Heatcraft Refrigeration Products 25006801 Manuel D’Utilisation

Refrigeration Charging

1. Install a liquid line drier in the refrigerant supply line between the service gauge and the liquid service port of the

receiver. This extra drier will insure that all refrigerant supplied to the system is clean and dry.

2. When initially charging a system that is in a vacuum, liquid refrigerant can be added directly into the receiver tank

to break the vacuum. Weighing in the charge is recommended with the initial charge

consisting of approximately 2 pounds per system compressor horsepower.

3. Remove the refrigerant drum and connect it to the suction side of the compressor to charge with refrigerant vapor

into the low side of the system until the pressure is above atmospheric.

4. Start the system and finish charging until the sight glass indicates a full charge and the proper amount has been

weighed in (a total of 4 to 5 pounds per system compressor horsepower).

5. If refrigerant must be added to the system through the suction side of the compressor, charge in vapor form only.

Liquid charging must be done in the high side only or with liquid metering devices to protect the compressor.

Check-Out & Start-Up

After the installation has been completed, the following points should be covered before the system is placed in

operation:

(a) Check all electrical and refrigerant connections. Be sure they are all correct and tight.

(b) Check setting of time delay relay for low pressure switch in condensing unit. It should be set at two minutes (the

third marker).

controls and adjust them, if necessary.

(d) Liquid line should always be insulated.

(e) Wiring diagrams, instruction bulletins, etc. attached to the condensing units should be read and filed for future

reference.

(f) All fan motors on air cooled condensers, evaporators, etc. should be checked for proper rotation. Fan motor

mounts should be carefully checked for tightness and proper alignment.

(g) Observe system pressures during charging and initial operation. Do not add oil while the system is short of

refrigerant unless oil level is dangerously low.

(h) Continue charging until system has sufficient refrigerant for proper operation. Do not overcharge. Remember that

bubbles in a sight glass may be caused by a restriction as well as a shortage of refrigerant.

(i) Do not leave unit unattended until the system has reached normal operating conditions and the oil charge has

been properly adjusted to maintain the oil level at the center of the sight glass.

CAUTION: Extreme care must be taken in starting compressors for the first time after system charging. At

this time, all of the oil and most of the refrigerant might be in the compressor creating a condition which

could cause compressor damage due to slugging. Activating the crankcase heater for 24 hours prior to

start-up is recommended. If no crankcase heater is present, then directing a 500 watt heat lamp or other

safe heat source on the lower shell of the compressor for approximately thirty minutes will be beneficial in

eliminating this condition which might never reoccur.