View Full Version : heat Pump low and hight pressure switch

02-05-2017, 09:55 AM
hello all,

ı am a student wand I am studing on a heat pump design.
I have a sample design wiith ı dont understand points.

Could anyone help me ?

First as you can see fom attachment , there are 2 ballvales, one of them is for gas entry and I know that it should at side of low pressure. the second balvalve for what I dont know?

Secondly, again as you can see from attacment picture there is low and hight prssure swtich( I have marked with red cicrle.) these low and hign pressure switches are connecting tube which is gas entry side coming from balvallve. I would like to ask that how thsses pressure switches work exactly?

Thanks .

02-05-2017, 11:13 AM
Hello sioz1 and welcome to the forum.

In your first picture, it looks like both switches are attached to the same pipe therefore they won't be a high and low pressure switch.

Low pressure and high pressure switches are safety devices and are normally wired into the compressor control circuit. Both act to stop the compressor when they operate.

The low pressure switch is normally attached to the suction pipe on the inlet to the compressor.
The high pressure switch is normally attached to the discharge pipe on the outlet of the compressor.

In your second picture, the valves are 'Service Valves'. One on the low side of the system (suction gas) and one on the liquid line. This is where you can attach your service gauges to monitor system performance or add/remove the refrigerant.

02-05-2017, 01:12 PM
hank you Farnk, if I will have any question I am gonna write here.
Thanks again.