semi hermetic checks

**steelman** · 05-11-2010, 09:30 PM

I have been doing HVAC for a few years now but I am new to these bigger comp. with unloaders and hot gas bypass. Is there a specific routine to do system checks? Even though cool outside should a adj to loaded and adj. for no bypass to check?

**ccservicefitter** · 05-12-2010, 10:21 AM

My suggestion is first go to a Copeland or excuse me Emerson (because they own everything) training seminar. They even do tear downs. Look on Emerson's web site and they show when and where they will be held in various parts of the country.

**steelman** · 05-12-2010, 11:52 AM

thanks for the response. I am actually signed up for a tear down class now. It's not by the 2 you named, but it's givin by the local supply house. I have alot of questions to ask. I hope they could help. Thanks again

**maxster** · 05-12-2010, 05:42 PM

if the unloaders are electric they will cycle according to air or water temperature setpoints when they get reached when ativated suction guage rises and discharge dros along with the amperages.the hot gas works off suction pressure to put a false load into the evaporsters usually fully opened with 55 lbs on the suction with r-22 as the gas.

**Octopus** · 05-12-2010, 07:07 PM

Copeland, Carlyle, dunham-bush and so on all have particulars, Oil level, that way the oil is distributed throughout the compressor, the way the valves/heads/plates function, Oil separators on low temps and other controls such as oil press switches are to also great to know, etc.... You can get great info from manufacturer web sights, classes and in the field.

**coolerinfrederick** · 05-12-2010, 10:02 PM

chrishvacman, nothing like good ol hands on experince though, just don't puch in one contactor on part winding start comp. and read read read

**steelman** · 05-13-2010, 10:24 PM

Thanks for responding back. I did go to a Carlyle class, tear down. Learned alot. I think you guys are right. need to get my hands on while learning. Boy I have a long way to go.