LP/HP Connector Lines

[jwasir]

I've been told that flexible lines for LP/HP cut outs doesn't work good in cold wheather conditions.

The ID orifice (2 mm) clogs with oil and results vary with climatic conditions. Compressor sometimes goes into vacuum during pumpdown.

Do we need bigger dia. lines (1/4") copper pipe??

I've even seen small capillaries used with these controls (Danfoss).

Any views???

[nike123]

Since thru these lines there is no flow, only difference is in time to equalization off pressure changes at other side of tube. Since oil is not solidified, eventually pressure of system will be transmitted to control.
Bigger tube diameter means faster response at HP/LP control.

I have installed on some equipment longer and thinner lines as dampening device in order to avoid unnecessary triggering of high pressure switch caused by pressure bursts from compressor.

[K.R.Iyer]

I've been told that flexible lines for LP/HP cut outs doesn't work good in cold wheather conditions.

The ID orifice (2 mm) clogs with oil and results vary with climatic conditions. Compressor sometimes goes into vacuum during pumpdown.

Do we need bigger dia. lines (1/4") copper pipe??

I've even seen small capillaries used with these controls (Danfoss).

Any views???

Having flexi capillary connection to pressure cutouts and pressure gauges is a good method for longevity of cutouts and gauges. Whenever I located the HP cutout lines away from the warm condenser air ambient - in an isoltaed instrument panel, the high pressure rerigerant condenses in the flexi lines and naturally will have some oil also with it in noticeable amount. The presence of liquid and oil in the connecting tubes of cutouts does not affect the protection in any way.
The suction cutout pressure tapping on the suction tubing has to be from the top side of suction line. Is your LP cutout set at wrong value or faulty to let the compressor run in vacuum?

[jwasir]

The suction cutout pressure tapping on the suction tubing has to be from the top side of suction line. Is your LP cutout set at wrong value or faulty to let the compressor run in vacuum?

No LP cut out is fine. When we use the cutout with manifold gauges, it works fine but with these flexible lines, sometimes comp goes into vacuum.

The cut out seting is set @ 20 PSIG.

[Grizzly]

Try changing your gauge line for a temporary larger one.
And see what happens.
I like Nike am intrigued to know as to where the suction is connected.
It is unusual to oil log a suction line?
Grizzly