Can a 20a gfi be used on a 30a circuit w/#10 wire w/a 20a load?

Status
Not open for further replies.
V

Voltron4160

New member
Location
Fl
Hi guys I'm new to this forum. Just asking this question because I can't find any 30a 120v gfci receptacles at Home Depot. What would happen if I used a 20a gfci for the time being until I order a 30a receptacle. This is a dedicated circuit that will have a load of 20amps at 120v.
Thanks in advance, any suggestions would greatly help.
 
I doubt that you will find any.
Since it is a dedicated circuit, why not use a GFCI breaker?
Or is it an old panel with no GFCI available?
 
I'm with GD on this one, may be waiting a long time before any one comes out with a 30 amp GFCI receptacle.

They do make 30 amp GFCI breakers though.
 
Voltron4160 said:
Hi guys I'm new to this forum. Just asking this question because I can't find any 30a 120v gfci receptacles at Home Depot. What would happen if I used a 20a gfci for the time being until I order a 30a receptacle. This is a dedicated circuit that will have a load of 20amps at 120v.
Thanks in advance, any suggestions would greatly help.
Click to expand...

Welcome to the forum.

A 30A plug will not fit a 20A receptacle. You cannot use a 20A receptacle on a 30A circuit; 210.21(B)(3).

You can use a 30A single pole GFCI breaker with a standard 30A receptacle. You may put a 20A load on a 20A receptacle if it's an individual branch circuit (one outlet) and the load isn't continuous (>3hrs). What kind of load do you have that draws 20A on a 120V line? The few cord and plug appliances I've seen that draw that kind of current are either non-continuous, or on 240V.

Are you sure it draws 20A, or is that the recommended circuit ampacity (MCA)?

eta: if the panel is too old for a GFCI breaker, you could install a small subpanel from it and GFCI from there.
 
Last edited:
kwired said:
I'm with GD on this one, may be waiting a long time before any one comes out with a 30 amp GFCI receptacle.

They do make 30 amp GFCI breakers though.
Click to expand...
I would expect that with the changes to 210.8(B) for the 2017 code, that a 30 amp GFCI receptacle will be available in the not too distant future. I can't imagine the wiring device manufacturers leaving that market to the breaker manufacturers.
 
The definition of a GFCI wiring device limits it to 20A. GFCI breakers are different, so that is your only option if you need a 30A GFCI protected receptacle.

So if the load is only 20A, why do you need a 30A receptacle? I ask because in general if the equipment came with a 30A cord cap, it would be there BECAUSE the mfr knew that 20A was insufficient. For example if the load current is EXACTLY 20A continuous, the conductors and thereby the OCPD need to be 25A minimum and since there is no 25A receptacle, that's how you end up with a 30A.
 
Jraef said:
The definition of a GFCI wiring device limits it to 20A.
Click to expand...

I am not sure I understand this statement.

Art.100

Ground-Fault Circuit Interrupter (GFCI). A device intended
for the protection of personnel that functions to deenergize
a circuit or portion thereof within an established
period of time when a current to ground exceeds the values
established for a Class A device.
Click to expand...
 
jumper said:
I am not sure I understand this statement.

Art.100
Click to expand...
But the UL 943 definition of a Class A GFCI wiring device is limited to 15 and 20A. So although technically the N EC would allow it, UL rules prevent it from being listed, so without being able to list it, nobody is going to make it.
 
Expressing ourselves in absolute terms causes absolute embarrassment.

leviton_high_current_smartlock_gfci-back_and_side_wired_8895.jpg
SmartLock High-Current GFCI
Adds Ground-Fault Protection to Heavy Equipment
Cat. No. 8895 (up to 80 Amps)
• UL Recognized Component #E-48380

See attached PDF
8895-80.pdf
 

Attachments

  • 8895-80.pdf
    88.2 KB · Views: 0
Last edited:
ramsy said:
Expressing ourselves in absolute terms causes absolute embarrassment.

View attachment 18337
SmartLock High-Current GFCI
dds Ground-Fault Protection to Heavy Equipment
Cat. No. 8895 (up to 80 Amps)
• UL Recognized Component #E-48380

See attached PDF
8895-80.pdf
Click to expand...
Take note that this is NOT listed as a Class A GFCI... If it was, they would have said so. It is not actually UL listed at all, it is a UL Recognized Component, meaning it can be USED in another system as a comoponent for something that will then be itself listed. So it cannot be used by a contractor in the field as a a drop-in device.

The devil is in the details...
 
ramsy said:
Expressing ourselves in absolute terms causes absolute embarrassment.

View attachment 18337
SmartLock High-Current GFCI
Adds Ground-Fault Protection to Heavy Equipment
Cat. No. 8895 (up to 80 Amps)
• UL Recognized Component #E-48380

See attached PDF
8895-80.pdf
Click to expand...

If I am reading the specs correctly, that device is limited to being supplied with power by a 20A 125V circuit.

The 80A interrupting rating is the associated control relay(separate).
 
Jraef said:
Take note that this is NOT listed as a Class A GFCI... If it was, they would have said so. It is not actually UL listed at all, it is a UL Recognized Component, meaning it can be USED in another system as a comoponent for something that will then be itself listed. So it cannot be used by a contractor in the field as a a drop-in device.

The devil is in the details...
Click to expand...

The only time I have seen those things used was in listed pump control panels.
 
jumper said:
If I am reading the specs correctly, that device is limited to being supplied with power by a 20A 125V circuit.
Click to expand...

Its even more restricted than that. The GFCI device has LOAD side terminals rated at 0.6 Amps max, at 20 to 120 Volts. The GFCI device can only drive relays.
 
Jraef said:
Take note that this is NOT listed as a Class A GFCI... If it was, they would have said so. It is not actually UL listed at all, it is a UL Recognized Component, meaning it can be USED in another system as a comoponent for something that will then be itself listed. So it cannot be used by a contractor in the field as a a drop-in device.

The devil is in the details...
Click to expand...

1) It says Class A, on the device yolk - Blow up bottom right diagram--

2) Does "Not listed" mean can't be AHJ approved in the field?

3) If 2-pole GFCI breaker won't fit in fuse box, HC-GFCI in deep 2G box / 1G P-Ring with this relay mounted to back of box

4) If no 15A/20A convenience circuit is available to control the 20A GFCI, add a fuse block
 
Status
Not open for further replies.
Top