50amp GFCI Spa panel safe at well below 50amps?

Planning my electric build and just curious if there i any safety issue using the 50amp GFCI breaker from the spa panel on something i may only be pulling ~25 or 30 amps out of.

I imagine most the time i'll be using 1 element at a time, but would like the expandability in the future but don't want to incur the risk of not tripping the GFCI if something were to happen.

There is no problem with that, provided your feeder is rated for at least 50A. The GFCI will trip on ground fault current on the order of milliamps.

+1 gfci are designed to save your life and less than 1/2 amp can kill

No safety issues at all.

In the USA a GFI meant to protect lives will trip when it senses a mismatch of only 5 mA (0.005 amps) of current between that flowing in vs that flowing out (so to speak).


Kal

Fantastic! Thanks for all the help.

I know this is an old thread but I am getting a 30amp BCS 460 panel from Ebrewsupply, i have 30 amp service to the brew room. So a 50 amp panel will not offer GFCI protection? I am having a hard time finding a 30 amp panel. May be cheaper to put a GFCI breaker in the box?

Thanks for any input

The spa panel *will* offer GFCI protection. It will not offer overcurrent protection -- that should be covered by the breaker at the main service panel.

Yes, the spa panel will indeed offer overcurrent protection. However, it should never trip if it's being used on a 30-amp circuit, because the 30-amp breaker would trip first.

danb35 said:

Yes, the spa panel will indeed offer overcurrent protection.

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Assuming he matched his wiring sizes to the 30a breaker in the main, the spa panel will NOT offer overcurrent protection. The wiring could cook long before the 50a breaker trips. The 30A breaker at the main panel provides the overcurrent protection, the 50a GFCI would only provide GFCI protection.

Most spa panels do not offer overcurrent protection anyway...it seems to be a bit of a misnomer to call them 'breakers', the number on the box is only a current rating for the disconnect. The GFCI disconnects in them will work with any load UP TO what they are rated, and still operate as desired. They will still trip with a 2A load if there is a ground fault.

Ok guys thanks for the input. Sounds like I will be safe to use a 50 amp spa panel along with the breaker in the box? The main breaker will offer the Overload protection and the spa panel the gfci protection.

If you main panel has a 30amp breaker then you are OK with 10GA wiring.

Otherwise make sure that your power cord and other wiring from the spa panel to the brewery control panel are rated for 50 amps. The breaker is designed to protect the wiring. You don't want the wiring to act as a fuse (by using 30amp/10GA wiring and a 50 amp breaker)

I also need some clarification regarding the spa panel and wire size.

I have a 50A spa panel feeding my control panel which will use one 5500W element at a time with one pump. I currently have a 10 gauge main power cord that I was going to use, but I am thinking now that since 50A is behind it, I should be using 6 gauge.

I've got a receptacle for my main power coming in that is rated for 30A. Should I get one that is rated for 50 instead?

Do I need a 30A breaker inside my main panel?

As stated earlier, if you put a 30a breaker in the panel, and use the 50a spa panel for GFCI purposed, then your wiring and receptacles need to be rated for 30a. If you are only going to run one 5500w element at a time, that would be a good approach.

jeffmeh said:

As stated earlier, if you put a 30a breaker in the panel, and use the 50a spa panel for GFCI purposed, then your wiring and receptacles need to be rated for 30a. If you are only going to run one 5500w element at a time, that would be a good approach.

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Just to make sure I have this right:

50A GFCI -> 30A Breaker (Both in the spa panel)

10 gauge wire to main receptacle on brewery control panel and 30A service throughout the brewery control panel.

I couldn't feed the main brewery control panel from the 50A GFCI THEN into a 30A breaker right?
--edit: If I did go this route, I'd do 6 gauge wire to a 50A receptacle on the brewery control panel, then into a 30A breaker.

A 50A GFCI in the spa panel doesn't mean you are running 50A service. The breaker at the main panel determines the service. What are you feeding the spa panel with at the main panel?

Broham1 said:

A 50A GFCI in the spa panel doesn't mean you are running 50A service. The breaker at the main panel determines the service. What are you feeding the spa panel with at the main panel?

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60 Amps

Maltose said:

Just to make sure I have this right:

50A GFCI -> 30A Breaker (Both in the spa panel)

10 gauge wire to main receptacle on brewery control panel and 30A service throughout the brewery control panel.

I couldn't feed the main brewery control panel from the 50A GFCI THEN into a 30A breaker right?
--edit: If I did go this route, I'd do 6 gauge wire to a 50A receptacle on the brewery control panel, then into a 30A breaker.

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What I was describing was a 30a breaker in your main house panel, with 10awg going to the 50a spa panel GFCI, and then to the control panel. Your 30a breaker is providing overcurrent protection and the 50a breaker is providing GFCI. You have a 30a feed.

If you wanted to run 50a to your control panel you would put a 50a breaker in the main house panel, with 6awg going to the 50a spa panel GFCI, and then to the control panel. You could then use breakers or fuses in the control panel if you wanted to be able to downsize the wiring, e.g. running 10awg to each element off of a 30a breaker.

Maltose said:

Just to make sure I have this right:

50A GFCI -> 30A Breaker (Both in the spa panel)

...

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This will not work. The Spa Panel does have a 50A GFCI breaker in it. It also had room within the Spa Panel for an additional 30A breaker.

However: The GFCI breaker and the 30A breaker would be fed through the same input wiring going into the Spa Panel. In other words the GFCI does not and will not protect the added breaker.

Just check out your power feed to your brewery area. What size breaker in your mains panel is being used to protect the circuit and outlet that you intend to use? 30A? If so the circuit and power feeding your brew area is a 30A circuit.

At that point, the Spa Panel will only be providing GFCI protection.

I guess my other option is to drop money on another GFCI breaker to put in my new spa panel. The panel is a Cutler-Hammer BR50SPA. I'm assuming I can get a 30 amp BR-style breaker and swap it?

Maltose said:

60 Amps

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Then you can do what I described for the 50a breaker and 6awg wire in the last post.

Also, note that with the 50a GFCI spa panel you will need to design your control panel to live within 50a. You could go with a 60a GFCI spa panel if you needed the extra 10a of headroom.

Maltose, you have a 60a main breaker, and a 50a GFCI spa panel. What do you want your brewery panel to support (element size, how many at once, PIDs, pumps, etc.)?

jeffmeh said:

Then you can do what I described for the 50a breaker and 6awg wire in the last post.

Also, note that with the 50a GFCI spa panel you will need to design your control panel to live within 50a. You could go with a 60a GFCI spa panel if you needed the extra 10a of headroom.

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Yeah I've basically got all the parts for a 30A panel so I'd like to feed it with only 30

Maltose said:

Yeah I've basically got all the parts for a 30A panel so I'd like to feed it with only 30

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You may want to check out this thread. https://www.homebrewtalk.com/f170/has-anyone-added-30a-breaker-50a-gfi-spa-panel-397746/

Let's say I keep the 50A coming in....where would I be running my wire after it comes into the panel at 50A? I'd probably hard wire 6/3 with ground into the panel that would go into a first circuit breaker.

Thanks for everyone's help so far.

I did something similar (ish) - 50a (6ga) from panel to spa panel to control panel. 6ga hits contactor, goes from there to 4 distribution blocks (Hot A, Hot B, Neutral, and Ground). 10ga from the Hot A / B a very short distance to 2 internally mounted DIN 25a breakers and 1 15a breaker. From those, appropriately sized wire to individual components. You could do the same and survive, or put a 30a breaker in the Spa Panel like jeffmeh shows in the link above.

BadNewsBrewery said:

I did something similar (ish) - 50a (6ga) from panel to spa panel to control panel. 6ga hits contactor, goes from there to 4 distribution blocks (Hot A, Hot B, Neutral, and Ground). 10ga from the Hot A / B a very short distance to 2 internally mounted DIN 25a breakers and 1 15a breaker. From those, appropriately sized wire to individual components. You could do the same and survive, or put a 30a breaker in the Spa Panel like jeffmeh shows in the link above.

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That certainly works. I would expect the 30a breaker with all 10awg would be less expensive than the two 25a breakers with 6awg, particularly if there is a long run.

jeffmeh said:

That certainly works. I would expect the 30a breaker with all 10awg would be less expensive than the two 25a breakers with 6awg, particularly if there is a long run.

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Agreed. I did mine because I want to run both elements at the same time so I needed the full 50a capacity. If OP only wants 30a, there's no reason to run 6ga. The easiest (cheapest?) thing to do would be to replace the 60a panel in the main breaker, run 10ga to the spa panel and then to the control panel. Even in a relatively short run it'll probably pay for the cost of the 30a breaker in savings on wire, not to mention the smaller size is way easier to work with!