PDA

View Full Version : Use Of Gfi Outlets In Refrig. Circuits



FEISTY
24-06-2008, 08:57 PM
As always...hope all of you are doing well and staying healthy !! My question is quite simple but the answer may not be. What is the guideline for using GFI circuit outlets on refrigeration equipment. Here in Chicago, code is GFI protected circuit if equipment is within 6 feet of a " water source ". I have found that a compressor, whether 1/4..1/3..or 1/2 hp. at 120v. will trip these outlets at the slightest ramping of start-up draw. The older the unit and the tighter the motor, the quicker the trip. How does " the field " tech address this? I insist the cust. remove the GFI or pay the reset service call charge. Am I right or do I need to look at this another way?? Thanks for any opinion. Feisty:cool:

nike123
24-06-2008, 10:25 PM
If you using 50mA GFI device, then faulty equipment should have insulation resistance lower than 2400 Ohm. That is unlikely with equipment who is in good working order. That leaves you with bad wiring (insulation) of protected circuit.
Check that with new cable (extension cord or freely layed cable from GFI device to equipment).

Brian_UK
24-06-2008, 10:32 PM
Just a note for the UK members who may not understand GFI - we call them RCD. ;)

Grizzly
25-06-2008, 05:44 AM
Just a note for the UK members who may not understand GFI - we call them RCD. ;)

Thanks yet again Brian.
As it had me confused!!!
Grizzlyhttp://www.refrigeration-engineer.com/forums/images/icons/icon14.gif

FEISTY
25-06-2008, 12:24 PM
I don't seem to be getting the info I was after. Does this " problem " exist with your equip. and power supply or is it just here in the states? All of my jobsites have the same results. Double amp draw on start-up for a split second is enough to trip the outlets. My only solution is to have a " sparky " install protection on the main panel across all breakers. That seems to have a forgiving effect and the units don't trip on start-up. FEISTY

Blackbird
25-06-2008, 01:12 PM
Start up current will not trip an RCD...Only an imbalance of current between active & neutral conductors. Unless you've got an RCD/CB combo in which case they incorporate a CB to protect you're wiring. A motor starting will generally not trip a C curve CB but if it does change it to a D curve.

I would be getting my megger out and checking the equipment.

FEISTY
25-06-2008, 11:31 PM
Thanks for the " input ". I have several locations that have had this condition occur and in all cases removing the GFI outlet solved the problem. Also customers using extension power strips for multiple outlet access have the same problem. I talked to tech. advisor at 2 diff. compressor mfg. and got the " off the record " answer of yes it happens and no we won't admit it. They advise the shortest and most direct power supply is always factory recommended. City inspectors do not demand the GFI if they know compressor equip. in line. SO..... I guess do what works as long as it is a 100% safe and " legal " situation. Again thanks for the tech talk. Hope to return the favor !! FEISTY.