Ground fault protection for HVAC

[rajendrarohra1978]

Is there any standard which includes ground fault protection of HVAC system. The HVAC system includes blower motors, compressors etc. Is it enough to provide GFCI.

 

[dpc]

What country?

 

[waross]

What size.
A cord connected window unit or a directly wired unit?

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[rajendrarohra1978]

I am talking about Middle east. The Ground fault protection is for HVAC System for Substation, plant buildings etc. The HVAC system is designed with two compressor units with controls.

 

[ViCH]

Big industrial refrigeration compressors very likely to get short circuit, due to icing on motor body and on terminal box. It happens usualy if your freon low pressure drops, but not yet trip. If you dont want to loose whole distribution switchgear at that ground fault moment, better provide to HVAC panel one EFR, giving trip signal to MCCB.
In Malaysia HVAC units at plants always have EFR, set on 0.1-0.3 A (depends quantity of auxiluaries), 0.5 sec. I think, in this case You have to follow company's internal technical standarts, or plant electrcal design phylosophy.

Viktor
Electrical Technician II

 

[GroovyGuy]

Howdy rajendrarohra1978,
I have never encountered a specific requirement for GF protection on HVAC equipment.
Having said that, what is your distribution voltage and do you have a high-resistance grounded (HRG) neutral? [ie as opposed to a solidly grounded neutral or a ungrounded (ie delta) system].
Note: In my humble opinion, a system that utilises a HRG neutral is far superior type of distribution system. Here in Canada 99% of industrial LV power systems utilize a neutral ground resistor, commercial systems not so much.
Now having said that, there are manufacturers of GF indicating sensors available that can detect and alarm in the unlikely event of a GF on a system that contains a HRG neutral (ie Bender comes to mind as one such company).
Regards,
GG

"I have not failed. I've just found 10,000 ways that won't work." Thomas Alva Edison (1847-1931)

 

[stevenal]

2020 NEC (USA) 210.63(A) now has such a specific requirement.

 

[GroovyGuy]

Hi Steve,
Correct me if I have it wrong but NEC 210.63 requires you to install a 15A or 20A, 125V receptacle outlet within 25 ft of heating, air conditioning, and refrigeration equipment. The only exception to this rule is that you need not install GFCI protection for fixed electric snow melting or de-icing equipment receptacles that are not readily accessible and are supplied by a dedicated branch circuit in accordance with 426.28.
The above does not apply to 480Vac rated HVAC equipment, correct?
GG

"I have not failed. I've just found 10,000 ways that won't work." Thomas Alva Edison (1847-1931)

 

[stevenal]

Correct. An article I read on the changes seemed to indicate the HVAC gear needed the protection. Best to check the actual code.