I am replacing my old pool pump with a variable speed pump that calls for a dedicated 20 amp, 2 pole GFCI breaker, but I have not found an outdoor box with a 20 amp GFCI. The power from the mail panel is coming from a 30 amp breaker and I want to split this line with a GFCI dedicated for the pump. Home depot has a 50 amp GFCI panel for hot tubs... Can you please advise if I can use the 50 amp GFCI in place of the 20 amp GFCI?

Thanks for your help,

Two reasons you shouldn't try that. First, there is fire danger. The wiring will need to be sufficient to carry that much load. If your old circuit was rated at 20 amps then you need to stay with that, otherwise something other than the breaker will blow. Second, with a big breaker and small wiring, there's a chance that a long enough wire may have enough resistance to NOT trip the breaker should something short out. In that case, something grounded could become hot (live) and you can get a shock (dead).

Keep looking for what you need. There are electrical outlet stores that specialize in electrical equipment FAR AND ABOVE what you can get at a place like Lowe's, Home Depot, Ace and any other big box store out there.

Good luck.

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Thanks Tony. This is helpful and I will keep looking for the 20 amp GFCI breaker.

Best regards,

Ruben

After a careful read I thought it was very enlightening. I appreciate you taking the time to put this article together. Once again I find myself spending way too much time both reading and commenting. But so what, it was still worth it! =-=

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Originally Posted by Tonyr1084

Two reasons why you shouldn't try that. First, there is fire danger. The wiring will need to be sufficient to carry that much load. If your old circuit was rated at 20 amps then you need to stay with that, otherwise something other than the breaker will blow. Second, with a big breaker and small wiring, there's a chance that a long enough wire may have enough resistance to NOT trip the breaker should something short out. In that case, something grounded could become hot (live) and you can get a shock (dead).

Keep looking for what you need. There are electrical outlet stores that specialize in electrical equipment FAR AND ABOVE what you can get at a place like Lowe's, Home Depot, Ace and any other big box store out there.

Good luck.

")

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Hi,

You have three things to consider. Wire amperage rating is probably #10 wire, with a maximum fuse rating of only 30 amps, no code says it is unsafe to install a 20 amp breaker at the panel for #10 wire, you just can not go higher than 30 amps.

The 50 amp GFI really does not care if it is located on a 20 amp circuit breaker, or a 50 amp. It might not even care if it was on a 100 amp circuit, it will probably limit the amperage to only 50 amp maximum before tripping. It will still trip at a 0.006 amp imbalance between the conductors going into the load and back out, so it will still work as a GFI even if on a 20 amp main circuit breaker.

The new motor specifies that it must have a maximum over current protection of only 20 amps, so a new 20 amp circuit breaker in the panel will satisfy this need. The 50 amp GFI will provide GFI protection that is desired, and you will meet both of the requirements to make this new motor work safely.

So the 50 amp GFI will work safely if the overcurrent protection feeding it from the main panel is set to the motor's requirement of 20 amps max. You might find that a 20 amp GFI is much less expensive than a 50 amp, so you might save money by using the smaller GFI, but if there is no cost savings, then it is not a requirement to use a 20 amp, when overcurrent protection is not needed, the 50 amp rated equipment will be fine with the load that you have.

Fred.

Quote:

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Originally Posted by Ruben V

I am replacing my old pool pump with a variable speed pump that calls for a dedicated 20 amp, 2 pole GFCI breaker, but I have not found an outdoor box with a 20 amp GFCI. The power from the mail panel is coming from a 30 amp breaker and I want to split this line with a GFCI dedicated for the pump. Home depot has a 50 amp GFCI panel for hot tubs... Can you please advise if I can use the 50 amp GFCI in place of the 20 amp GFCI?

Thanks for your help,

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Very bad idea