More GFCI's not cooperating.

[Pzlaket]

I am new to this board. I am a licensed contractor in good standing in CA.

I need some help. I just finished installing a 240/208/120 volt three phase 45kva transformer to supply support stations for a manufacturing plant with household current. The brake room has a dishwasher and garbage disposal on a dedicated circuit that is protected by a GFCI receptacle. Before writing this I read what many have wrote on this subject and true to form this device will open the circuit if the test button is depressed but not when a test plug is used. I roped the structure myself using MC cable [and anti-short bushings] so I know that all the grounding is done to code. It has all the signs of an EGC problem, but I have no idea how to correct this. The soil in the reagon is too alkaline to use a copper water line as a grounding electrode so I can only rely on a grounding rod for a grounding plan which is about fifty feet away from the receptacle.

Any ideas how to correct this problem?

Thanks in advance.

 

[Dennis Alwon]

Any ideas how to correct this problem?

Thanks in advance.

I would check and make sure you have a ground at the panel that is feeding the break room. It surely sounds like an open ground so I'm thinking there is no ground at the building itself. Make sure at the main service panel that the grounded conductor is bonded to the panel. I am not sure where to go from there.

 

[don_resqcapt19]

It looks like the system bonding jumper that must be installed at the transformer or the first OCPD is missing. Did you run a grounding electrode conductor to XO at the transformer?
Don

 

[brian john]

1. At the panel measaure voltage to neutral and ground for all phases, also measures neutral to ground voltage.
2. Do the same at various outlets.
3. As noted check all grounding.
4. Take ohm readings from neutral to ground.

 

[quogueelectric]

Multiple grounds

Multiple grounds

It sounds to me like you have more than one grounded point in the building. If you have an sds either pick up a new main bonding jumper at the first disconnect on the low voltage side and ground it to building steel. You could also bond the xo point on the xformer to building steel whichever is easier but NOT BOTH. Once the grounds are correct then make sure line amd load are correct and the gfci receptacle is grounded.

 

[Cavie]

Not trying to be a smart ass, but did you replace the gfi with one frome a different lot# I have seen whole boxes of devices defective.

 

[don_resqcapt19]

Cavie,
The test button on the GFCI trips it, so the GFCI is fine. The only reason for a GFCI not to trip with a plug in tester, when it works with the test button is an EGC that is missing or not connected to the grounded conductor at the source.
Don

 

[quogueelectric]

Well ???

Well ???

I am new to this board. I am a licensed contractor in good standing in CA.

I need some help. I just finished installing a 240/208/120 volt three phase 45kva transformer to supply support stations for a manufacturing plant with household current. The brake room has a dishwasher and garbage disposal on a dedicated circuit that is protected by a GFCI receptacle. Before writing this I read what many have wrote on this subject and true to form this device will open the circuit if the test button is depressed but not when a test plug is used. I roped the structure myself using MC cable [and anti-short bushings] so I know that all the grounding is done to code. It has all the signs of an EGC problem, but I have no idea how to correct this. The soil in the reagon is too alkaline to use a copper water line as a grounding electrode so I can only rely on a grounding rod for a grounding plan which is about fifty feet away from the receptacle.

Any ideas how to correct this problem?

Thanks in advance.

Well what was the solution??

 

[beanland]

Transformer Specifics

Transformer Specifics

Can you describe the 240/208/120V 3-phase tansformer? Is it 240V delta primary and 208/120V secondary? Is this a series of buck-boost transformers to convert 208Y/120 to 240V?

 

[brian john]

Post deleted because

 

[LarryFine]

Post deleted because

Good reas

 

[quogueelectric]

transformer

transformer

Can you describe the 240/208/120V 3-phase tansformer? Is it 240V delta primary and 208/120V secondary? Is this a series of buck-boost transformers to convert 208Y/120 to 240V?

My guess is that he installed a 208 delta primary to 240/120 wye secondary to turn commercial type power into a little closer to residential type voltages. However we havent heard anything for a while but I believe Don hit the nail on the head where this installation is somehow missing its sds bonding jumper and or ground. I am going with this theory anyway.

 

[sparky59]

are you using a test plug that also shows if there is other problems like an open ground or reverse polarity?

 

[beanland]

208V-240V 3-phase Converter

208V-240V 3-phase Converter

My guess is that he installed a 208 delta primary to 240/120 wye secondary to turn commercial type power into a little closer to residential type voltages. However we havent heard anything for a while but I believe Don hit the nail on the head where this installation is somehow missing its sds bonding jumper and or ground. I am going with this theory anyway.

What does this 208V delta to 240/120V wye 3-phase transformer look like? Got a manufacturer and model number? I can believe 208V single-phase to 240/120V single-phase. I can believe 208V delta to 240/120V 3-phase 4-wire delta. I can even believe 208V delta to 240/120V 4-wire delta.

 

[quogueelectric]

xformer

xformer

What does this 208V delta to 240/120V wye 3-phase transformer look like? Got a manufacturer and model number? I can believe 208V single-phase to 240/120V single-phase. I can believe 208V delta to 240/120V 3-phase 4-wire delta. I can even believe 208V delta to 240/120V 4-wire delta.

Delta/wye implies 3 phase primary/secondary

 

[Limey Pete]

Post deleted because

Because of what?