How do I stop my compressor slugging?

The single best device to protect the compressor from slugging and floodback is the suction line accumulator. Accumulators are most often found on low temperature systems, but all refrigeration systems can benefit from this relatively low-cost protective device.

What causes slugging in a compressor?

Slugging can result in broken valves, broken head gaskets, broken connecting rods, and other major compressor damage. Refrigerant-cooled semi-hermetic compressors will often draw liquid from the suction line through hot motor windings in the motor barrel, which will assist in vaporizing any liquid.

How do you prevent flooding and slugging?

How do you prevent flooding and slugging? Keep superheat at proper levels.

What happens when you slug a compressor?

Liquid slugging is the phenomenon of liquid entering the cylinder of a reciprocating compressor, a common cause of failure. Under normal conditions, the intake and output of a compressor cylinder is entirely vapor or gas, when a liquid accumulates at the suction port liquid slugging can occur.

What causes Floodback in compressor?

As a lower amount of liquid refrigerant is required to saturate the oil, the rest of the refrigerant will expand and evaporate into vapor. The sudden expansion of the refrigerant will cause the oil-refrigerant mixture to boil rapidly, generating the excess foaming often associated with compressor floodback.

Compressor - Troubleshooting Weak or Bad Valves

How do you prevent liquid migration?

The only sure solution to avoiding migration is to get rid of all the refrigerant in the evaporator, suction line, and crankcase before the off cycle. This can be accomplished by an automatic pumpdown system. In such a system, a thermostat controlling box temperature is wired in series with a liquid line solenoid.

How can a technician determine if an operating compressor is experiencing Floodback?

How can a technician determine if an operating compressor is experiencing floodback? Check the suction superheat at the suction line entering the compressor. A system operating with a suction line superheat of 5° or less is probably experiencing flooding.

What is the difference between slugging and flooding?

What is the difference between flooding and slugging? Flooding is a little liquid refrigerant reaching the compressor; slugging is a lot of liquid refrigerant reaching the compressor all at once.

How do you Unflood a compressor?

You could try to separate the refrigerant from the oil by heating the oil with a crankcase heater a few hours before starting the system, or by "jogging" the compressor. Jogging simply means that you start and quickly stop the compressor.

What are the causes of too much oil in a compressor?

Oil pressure trips can be caused by electrical problems. Any electrical problem that causes the motor windings inside the compressor to overheat can cause internal overloads in the compressor to open.

Does compressor oil mixing with refrigerant?

Oil and refrigerant vapor do not mix readily, and the oil can be properly circulated through the system only if gas velocities are high enough to sweep the oil along.

What causes liquid Floodback?

Floodback occurs when liquid refrigerant returns to the compressor during the running cycle. Often a service contractor may see a compressor that failed due to floodback, but because of the severity of the damage, he may misdiagnose the problem.

What happens when liquid gets into a compressor?

In reciprocating compressors, when a large volume of liquid appears inside the cylinder, and the piston cannot expel it through the discharge valve during the short duration when it is open, it leads to excessive pressure buildup inside the cylinder.

Why is my compressor oil foaming?

In general, foaming occurs when the oil-refrigerant mixture is exposed to a sudden pressure drop, as is the case in starting up a reciprocating compressor 1. The foaming oil may be sucked into a cylinder, which causes liquid compression and valve failure.

What is slug fluid?

The word slug normally refers to the heavier, slower moving fluid, but sometimes to the bubbles of lighter fluid. There are also small bubbles within the liquid, but many of these have coalesced to form the large bubbles until they span much of the pipe.

What can cause a compressor to ice up?

What Can Cause a Frozen Compressor? A clogged air filter that's limiting the amount of air that's moving over the cooling coil. Insufficient refrigerant or too much refrigerant that are causing icy buildup while destroying your compressor. A broken blower motor that's not funneling warm air over the cooling coil.

What is compressor flooded start?

Flooded Start is an off cycle problem. By definition, Flooded Start is caused when refrigerant vapor migrates to the compressor when the compressor is off. Floodback, the compressor is running; Flooded Start, the compres- sor is off. vapor wants to naturally mix with the oil used in refrigerant compressors.

What is the maximum discharge line temperature for Copeland compressors?

What is the discharge temperature limit of Copeland® compressors? Typically the maximum DLT is 225 ˚F. However, this temperature can vary depending on specific applications.

What causes high motor heat on an air cooled compressor?

What causes high motor heat on an air-cooled compressor? Inadequate airflow from the condenser fan. What causes high motor heat on a suction-cooled compressor? Low-mass flow of suction vapor to cool the compressor motor.

At what temperature will refrigerant oil break down?

The process by which the refrigerant and/or oil chemically breaks down can occur in a matter of seconds if there have been enough 18° tempera- ture increases. Mineral oil will start to decompose at approximately 350ºF (400ºF for POE oil). As temperatures increase above this threshold, the oil starts to polymerize.

What is the cause of oil foaming in compressor crankcase at the time of starting?

When the compressor is started, the sudden reduction in crankcase pressure causes foaming of the oil-refrigerant mixture. Depending on the amount of refrigerant in the solution, this foam can fill the compressor housing and be pulled into the compressor suction.

What causes refrigerant migration?

Refrigerant migration occurs as a result of a difference in vapor pressure between the oil in the crankcase of the compressor and the refrigerant vapor in another part of the system.

What is liquid migration?

A key principle underlying the concept of liquid migration is that migration forms an intrinsic part of wider social transformations within origin and destination countries in Europe.

Which refrigerants must be recovered before opening?

All CFCs and HCFCs must be recovered before opening a system for service or disposing of appliances. Cylinder & Appliance Disposal: Before disposing of any appliance containing a CFC or HCFC refrigerant, the refrigerant must be recovered.