Differential Oil Pressure switch

Differential Oil Pressure switch

Serves to protect the compressor or  turn off the compressor when the oil pump pressure below the specified differential.

Working principle of differential oil pressure switch

When the compressor starts working, the mechanical lubricating pump driven by the crankshaft also starts pumping the lubricant. when starting to work the lubricant pump pressure has not been stable.

Differential Oil Pressure switch

Differential Oil Pressure switch

It takes under 120 seconds (depending on application, some use time delays of 45, 60, 90, and 120 seconds) so that the pressure of the lubricating pump becomes stable (the pump output pressure rises more than 9 psi from the suction pressure).

( Refrigrant pressure gauge)

If within the predetermined time the pump output pressure and suction pressure are still below 9 psi, the timer circuit in this Differential Oil Pressure will disconnect the electrical circuit to turn off the compressor.

Causes of pressure drop in the lubricant.

1. Damage to the mechanical parts of the lubricating pump.

2. Lack of lubricant in the compressor crankcase

3. Blockage of lubricant flow in the pump suction section or if the system uses an Oil Separator usually blockage of the lubricating flow controller needle in the Oil Separator.

Repair Steps

1. Mechanical damage can be done by overhauling the lubricating pump parts and replacing the damaged spare parts.

2. If the lubricant is lacking (can be seen in the oil level indicator) then we just need to add it so that the lubricant reaches the level in accordance with the provisions of its manufacture).

3. Blockage of the lubricant pump suction duct usually occurs in the filter in the crankcase compressor (clean the filter and replace the lubricant with a new one).

If there is a blockage in the Oil Separator, clean the Oil Separator, if the O / S of the hermetic compressor model is better replace it with a new one

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