Hot tub disconnect

[nizak]

Customer is having a new hot tub installed. His existing disconnect is a 50 amp GFCI type breaker.The tub specs call for a 40 amp.

Would there be anything wrong with just putting a 2 pole 40 amp breaker in the load center feeding the disco?

Thanks

 

[Little Bill]

Customer is having a new hot tub installed. His existing disconnect is a 50 amp GFCI type breaker.The tub specs call for a 40 amp.

Would there be anything wrong with just putting a 2 pole 40 amp breaker in the load center feeding the disco?

Thanks

I've been through this before. Some mfg don't figure in the 125% for the motor. so you actually need the 50A breaker (GFCI) .
40A x 125% = 50A

 

[kwired]

I've been through this before. Some mfg don't figure in the 125% for the motor. so you actually need the 50A breaker (GFCI) .
40A x 125% = 50A

Never seen a hot tub with a 40 amp motor in it.

Leaves no room in supply circuit for a heater either, but then again with that big of a motor, friction in the pump and piping probably does the heating

 

[FionaZuppa]

I've been through this before. Some mfg don't figure in the 125% for the motor. so you actually need the 50A breaker (GFCI) .
40A x 125% = 50A

So, NEC says to follow manufacturer's install instructions. You override this how? With many new motor setups using electronic step-up turn on sequences to reduce inrush currents, I wonder if this 125% rule needs some fixing?

But "The tub specs call for a 40 amp" is vague. Spec for what? ckt spec, or is that a OCPD spec?

And just to boot, a lot of device spec I see on paper does not get realized in real use. 50A spec'd tub, I never see anything near that for inrush and/or with heaters on. They seem to over spec the feed by good amount of headroom, and then you thrown in the 125% rule, now you way over.

 

[Little Bill]

So, NEC says to follow manufacturer's install instructions. You override this how? With many new motor setups using electronic step-up turn on sequences to reduce inrush currents, I wonder if this 125% rule needs some fixing?

But "The tub specs call for a 40 amp" is vague. Spec for what? ckt spec, or is that a OCPD spec?

And just to boot, a lot of device spec I see on paper does not get realized in real use. 50A spec'd tub, I never see anything near that for inrush and/or with heaters on. They seem to over spec the feed by good amount of headroom, and then you thrown in the 125% rule, now you way over.

Not overriding the mfg. Many of them just put the running amps or output current on their sheets. They don't say "must be XXA circuit. You have to take into account the requirements for motors yourself. I discovered this when I was installing a tub and all I saw was it ran on 48A. After some digging, I found instructions that said to use a 60A breaker. So do the math, 48A x 125% = 60A, same with 40A, 40A x 125% = 50A. That's why most will say "to be installed by a qualified electrician". So we are supposed to know how to size such circuits.

 

[FionaZuppa]

Not overriding the mfg. Many of them just put the running amps or output current on their sheets. They don't say "must be XXA circuit. You have to take into account the requirements for motors yourself. I discovered this when I was installing a tub and all I saw was it ran on 48A. After some digging, I found instructions that said to use a 60A breaker. So do the math, 48A x 125% = 60A, same with 40A, 40A x 125% = 50A. That's why most will say "to be installed by a qualified electrician". So we are supposed to know how to size such circuits.

If their spec/install sheet calls out a 40A ocpd I dont think you apply the 125% rule. If the spec sheet is BC amps then apply 125% rule for ocpd.

Certainly one is scratching head if spec sheet says "48A ocpd".

 

[Greg1707]

40 amp 30 amp draw

40 amp 30 amp draw

I just installed a Jacuzzi. The instruction stated

"240 volt 40 amp breaker. 30 amp load."

There was no mention of disconnect etc. in instructions.
I installed a 50 amp GFCI spa disconnect from HD. Installed 40 amp breaker in panel.

 

[Little Bill]

I just installed a Jacuzzi. The instruction stated

"240 volt 40 amp breaker. 30 amp load."

There was no mention of disconnect etc. in instructions.
I installed a 50 amp GFCI spa disconnect from HD. Installed 40 amp breaker in panel.

30 x 125% = 37.5A next size up 40A
I rest my case!

 

[Knuckle Dragger]

Nothing wrong with doing what the manufacturer recommends.
I would check the FLA and RLA. If you have any questions after that I would contact the manufacturer.

 

[kwired]

I just installed a Jacuzzi. The instruction stated

"240 volt 40 amp breaker. 30 amp load."

There was no mention of disconnect etc. in instructions.
I installed a 50 amp GFCI spa disconnect from HD. Installed 40 amp breaker in panel.

That is what I would likely do. You usually can get those spa disconnect packages (with a 50 amp GFCI breaker in them) for less than you can purchase the 50 amp GFCI alone.