Compressor Unit Leak Check, Maintenance/Service

Section 5 • Maintenance/Service

2.If equipped with equalizing solenoid to control suc- tion by-pass, allow solenoid to remain open until pressures equalize, see Figure 5-1 (2 of 2).

3.Turn motor and oil pump starter disconnect switch- es into the OFF position. Lockout/tagout discon- nect switches.

4.If equipped with manual suction by-pass valve and it is not open, open suction by-pass valve to allow oil separator pressure to vent to low-side system pressure, see Figure 5-1 (1 of 2). Close suction by- pass valve when complete.

5.Isolate the compressor unit by closing all valves to the house system. Lockout/tagout valves.

NOTE

If drain valves are installed on suction and discharge headers, open these valves too to remove build up of liquid during shut-down periods.

6.Open any other valves that may trap liquid. Lockout/ tagout valves.

7.Recover or transfer all gas vapors.

8.Open discharge pressure bleed valve at block and bleed assembly and allow remaining pressure in oil separator to equalize to atmospheric pressure.

9.Servicing the compressor unit can proceed at this point. After servicing, ensure to perform a leak check, see Compressor Unit Leak Check procedure.

Compressor Unit Leak Check

The compressor unit must be checked for leaks after ser- vicing to ensure a tight system.

CAUTION

Do not hydro test compressur unit. Failure to comply

may result in damage to equipment.

1.If servicing the compressor unit was completed, proceed to step 2. Otherwise, isolate the compres- sor unit from the house system, see Compressor Unit Isolation procedure.

2.Slowly pressurize compressor unit through suction oil charging port.

3.Check for leaks.

4.Typically, no evacuation is required for open loop systems. If dry nitrogen was used, it can be bled off to atmosphere.

5.If evacuation is required, evacuate from suction oil charging port.

6.Open all valves previously closed and close all valves previously opened. Remove tags as per the local lockout/tagout procedure.

7.Turn the motor and oil pump disconnect switches to the ON position.

8.The compressor unit can now be started, refer to Start-Up procedure in Section 4.

	Line		Line to
	from Oil
			Suction
	Separator	Solenoid

	Shut-off		Needle
			Valve
Line from Oil Separator	Valve

to Shut-off Valve

Line from Needle

Valve to Suction

Figure 5-1. Suction By-Pass Valve Location (Equalizing Solenoid) (2 of 2)

VSG/VSSG • Installation, Operation and Maintenance Manual •Vilter/Emerson • 35391SSG

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