GFCI protection

Status
Not open for further replies.
M

Mr.Pash

Member
Location
Nevis
The code speaks specific to 15 and 20 amp 125volt GFCI protection for residential dwellings. Why is there nothing on 240volt and 30 amp GFCI protection or why is protection not required for the same areas at this voltage or amperage?
 
GFCI is meant to protect people. Since most equipment in a residential setting is the standard 120V 15 or 20 amp receptacle the code protects individual from faulty equipment, cords etc that they may plug into those devices. A home owner is not likely to use a 240v 30 amp or 20 amp receptacle.

BTW, welcome to the forum
 
Googling tells me that your location of Nevis is a standard 240V supply for common equipment, vice the US' 120V for most household things. Our National Electric Code may not be the best resource for you.
 
Mr.Pash said:
The code speaks specific to 15 and 20 amp 125volt GFCI protection for residential dwellings. Why is there nothing on 240volt and 30 amp GFCI protection or why is protection not required for the same areas at this voltage or amperage?
Click to expand...

Just because the code says that all 15 and 20A receptacles in certain areas must have GFCI protection, that does NOT mean that it is not required elsewhere. For example at pools, spas, ponds and water features, GFCI is required for all circuits, 120 or 240.
 
Mr.Pash said:
The code speaks specific to 15 and 20 amp 125volt GFCI protection for residential dwellings. Why is there nothing on 240volt and 30 amp GFCI protection or why is protection not required for the same areas at this voltage or amperage?
Click to expand...


Your location [Nevis] indicates you are in BVI [British Virgin Islands] . It would be much easier to come up with an answer if you were in USVI [United States Virgin Islands.] St. Croix, St. John.

USVI use the NEC while BVI use the British wiring standard.

They are almost two different worlds in terms of electrical construction practices.

Being an inspector. . . you probably use the "main ring" wiring systems?

I noticed when you alluded to the 30 Amp general use branch circuit.
In our US system. . . we use the radial style wiring system for general use [wall plug] circuits where the British call "sockets".

This main ring 30 Amp wiring technique will not work on GFI because of the "looping" circular arrangement of receptacles. . . where the extreme end of the homerun goes back to where it started in the load center. The British engineers think this system saves copper. They needed copper in their war effort during WWII.

They use this system in Malaysia a former British territory rich in British culture.

Our friend from Jamaica may be able to share some additional guidance.
 
myspark said:
This main ring 30 Amp wiring technique will not work on GFI because of the "looping" circular arrangement of receptacles. . . where the extreme end of the homerun goes back to where it started in the load center.
Click to expand...
They will work as long as you don't attempt to use the feed-through terminals and just pigtail to the line terminals.
 
myspark said:
Then you are defeating the purpose of the main ring.
Click to expand...
Unless I don't understand what the "main ring" is, I don't see the issue.

I envision, using USA convention, an NM "home run" cable leaving a panel, running from box to box, and then a second, redundant home run back to the panel, and landing on the same terminals.

A double-ended-fed circuit where a singe break anywhere in the loop would not remove power from any part of the circuit.

Any receptacle would have power coming in from both cables entering the box. A switch (and its unswitched neutral) would simply tap into the circuit, but the loop would not exist after the switch.

I envision a GFCI receptacle being fed the same way; as a tap on the loop. You could still use the two-wire capability of each terminal.
 
LarryFine said:
Unless I don't understand what the "main ring" is, I don't see the issue.

I envision, using USA convention, an NM "home run" cable leaving a panel, running from box to box, and then a second, redundant home run back to the panel, and landing on the same terminals.

A double-ended-fed circuit where a singe break anywhere in the loop would not remove power from any part of the circuit.

Any receptacle would have power coming in from both cables entering the box. A switch (and its unswitched neutral) would simply tap into the circuit, but the loop would not exist after the switch.

I envision a GFCI receptacle being fed the same way; as a tap on the loop. You could still use the two-wire capability of each terminal.
Click to expand...

Your scheme will work just like you would have a plug with a gfi protective feature. . .
not when using a circuit breaker at the load center.

Their plugs have fuses. . . and we don't have 30 amp GFCI circuit breakers.
I have 30 amp gfci plug in my motor home though. . .made in Zenchen, China.
Made special for RVs and no UL or CE listing. . .I'll lend to you in your field work. :D ;)
 
Correction

Correction

myspark said:
Your location [Nevis] indicates you are in BVI [British Virgin Islands] . It would be much easier to come up with an answer if you were in USVI [United States Virgin Islands.] St. Croix, St. John.

USVI use the NEC while BVI use the British wiring standard.

They are almost two different worlds in terms of electrical construction practices.

Being an inspector. . . you probably use the "main ring" wiring systems?

I noticed when you alluded to the 30 Amp general use branch circuit.
In our US system. . . we use the radial style wiring system for general use [wall plug] circuits where the British call "sockets".

This main ring 30 Amp wiring technique will not work on GFI because of the "looping" circular arrangement of receptacles. . . where the extreme end of the homerun goes back to where it started in the load center. The British engineers think this system saves copper. They needed copper in their war effort during WWII.

They use this system in Malaysia a former British territory rich in British culture.

Our friend from Jamaica may be able to share some additional guidance.
Click to expand...

Here in Nevis we once used the British 240v 2 wire system but we have since and for a while now been slowly converting over to the 3 wire 120/240v system used in the U.S as most appliances used on our island are U.S based appliances. There are still a few areas that still get the British 240v from the Utility but even then for domestic users each house would probably have a transformer. We also do use the radial style wiring here in Nevis. We do not have an adequate electrical code so we reference the NEC in most cases. I am now a new Trainee Electrical Inspector and I am trying to get as much knowledge as possible and quickly. I am also some what new to the NEC but have been in electrical for the most part of my life. With that said where does the NEC speak toward GFCI protection no matter the voltage or amp rating of the over current protection device?
 
Mr.Pash said:
The code speaks specific to 15 and 20 amp 125volt GFCI protection for residential dwellings. Why is there nothing on 240volt and 30 amp GFCI protection or why is protection not required for the same areas at this voltage or amperage?
Click to expand...
More places are probably coming where GFCI will be required. 2017 NEC had a significant change involving non dwelllings. Outside of ranges and clothes dryers, not too much else is cord and plug supplied at other than 15/20 amps/120 volts in typical dwelling, and GFCI is not a general requirement for non cord and plug connected equipment.
 
Status
Not open for further replies.
Top