Carrier 07KA User Manual

Carrier

Start-Up and

Service instructions

07KA

Water-Cooled Condensing Units

Table 1 - Physical Data

Fig. 1 - 07KA Water-Cooled Condensing Unit

CONDENSING UNIT 07KA 002 REFRIG CHG* R-22 (lb)

COMPRESSOR

Single-phase 3-phase

Oi 1 Charge! (pt) CONDENSER HIGH PRESSURESTAT

Cutout

Cut-in

Fixed Differential

LOW PRESSURESTAT

Cutout

Cut-in

Fixed Differential

*Factory charge. Refer to Refrigerant Charging, page 3,

for charging details.

tUse Carrier PP-33-2, Texaco Capella B1 or Suniso 3G

Dual Inhibited oil.

NOTE: High and low pressurestats cut-in and cutout points are not adjustable.

2 5

06AD126206AD228

T ube-in-T ube

428 ± 5 psig

320 ± 20 psig

108 psig

30 ± 4 psig

60 ± 15 psig

30 psig

004

3.0

06AC228

Table 2 - Electrical Data (60-Cycle)

COND

UNIT

07KA

002310

004310

004510 NDSV - Nominal Distribution System Voltage (Application Range) Motors and controls will operate satisfactorily 10% above LRA - Locked Rotor Amps FLA - Full Load Amps WSA - Wire Sizing Amps

*Maximum dual element fuse size NOTES: 1 Control circuit voltage is 24 volts on all units

2 Branch circuit wire sizes and corresponding maximum wire lengths tabulated will result in a 1% voltage drop at nameplate

full load amperage

VOLTS

NDSV

PHASE

230

and 10% below Nominal Distribution System Voltage.

230

230 220-

240

LRA

49 0

78 0

53 5 10 3 5 0

FLA

12 0 2 75 15 2 12

17 1

MAX

5 0 21 6 10

WSA

13 1 12

Wire Size

(AWG No)

BRANCH CIRCUIT

Max

Wire

46 10 74

52 8

65 10 103

Wire Size

(AWG No)

Max

Wire

Fuse Amp*

START-UP INSTRUCTIONS

Crankcase heater on 07KA004 should be en ergized a minimum of 4 hours before starting unit. 07KA single-phase units are of split capac itor (PSC) type and require an equalized system pressure to start.

Start Procedure

1. Back-seat (open) liquid and suction line serv ice valves. (When accessory water regulating

valve is used, "crack" liquid line service

valve one-half turn from backseat position.)

Carrier Corporation 1967

Printed in U.S.A.

2. Open water supply valve and allow water to reach condenser. (Water regulating valve re stricts water until unit is operating.) Open condenser water discharge valve (when used).

3. Close disconnects energizing entire system.

4. Set room thermostat to desired temperature.

5. Set room thermostat to "Cool" and fan switch as desired.

Motors and controls will operate satisfactorily

10% above and 10% below nominal distribution system voltage (see Table 2).

5-67 07KA-1SS

COMPRESSOR

When supply voltage is within 10% limit and compressor does not start, give compressor a temporary capacitance boost. Use a start booster assembly.

Run compressor for 10 minutes, then shut off and allow system pressure to equalize. Try re starting without boost capacitor. If after two attemps the compressor does not start, add an accessory start capacitor relay package.

The accessory start relay used with the 06A compressor has a current-limiting device to pro tect the compressor in case of relay malfunction. An open current-limiting device indicates that the relay must be changed.

Compressor Protection - 07KA units have a high

pressurestat located on liquid service valve and a low pressurestat located on suction service valve. (See Table 1 for high and low pressure stat settings.)

Single-phase compressor motors are protected by an internal current temperature-sensitive overload. Three-phase compressors are pro tected by internal thermostat and external current overloads. Internal temperature-sensitive over loads reset automatically when internal motor temperatures drop to a safe level. (Overloads may require up to 30 minutes to reset.)

When an internal overload is suspected of being open, check by using an ohmmeter or con tinuity tester. Refer to the Carrier Standard Serv ice Techniques Manual, Chapter 2 for complete instructions.

Compressor Removal

1. Shut off power to unit. Vent refrigerant to at mosphere or use refrigerant removal methods described in Carrier Standard Service Tech niques Manual, Chapter 1.

2. Remove both unit top cover and wrap-around enclosure.

3. Remove compressor power leads from unit control box and pressure relief plug from suc tion line. Unsweat suction and hot gas lines from compressor.

4. Remove compressor hold-down bolts. Lift compressor out thru top of unit.

REFRIGERANT CHARGING

07KA units contain correct operating charge (Table 1) for complete system when combined with Carrier approved capillary-controlled evap orator sections and with a Carrier accessory precharged tubing package in 10- or 18-ft lengths. Additional charge may be required on other sys tems. Add a crankcase heater to 07KA002 when factory charge is exceeded. (Crankcase heater

available from Carrier Service Parts Center, part no. HT32AZ242.) Do not use condensing unit charge for purging evaporator or tubing systems.

Refer to Carrier Standard Service Techniques Manual, Chapter 1 for system evacuation, de hydration instructions and details of charging methods listed below.

Service valve access cover is provided to accommodate charging lines. Replace cover when finished.

Weight Method - Systems with capillary tube con

trol are recharged by weight only. Refer to Table

1 for correct system charge. Blow any refrig

erant remaining in system before recharging.

When interconnecting tubing is shorter than 10 ft or longer than 18 ft, add (subtract) charge as follows:

3/4 oz per 10 ft of 5/16-in. OD liquid line.

1-1/2 oz per 10 ft of 3/8-in. OD liquid line.

Sight Glass Method - A satisfactory operating

charge for thermal expansion valve controlled systems can be obtained by weighing in the refrig-

erant charge shown in Table 1 for capillary feed coil systems. Then, if liquid line sight glass is not clear, add refrigerant until sight glass clears at an operating condition of between 110 F and 120 F condensing temperature.

For maximum capacity (with thermal expansion valve systems), slightly more charge is required than will be provided by the above procedure. To achieve this optimum charge, proceed as follows:

1. Charge per above.

2. Holding pressure at liquid valve {hy hand throt- tling the condenser water) to a corresponding saturation temperature of approximately 115 F, add refrigerant charge until actual liquid tem perature at this point is approximately 97 F (18 F liquid subcooling).

3. In any case, do not charge system to more than 3 lb for systems with 002 and 003 size coils and

4 lb for systems with 004 and 005 size coils.

CHECKING COMPONENTS

Refer to Carrier Standard Service Techniques Manual, Chapter 2 for complete instructions on checking electrical components.

PUMPDOWN PROCEDURE

07KA units may be pumped down in order to make repairs on low side of system without losing complete refrigerant charge.

1. Attach pressure gage to suction service valve

gage port.

2. Front-seat liquid line valve.

3. Jumper low pressure switch.

4. Start unit and run until the suction pressure

reaches 5 psig. (Should the compressor go off

on internal overload or high pressurestat be

fore suction pressure reaches 5 psig, shut off

suction valve and vent remaining refrigerant.)

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