Heatcraft Refrigeration Products Condensing Units H-IM-CU User Manual

After the installation has been completed, the following points should be 

covered before the system is placed in operation:  

Check all electrical and refrigerant connections.  

 

Be sure they are all tight.
Observe compressor oil level before start-up. The  

 

 

 

oil level should be at or slightly above the 1/4 level    

 

 

of the sight glass. Refer to Table 3 for proper compressor oil.
Remove upper mounting nuts on the compressor feet.  

 

 

Remove the shipping spacers. Install the neoprene washers onto   

 

the compressor feet.  Replace the upper mounting nuts  

 

 

and washers, allowing 1/16" space between the mounting nut    

 

and the neoprene spacer.  
Check high and low pressure controls, pressure regulating valves,  

 

oil pressure safety controls, and all other safety controls, and  

 

 

adjust if necessary.
Check the room thermostat for normal operation  

 

 

 

and adjust.
Wiring diagrams, instruction bulletins, etc. attached to the  

 

 

condensing units should be read and filed for future reference.  
All fan motors should be checked for proper rotation. Fan  

 

 

motor mounts should be carefully checked for tightness and  

 

 

proper alignment.  
Electric and hot gas evaporator fan motors should  

 

 

 

be temporarily wired for continuous operation until    

 

 

the room temperature has stabilized.
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.
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.
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 between 1/4 and bottom of the sight glass.
Make sure all Schrader valve caps are in place and tight.
Make sure ALL service valves are properly back-seated and tighten  

 

valve packing if necessary.

a)

b)

c)

d)

e)

f)

g)

h)

i)

j)

k)

l)
m)

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 required.  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.

Scroll compressor is directional dependent. If noisy, change phase of 

input wiring.