Carrier 19DG User Manual

Carrier

initiai Start-Up Instructions

Heritìetic Cpfìtrifugal Liguid Chillers

INTRODUCTION

All persons involved in start-up and operation of the 19DG Machine should understand these instructions and all applicable Job Data before initial start-up. The instructions are arranged in the proper sequence for machine start-up.

Job Data Required

1. Machine assembly, wiring and piping prints.

2. Starter details

3. 19DG Installation Instructions

4. 19DG Operating and Maintenance Ins

Equipment Required

1. Mechanic’s tools

Volt-ohmmeter and clamp

Manometer, absolute pressu'

Leak detector, halide or el№tf^ic

Refrigerant drum charging valve (F

5/8-in. SAE X 3/4-in. MPT ada rter

Five to ten ft of copper tub!

to fit 5/8-in. SAE connection;

INITIAL PREPIAR

CAUTION; Do not síai^iítempressor or oil pump, even for a rotation check, unless compressor has been charged with oil and machine charged with refrigerant.

Machine Tightness — A shipping vacuum was

applied to the refrigerant side of the 19DG

Machine before shipment from the factory. Over a

period of time, during shipment or storage, part of

this vacuum may be lost. The loss of a small

amount of vacuum may be acceptable and within Carrier’s machine tightness standards. To deter mine if the vacuum loss is acceptable;

1. Record and date vacuum reading shown on the compressor-mounted oil reservoir gage (Eig. 1).

2. Determine vacuum leak rate by comparing this reading with reading taken when machine was received. Use the formula:

^ , vacuum difference Leak rate ==

3. If leak rate is 0.05 in. Hg or less per 24 hours, machine is sufficiently tight. If leak rate exceeds 0.05 in. Hg per 24 hours, perform Refrigerant Pressure Test and correct leakage.

EXCESSIVE OR TOTAL VACUUM LOSS can be

caused by accidental opening of a valve or other connection. If this is suspected, proceed as follows;

1. Install a mercury manometer (absolute pressure type) at the cooler charging valve (Eig. 1). A

-----------------------------------no. of days between readings

plastic hose

)

dial gage leakage act time.\

Pull a\yaci|ium on the machin'd"equal to 25-in.

the leak rate is 0.05 in. Hg or less per 24 hours, the machine is sufficiently tight. Perform Machine Dehydration.

If the leak rate exceeds 0.05 in. Hg per 24 hours, perform Refrigerant Pressure Test and correct leakage. Perform all steps under

Machine Dehydration.

Remove the mercury manometer from cooler charging valve.

REFRIGERANT PRESSURE TEST

Pull a vacuum equal to 5 in. Hg ref 30-in. bar. (12.5 psia) using machine purge pump, and following operation no. 2 described on the purge valve operation plate (Fig. 1). An external vacuum pump connected to the cooler

charging valve may be used, if desired.

2. Charge approximately one gallon of Refrigerant 11 thru the cooler charging valve. Refer to

Charging Refrigerant for procedure.

3. Increase pressure to 8 to 10 psig with dry air or

nitrogen thru the cooler charging valve. Do not

exceed 10 psig.

4. Test all joints, valves, fittings, etc., with a halide

or electronic leak detector.

5. Repair any leaks found. Retest to ensure repair.

MACHINE DEHYDRATION — The refrigerant

side of the 19DG Machine is dehydrated at the factory. It is usually not necessary to repeat dehydration at initial start-up. However, if the

machine has been open for a considerable length of time due to compressor removal, or if there has been excessive loss of shipping vacuum, it is

recommended that dehydration he repeated.

Dehydration is readily accomplished at normal room temperature. If room temperature is high, dehydration takes place more quickly. At low room temperature, dehydration is extremely diffi

cult and special techniques must be applied. Contact your Carrier representative.

Do not start compressor or oil pump even for a rotation check while machine is und.er dehy dration vacuum.

annot indicate the small amot

;eptable during a short p^ridd of

■in. bar. (2.^pS'ia). Use an external mp or enprgize the purge pump (Pig. jratira^Aio. 2 described on the purge

mrfplate (Pig. 1).

e stand with this vacuum for 24

more. Then perform leak rate test

outlined.

2/o7

1 ~ Chiliec! Waier Temperature Probe 2 — Gii Heater Thermoster (l-i:cicter>) 3 — 0!l Heater Indicator Light 4 — Motor Rotation Sight Glasses 5 - Gil Level Sight Glass 6 — Oil Reservoir Pressure Gage 7 — Searing Returr'.-'Gil Temperature Gage 8 — Gil Reservoir Temperature Gage 9— Knockouts lot Field Wiring

10 — Oil Pump Pressure Gage 11 — Refrigerant Level Sight Glasses 12 — Refrigerant Float Charrilaer 13 — Cooler Charging Valve

14 — Purge Water. Level Sight Glass 15— Purge Water Drain Vaive 16 — Purge Pressure Gage 17 — Purge Valve Operation Plats

18 - O i ! Cooler Solenoid Valve and Plug Cock

Fig. 1 — 19DG Machine Components

19 — Lub: ication Assembiv 20 — Oil Charging Valve 21 — Oil Pressure Regulating Vaive

(fsionadjustabie) 22 — Chilled Water Low-Temperature Cutout 23—Refrigerant Low-Temperature Cutout 24 ~ Thermowell 25 — Purge Pump (Hidden) 25 — Purge Gperar ing Valves

Perform dehydration as follows:

1. Connect dehydration pump to the cooler charging valve (Fig. 1).

2. Ensure that all valves on the purge assembly are closed. Valve identification numbers are listed on the purge valve operation plate (Fig. 1).

3. Remove the A-B swing connection (see valve operation plate) and connect a mercury manometer (absolute pressure type) to the bottom common connection.

4. Operate dehydration pump until manometer reads 29.80 in. Hg ref 30-in. bar. (0.1 psia); continue to operate pump for 2 more hours.

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

6. After a 2-hour wait, read manometer again. If reading has not increased, dehydration is com plete. If reading has increased, repeat steps 4

and 5.

7. If reading continues to rise after several dehy dration attempts, check for a machine leak by repeating the Refrigerant Pressure Test.

Inspect Piping — Refer to piping diagrams provided

in Job Data and inspect piping to cooler, condenser and oil cooler. Ensure that flow direction is correct in all cases and that all piping specifications are met.

CHECK WATER ELOW — Water flow thru con denser and cooler must meet job requirements. Measure the water pressure drop across cooler or

condenser or across the pumps. Check to see that water flow agrees with design flow.

Oil cooler water should meet the following

requirements:

Clean water Max water temperature 85 F Max inlet working pressure 200 psi Water vel in tube, ft/sec 10 max — 6 min Water flow, gal./min 7 max — 4 min Water press, drop, psi diff 5 max — 2 min Valves and/or controls Field supplied

Field Wiring — Prior to starting equipment,

refer to wiring diagrams in Job Data and check

power supply as follows:

1. Connect a voltmeter across power wires to compressor motor starter and measure voltage. Compare this reading with voltage rating on compressor and starter nameplates.

WARNING; Do not attempt to check high voltage supply without proper equipment. Serious personal injury can result.

2. Check that ampere rating on starter nameplate matches ampere rating on compressor motor nameplate.

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

4. Check that electrical supply to oil heater and

purge pump is 120 volts.

5. Test compressor motor and its power lead insulation resistance with a 500-volt insulation

tester such as a megohmmeter. Proceed as follows: a. Open starter main disconnect switch. b. Test the three phases of compressor motor,

phase-to-phase and phase-to-ground, with tester connected on the motor side of the starter contactor in the starter. Take a resistance reading at a 10-second interval and at a 60-second interval for each phase.

c. Divide the 60-second resistance reading by

the 10-second reading. This gives the polari zation ratio. The polarization ratio must be

1.15:1 or higher. Both the 10-second and 60-second resistance reading must be 5.0 megohms or higher. If readings are unsatisfactory, repeat tests at motor terminals with motor power leads dis

connected. This will indicate whether fault is

in motor or in motor power leads.

Check Starter — Before starting the 19DG

Machine, open the main disconnect and then check starter.

1. Remove contactor arc chutes. Be sure con tactors move freely, and that shipping string is removed. Replace 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 Unt-free cloth.

3. Remove fluid cups from magnetic overload relays. Add dashpot oil to cups per instructions on relay nameplate. Dashpot oil is shipped in small vials usually attached to starter frame near relays. Use only the dashpot oil shipped with starter. Do not substitute. Overload relays

are factory set for 108% of motor full load amperage and resetting is not normally

required.

4. Check transfer timer for proper time setting.

On Star-Delta starters, timers have adjustable ranges of 10 seconds to 3 minutes and are factory set at one minute. On Auto-

Transformer starters, timers have adjustable

ranges of zero to 60 seconds and are factory set for 30 seconds.

5. With main disconnect switch open, manually

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

Oil Charge — The oil charge is shipped in the oil

reservoir. Check sight glass (Fig. 1) to be certain oil is in the reservoir. If oil must be added, it must meet Carrier’s oil specification as listed in the

19DG Operating and Maintenance Instructions.

Charge oil thru the oil reservoir charging valve (Fig. 1). With machine at vacuum, oil is drawn from the oil container. Continue charging until oil reaches middle of sight glass (Fig. 1).

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