On parallel compressor installations or oil level does not equalize. or remain at a constant level in all constant level in all compressor

Oil equalization line not level, preventing gas equalizations. (Note: oil equalization lines cannot be used with two stage compressors, a float system must be used.) - Level oil equalization line

Pressure equalization check valve in the motor rotor lock bolt may have been left in one or all compressors.(Note: check valve not required with float system.) - Remove suction service valve and look for check valve in motor rotor bolt at the end of the crank shaft. Check valve is required on all compressors in parallel systems using the oil equalization line connected at the sight glass location.

Excessive blow by into crankcase worn rings valves on blown gaskets. - Replace gasket, valve plate (reeds) or other damaged running parts.

Improper suction line sizing - Resize lines.

Oil reservoir check valve bad or wrong pressure. - Replace check valve;20 psi check valve required.

With float system: Oil is not equalized in sight glass

a. check floats .replace defective floats.

b. check for proper selection and setting site glass connection.

c. if floats have equalization line, the line between the floats may have to be removed. Contact dealers.