Heatcraft Refrigeration Products H-IM-FL1A, Installating And Operation Manual

7

Phase Loss Monitor

The combination phase sequence and loss monitor relay 

protects the system against phase loss (single phasing), phase 

reversal (improper sequence) and low voltage (brownout). 

When phase sequence is correct and full line voltage is present 

on all three phases, the relay is energized as the normal 

condition indicator light glows.
NOTE: If compressor fails to operate and the normal condition 

indicator light on the phase monitor does not glow, then the 

supplied electrical current is not in phase with the monitor. This 

problem is easily corrected by the following steps:

1. 

Turn power off at disconnect switch.

2.  Swap any two of the three power input wires.

3.  Turn power on. Indicator light should glow and 

compressor should start.

4.  Observe motors for correct rotation.

Recommended Refrigerant Piping Practices 

The system as supplied by 

Heatcraft Refrigeration Products

, 

was thoroughly cleaned and dehydrated at the factory. Foreign 

matter may enter the system by way of the evaporator to 

condensing unit piping. Therefore, care must be used during 

installation of the piping to prevent entrance of foreign matter.
Install all refrigeration system components in accordance with 

applicable local and national codes and in conformance with 

good practice required for the proper operation of the system. 
The interconnecting pipe size is not necessarily the same size 

as the stub-out on the condensing unit or the evaporator. 
The following procedures should be followed: 

(a)  Do not leave dehydrated compressors or filter-driers on 

condensing units open to the atmosphere any longer  

than is absolutely necessary. 

(b)  Use only refrigeration grade copper tubing, properly  

sealed against contamination.  

(c)  Suction lines should slope 1/4" per 10 feet towards the 

compressor. 

  (d)  Suitable P-type oil traps should be located at the base of 

each suction riser of four (4) feet or more to enhance oil  

return to the compressor. 

(e)  For desired method of superheat measurement,  

a pressure tap should be installed in each evaporator  

suction line in the proximity of the expansion valve bulb. 

(f) 

When brazing refrigerant lines, an inert gas  should  

be passed through the line at low pressure to  

prevent scaling and oxidation inside the tubing.  

Dry nitrogen is preferred.  

(g)  Use only a suitable silver solder alloy on suction and  

liquid lines. 

(h)  Limit the soldering paste or flux to the minimum  

required to prevent contamination of the solder  

joint internally. Flux only the male portion of the  

connection, never the female. After brazing, remove  

excess flux. 

(i)  If isolation valves are installed at the evaporator, full port 

ball valves should be used.

Figure 4. Example of Pipe Support

Refrigerant Pipe Support

  1.  Normally, any straight run of tubing must be supported  

in at least two locations near each end of the run. Long  

runs require additional supports. The refrigerant lines  

should be supported and fastened properly. As a guide,  

3/8 to 7/8 should be supported every 5 feet; 1-1/8 and  

1-3/8 every 7 feet; and 1-5/8 and 2-1/8 every 9 to 10  

feet. 

2.  When changing directions in a run of tubing, no corner  

should be left unsupported. Supports should be placed a  

maximum of 2 feet in each direction from the corner. 

3.  Piping attached to a vibrating object (such as a  

compressor or compressor base) must be supported  

in such a manner that will not restrict the movement  

of the vibrating object. Rigid mounting will fatigue the  

copper tubing. 

4.  Do not use short radius ells. Short radius elbows have  

points of excessive stress concentration and are subject 

to breakage at these points. 

5.  Thoroughly inspect all piping after the equipment  

is in operation and add supports wherever line vibration  

is significantly greater than most of the other piping. 

Extra supports are relatively inexpensive as compared  

to refrigerant loss.

Figure 5. Condensing Unit / Compressor to Wall Support.