 psig

45 psig

2. Refrigerant Low-Temperature Cutout (Fig. 6)

CUTOUT

ADJUSTMENT

Set refrigerant low-temperature cutout at 33 F or one degree below design refrigerant temperature, whichever is lower, while checking temperature at thermowell near control center

4. Oil Heater Thermostat (Fig. 2)

Set the oil heater thermostat to maintain a minimum oil reservoir temperature of 140 F at shutdown.

Page 9

Table 4 — Setting Safety Controls (contd)

SAFETY OR CONTROL DEVICE

5. Low Oil Pressure Cutout (Fig, 2)

RESERVOIR

PRESSURE-:^,

RANGE ^ DIAL ADJUSTMENT, REMOVE METAL

COVER

DIFFERENTIAL-

OIL

PRESSURE

Low oil differential pressure switch is factory set to open at 5 5 ± 1

psi and close at 12 5 ± 1 psi differential pressure Operate oil pump

manually Remove cap and gasket from regulating valve and loosen locknut Turn adjusting screw counterclockwise to lower oil pressure to 5 psi differential If safety does not trip, turn range dial

clockwise until cutout occurs

6. Oil-Pressure Regulating Valve (Item 6, Fig 2).

REFRIG

^ R- Vl

R-114

^Settings given are above

reservoir pressure

SEALING

GASKET'

Remove cap and washer and loosen locknut Turn adjusting screw clockwise to raise oil pressure

SETTING*

1 5 psid

15-20 psid

SAFETY OR CONTROL DEVICE

7. Vane Speed Valve (Electronic Machine Only)

Angle valve is located between oil line to main bearing and "F" and "G" solenoid valves (Items 8 and 9, Fig 2) Set valve at full open position

8. Chilled Water Flow Switch

Field supplied and ir-rstalled Follow switch manufacturer's instruc tions for adjustment and maintenance

9. Main Bearing Oil Temperature (Item 14, Fig. 2).

During machine operation, gage should read 145-160 F Adjust water flow thnr oil cooler with plug cock (item 11, Fig. 2) Do not exceed 7 gpm or pressure drop of 5 psi Do not exceed 200 psig working pressure

10. Dual Pressurestat for R-114 Pump-Down Compressor

COVER

LOW-PRESSURE

SWITCH

COMPRESSOR

CONNECTIONS'

High-pressure switch to open on rise at 45 0 psig Low-pressure switch to open on fall at 2 0 in Hg vacuum

Set high-pressure switch by operating compressor and throttling pump-down condenser water while watching pressure gage

Set low-pressure switch by operating compressor and gradually shutting suction valve while watching pressure gage

CUTOUT AND

CUT-IN PRESSURE

ADJUSTMENT

HIGH-

PRESSURE

SWITCH

CUT-IN

PRESSURE

'ADJUSTMENT ONLY

CUTOUT PRESSURE ADJUSTMENT ONLY

Setting Operating Controls — Electronic

MOTOR CURRENT CATIBRATION (Electronic Capacity Control)

1. Establish a steady motor current value for this calibration. Open guide vanes manually (capacity control to “Inc”) until full load current is reached. Motor current calibration (Fig. 7) may need to be turned counterclock

wise to permit vanes to open further. Do not

exceed 105% of nameplate full load amperes.

If system load is sufficient to maintain full load current for a period of time, calibrate at this condition. With small loads, pull down to and maintain design leaving chilled water temperature (capacity control at “Hold”) and

calibrate at this condition.

2. Measure motor current at selected condition.

Determine its percentage of full load motor current.

3. Use this percentage figure to set the electrical

demand adjustment (Fig. 7) per the following table:

Percent of Full

Load Motor Current

105

85 or above 65 to 84 45 to 64 below 45

Electrical Demand

Adjustment Setting

100%

80% 60%

40% Control cannot be calibrated

4. Turn the motor current cahbration adjustment fully clockwise. The guide vanes will close part way.

5. Turn the thermostat adjustment (Fig. 7) to “Cooler” (fully counterclockwise).

6. Set capacity control at “Inc 7

Slowly turn the motor current calibration

position.

counterclockwise. Allow the guide vanes to open until motor current reaches 5% above the electrical demand setting.

NOTE: There is a time lag of several seconds due to feedback capacitance in the motor current circuit. When the motor current cali bration setting is adjusted, allow for this time lag.

Page 10

• ^^>4-iXwCr.- ••VJ 'ava>

; «O*«®

Fig. 7 — Capacity Control Module

(Electronic Control)

The electrical demand adjustment permits the operator to set the maximum current drawn by the motor and thus minimize the electrical demand rate during off-season operation.

CHILLED WATER CALIBRATION (Electronic Controls)

1. Turn throttle range adjustment (Fig. 7) fully clockwise.

2. Turn chilled water thermostat until design chilled water temperature is maintained. Mark

thermostat at this position. If capacity control

vanes hunt, turn throttle range adjustment

counterclockwise in small increments until

hunting ceases. Chilled water thermostat may require resetting.

Setting Operating Controls — Pneumatic Capacity Control

PILOT POSITIONER

Check the foregoing motor current calibrations with machine under “Auto.” control as follows'

Close vanes manually (capacity control to

“Dec”).

Turn capacity control to “Auto.” Vanes

should stop opening at electrical demand

setting.

control was calibrated at less than 100%

9. If load, turn electrical demand adjustment setting to 100%. Control is now automatically cali brated for 100% full load current.

10. If control cannot be calibrated with above procedure, check voltage signal from signal resistor in starter. At 100% full load current, voltage between terminals 23 and 24 inside control center must be 0.5 ±0.1 volts. If not in this range, check sizing of resistor in starter.

Both excess motor current and chilled water

temperatures below the thermostat set point (Fig.

7) will override the capacity control setting. If the capacity control knob is in the “Inc” position, the guide vanes will stop opening. With the knob in any of the other positions, the vanes will close as needed.

The motor current hmiting circuit operates in

2 steps.

At 100% full load motor current, the vanes

will stop opening further. If the motor current

should increase to 105% due to some change in

load conditions, the vanes will close until the

motor current is reduced to about 102%.

If the motor current is reduced to 98% or

below, control again operates in response to chilled

water temperature.

ITEM DESCRIPTION

1 MAIN AIR CONNECTION (25 PSIG)

2 STARTING POINT ADJUSTMENT NUT 3 LEVER ARM 4 FOLLOWER SPRING

5 PILOT AIR CONNECTION

(FROM CONTROL CENTER)

Preparation: a. Place jumper between field wiring terminal

and load limiting module terminal*^.

b. Open 25 lb air supply valve. c. Remove cover from pilot positioner.

Calibration:

Rotate dial on chilled water thermostat to vary pilot pressure. Observe pressure gage in pilot supply line near pilot positioner and adjust starting point nut (2) until piston operator begins to move at 5 psi pilot pressure. Place follower spring (4) in proper hole in level arm so that piston operator opens 100% at 15 psi pilot pressure.

Completion:

Remove jumper from terminals and Replace cover.

Page 11

ELECTRO-PNEUMATIC RELAY

LOCKNUTS SENSITIVITY SCREW

^SET POINT SCREW

COVER

CONTROL AIR

(OUTPUT)

This control is factory calibrated to provide a linear output signal of 3 psi at 6 volts d-c to 18 psi at 15 volts d-c. Field recaHbration should not be necessary.

If calibration is required:

1. Establish 15 volt d-c input with 25 psi supply air.

2. Turn sensitivity screw to obtain 18 psi or higher

output.

3. Adjust setpoint screw, if required, to set output at \ 8 ±V4 psi.

4. Reduce input to 6 volts. Output should be 3 ± V4 psi. If low, turn sensitivity screw carefully clockwise. If high, turn screw counterclockwise.

5. Recheck output at 15 volts. Repeat steps 3 and 4 if necessary.

DEMAND LIMIT CONTROL

CALIBRATION ADJUSTMENT

COVER

1. Set percent load dial at 100%.

2. Set band width dial at 3.

3. Turn the cahbration adjustment screw fully clockwise.

4. Run machine at 100% FLA by adjusting dial on chilled water thermostat.

5. Turn calibration adjustment screw counter clockwise until guide vanes just begin to close.

6. If hunting occurs, increase bandwidth and re peat steps 4 and 5.

7. If control cannot be calibrated with above procedure, check voltage signal from resistor in starter. At 100% full load, voltage between termmals 23 and 24 inside control center must

be 3.0 ± 0.1 volts. If not in this range, check siz ing of resistor in starter.

CHILLED WATER THERMOSTAT (Pneumatic)

HIDDEN

ITEM

3 4 5

SET POINT ADJUSTING SCREW THERMOSTAT DIAL SENSITIVITY SLIDER SUPPLY AIR PRESSURE GAGE SUPPLY AIR CONNECTIONS CONTROL AIR PRESSURE GAGE CONTROL AIR CONNECTIONS

DESCRIPTION

Preparation:

1. Ensure 25 psi supply air to thermostat.

2. Loosen Allen setscrew in sensitivity slider and move slider halfway between midpoint and DA.

Retighten screw.

Calibration:

1. Turn thermostat dial until control air registers 15 psi.

2. Operate machine to reach design chilled water temperature at design load. Maintain 15 psi control air during pulldown by adjusting ther mostat dial as required.

3. On reaching design chilled water temperature, turn dial until control air pressure holds

machine at design conditions.

4. Hold set-point adjusting screw stationary within the dial post and set the thermostat dial at de sign chilled water temperature.

Completion:

If vane hunting occurs, move sensitivity slider away from DA. Throttle range may be narrowed or widened by moving slider between the limits of 0.1 psi/F at midpoint to 5 psi/F at DA.

Page 12

FINAL MACHINE ADJUSTMENT

Trimming Refrigerant Charge — After the macliine

has been placed in operation, it may be necessary to adjust the refrigerant charge to obtain optimum machine performance.

When machine full load is available, using the extra 200 pounds of refrigerant, add refrigerant slowly until the difference between the leaving chilled water temperature and the cooler tempera ture reaches design conditions or becomes a minimum. Shut the machine down and allow refrigerant to drain to the cooler, mark the level indicator and maintain that shutdown refrigerant level.

INSTRUCTING THE CUSTOMER OPERATOR

Be sure the operator carefully reads and under stands the I9CB Operating and Maintenance Instructions.

Point out the following machine components, explain their function and that of the system in

which they are used.

1. Compressor—Motor Assembly

a. Guide Vanes, Vane Positioner

b. Refrigerant-Cooled Motor

2. Cooler-Condenser-Economizer

a. Float Chamber, Sight Glasses

b. Thermowells

c. Rupture Disc

d. Refrigerant Charging Valve

3. Purge System

a. Importance of proper operation

b. Valves and System Operation

c. Sight Glasses, Gage

5. Lubrication System

a. Oil Pump, Cooler, Filter b. Solenoid Valve, Plug Cock c. Heater, Thermostat, Temperature Gage d. Pressure Regulating Valve e. Oil Level, Temperature

6. Control System

a. Manual Switches (ON-STOP, START, OIL-

PUMP) b. Gages and Lights c. Safety Controls d. Operating Controls e. Auxiliary and Special Controls

7. Auxiliary Equipment

a. Starter(s) b. Pumps c. Cooling Tower d. Pumpout System (where applicable)

Describe Refrigeration Cycle

Review Maintenance

1. Scheduled

2 Extended Shutdown 3 Importance of Log Sheet 4 Importance of Water Treatment

Check Operator Knowledge

1. Start-Stop Procedure 2 Safety and Operating Controls

Discuss Carrier Service

1. Availability

2. Method of Ordering Parts

Review Operating and Maintenance Instructions

4. Filter-Drier System

a. Cartridge Removal b Moisture Indicator Check

c. Shutoff Valve Function

For replacement items use Carrier Specified Parts. k

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

Carrier Air Conditioning Company • Syracuse, New York

Tab 15 Foim 19CB-2SS Supeisedes 19CBUSS

Printed in U S A

10^73

Codes MA and ML

Catalog No 531-942