Isolated ground in a fast food kitchen

Status
Not open for further replies.
D

Dominic Ramirez

Member
I need isolated ground, dedicated circuit receptacles in a fast food restaurant kitchen for the order processing equipment, such as monitors, ticket printers and order taking touch screens. All these circuits go back to a battery backed power dbl conversion conditioner. The GFCI rule in commercial kitchens is a problem or NEC's definition of a kitchen is too vague. Does anybody know of a legal way around this?
 
First, why do you need an isolated ground? The value of these things has been slowly diminishing, and very few applications would actually benefit from them.

But if you have a power conditioning device, is it being treated as a separately derived system? If so, you use receptacles with the isolated ground feature, run one EGC from the receptacle's ground pin connector back to the source, and run a second EGC from the receptacle outlet box back to the source, and you are there.
 
charlie b said:
First, why do you need an isolated ground? The value of these things has been slowly diminishing, and very few applications would actually benefit from them.
Click to expand...


I just did a bunch Isolated ground recepts for the P.O.S. at a bunch of Burger Kings last year, the reason why you need to do it, is because that is what the company that manufactures the equipment says it has to be on or it will void the warrenty. I dont really care whether it does anything or not, they pay me to run the circuits not decide whether they need it or not...
 
ultramegabob said:
I just did a bunch Isolated ground recepts for the P.O.S. at a bunch of Burger Kings last year, the reason why you need to do it, is because that is what the company that manufactures the equipment says it has to be on or it will void the warrenty. I dont really care whether it does anything or not, they pay me to run the circuits not decide whether they need it or not...
Click to expand...

IMO, that is really the only reason to do it that way. And a very good reason at that.
 
If you are using a double conversion UPS you are already way ahead of the game. The benefits of IG receptacles are as noted way overblown.

But if you insist set a panel with GFI CBs (assuming your UPS has an option for adding a panel) and IG away.
 
We've found that sometimes the ground fault breaker trips after plugging in 10 LCD monitors. The amp draw on these Monitors is .20 amps but they do have some current that leaks from neutral to ground, Maybe .001a but it adds up.
By the way I've had data corruption and lock-ups and then I go in there and find out they added a jumper at every Iso ground recptacle. We elimanate those and get a good iso ground for all POS and no more problems.

I would like NEC to add some detail to there descriptions of this situation because it seems each inspector interprets the NEC differantly.
 
If you have data corruption because someone grounded an IG to the EGC, you have more issues than just a bond jumper.
 
I agree and thats why I want an IG and stay away from thier dirty ground. It might be more of a ground loop problem, but I work for the POS manufacturer. So as long as the POS runs smoothly, the customers happy therefore I'm happy.
 
The only reason for an isolated ground is when the electronic devices are connected by multiple ground paths. Any 'computer' communication or printer cables that has a shield/ground wire may have a second ground path which might cause ground loops. Any device that uses only standard Cat 5 or Cat 6 interconnecting cables does not have any need for an isolated ground receptacle.

I feel connecting devices in a star grounding pattern 9dedicated grounding) is much more effective than isolated grounds. I do not know of an industrial installation that uses isolated grounds for its process equipment.
 
Last edited:
Is it me or is it that the people still specifying IG devices are lost in the last millennium?
 
Dominic Ramirez said:
I agree and thats why I want an IG and stay away from thier dirty ground. It might be more of a ground loop problem, but I work for the POS manufacturer. So as long as the POS runs smoothly, the customers happy therefore I'm happy.
Click to expand...


Yes but then you have a NEC violation and this (In My Opinion) must be corrected. If you have a double conversion UPS you are already isolated from other possible neutral ground issues.
 
Dominic Ramirez said:
I would like NEC to add some detail to there descriptions of this situation because it seems each inspector interprets the NEC differantly.
Click to expand...

The 08 NEC clarifies that IG can be bonded anywhere from the box back to the source.
Its a design issue don't expect more from the NEC.
 
Status
Not open for further replies.
Top