Heatcraft Refrigeration Products 25000102 AC&R Model Regulators, Troubleshooting Oil System

Installation and Operations Manual

Table 22. AC&R Model Regulators

AC&R	Connection	Operation	Oil Level,
Model		Pressure
	Size		Sight Glass
No.		Diff., psig
S-9010	3 BOLT	5 - 30	1/2
S-9010A	4 BOLT	5 - 30	1/2
S-9015	3/4” NPTF F.	5 - 30	1/2
S-9090	3 BOLT	5 - 90	Adjustable
S-9090A	4 BOLT	5 - 90	Adjustable
S-9110	3 BOLT	5 - 30	1/2
S-9120	3 BOLT	5 - 30	1/4 +
S-9130	3 BOLT	5 - 90	Adjustable
S-9190	3 BOLT	30 - 90	Adjustable

Troubleshooting Oil System

The oil return line should always be checked. Feeling the oil return line and seeing how often it gets hot is the main way to tell if the separator is working properly. It is easier if an oil line sight glass is installed, mainly because if the oil line is hot you don’t know if it is oil or hot gas causing it to be hot. If the oil line cycles between hot and cold at least a few times per hour, the separator is most likely working properly. The float tends to open and feed a few ounces of oil at a time and shut until the oil builds back up. If the oil return is cycling there is no need to drain the separator to look at the float components.

Always check the oil reservoir level during a service call. Oil levels in the reservoir will normally vary during periods of varying loads: compressors shutdown, hot-gas defrost, etc. This is normal, however if the level is consistently low or high, the oil system should be checked thoroughly.

Compressor oil levels can be deceiving. It is sometimes hard to tell if the regulator is feeding oil or if oil is coming down the suction line. If the reservoir has too much pressure, often times this pressure will force oil out of the regulator and show a low level, even though there may be excessive oil in the compressor. Many times the best way to check the oil in the compressor is to shut off the oil feeding to the regulator while the compressor is operating and wait a few minutes. If oil is pushed out of the regulator or trapped in the motor cavity on semi-hermetic models, the compressor will overfill.

The oil line sight glass is a good way to see how the separator is working. Look for movement in the glass. If the separator is not feeding on single or low pressure systems, the sight glass will have little or no movement and normally will appear empty. If the separator is feeding, the sight glass will show a rush of oil and foam past the glass. Most of the time, viewing this sight glass can prevent having to open the system.

To check the oil level in the separator if the separator has a drain, shut off the oil return line to prevent further feeding, pump down the system, shut off the system, evacuate the separator, and drain the oil from the bottom.

The separator should hold the pre-charge amount plus or minus a few ounces during operation. By looking at the amount above or below the pre-charge, any problem with the separator or float can be determined.

Note that there is no way to clean or repair welded oil separators. If it is determined that the float is clogged or otherwise malfunctioning, the entire oil separator must be replaced.

When the refrigerant and/or oil types are changed in a system, there is the potential for leaks around o-ring seals. Most elastomers absorb oil and refrigerant and may swell or shrink when exposed to a new oil or refrigerant. In these cases replace the o-rings and seals in the system as needed.

Liquid Filter-Driers & Suction Filters

A replaceable core liquid filter/drier is supplied as standard on all Rack units and is an option in all other parallel systems. A Schrader type access valve is installed in the flange plate of some models. The liquid cores are always shipped loose for field installation. (See No. 5 of Leak Checking, Evacuation, and Start-up section in this manual).

Table 23. Sporlan Valve Co.

Sporlan	No. Of	Desiccant	# Core
		Volume
Model	Cores		Part No.
		(cu. in.)
C-489-(G)	1	48
C-969-(G)	2	96	RC-4864
C14411-(G)	3	144
			RC-4864-HH
C-19211-(G)	4	192
			RCW-48
C-4021-(G)	4	192
C-4025-(G)	4	192

“G” indicates flange plate supplied with _” FPT

#“RC__” Standard Core, “RC__HH” Burnout Core “RCW_” High Water Capacity

Table 24. Alco Controls

Alco	No. Of	Desiccant	# Core
		Volume
Model	Cores		Part No.
		(cu. in.)
STAS-489-T*	1	48
STAS-969-T	2	96	D-48
STAS-14411-T	3	144	H-48
STAS-19211-T	4	192	UK-48
STAS-19213-T	4	192	W-48
STAS-19217-T	4	192

* “T” indicates Liquid Line Service

#“D” Standard Capacity, “H” High Capacity ”UK” High Capacity, “W” Burnout Block

28 Part # 25000102