Booster pump breaker sizing in panel

[hhsting]

Attached sketch i have panelboard breaker feeding control panel which feed three booster pumps each 15HP 208V three phase and manufacturer says each has FLA of 46.2A.

The control panel internal manufacturer provided 80A fuse for each booster pump. Designer says the fuses are for overload protection.

I am not sure if I am using the correct code section for sizing the feeder breaker supplying the control panel which is NEC 2017 Section 409.21(C) or not. According to that, if there is no short circuit and ground fault protection in control panel then to use 430.52 and 430.53 as applicable. Otherwise if short circuit and ground fault protection is provided then use 409.21(C). The internal 80A fuse according to designer is for overload protection

So my question is would one use 409.21(C) or 430.52 and 430.53? Does fuse provide short circuit and ground fault protection or not if it provides overload protection?

 

[don_resqcapt19]

Yes a fuse will always provide short circuit and ground fault protection. See Table 430.52.

However I doubt that 80 amp fuses will provide overload protection for a motor with a full load current of 46.2 amps. 430.32.

 

[Eddie702]

These pumps must have a motor starter or contactor or something. How are they being started and stopped??

Also, you have to size the conductors and breaker using the amp draw in the code book

 

[hhsting]

These pumps must have a motor starter or contactor or something. How are they being started and stopped??

Also, you have to size the conductors and breaker using the amp draw in the code book

I dont have the exact details of internal to control panel except the internal manufacturer fuse size. Amps drawn are coming from manufacturer so says designer. I see if he provided anything

These booster pumps in high rise residential building if that makes difference.

 

[hhsting]

These pumps must have a motor starter or contactor or something. How are they being started and stopped??

Also, you have to size the conductors and breaker using the amp draw in the code book

I have the following posted on plans:

Booster pump is pro-22TJ15xxx-6h-xx-swf55-3 which is triplex booster system utilizing (3) 15HP pumps and rated at 208V/3PH service, will use 80A fuse for the internal motor protection.

More specifically they use Bussman Model LPJ-80SP fuses in control panel. See below for data sheet for this fuse

 

[don_resqcapt19]

I have the following posted on plans:

Booster pump is pro-22TJ15xxx-6h-xx-swf55-3 which is triplex booster system utilizing (3) 15HP pumps and rated at 208V/3PH service, will use 80A fuse for the internal motor protection.

More specifically they use Bussman Model LPJ-80SP fuses in control panel. See below for data sheet for this fuse

an 80 amp fuse for overload protection will get a violation notice from me

 

[Jraef]

According to their catalog, that pump panel has VFDs on each motor, so the fuses are just the SCPD for the VFDs, probably because that's what the VFD is listed with. The VFD will be protecting the motor.

Depending on the purpose of the triplex panel, it may only alternate two p[umps and never run all three at the same time, but if you don't know that for sure, you would size the feeder conductors for the 3 FLAs combined plus an added 25% of one of them and any other loads like a control transformer etc., (430.24) or stated another way 125% of the first one, plus the other loads added to it. So 46.2 x 1.25 = 57.72 + 46.2 + 46.2 = 150.15, then because it has control power too, I would give it at least 175A rated feeder conductors. Then per 430.62, you size the feeder protection based on that. If it were me though, I would go for 200A conductors and feeder breaker.

 

[augie47]

Would Art 409 not come into play in which case one would follow nameplate data.
With a NRTL listed control cabinet I would not question any internal components but simply make sure the supply matches the nameplate, normally an inspectors task.

 

[Jraef]

Note by the way, the 10kA SCCR rating. That is not all that high for anything industrial, you might want to check out what your available fault current is at the site and insist that they give you a panel with an SCCR at least that high.

 

[Jraef]

Would Art 409 not come into play in which case one would follow nameplate data.
With a NRTL listed control cabinet I would not question any internal components but simply make sure the supply matches the nameplate, normally an inspectors task.

Yes, the supply is required to match the panel nameplate IF IT HAS ONE. I would expect that they would tell you that when you buy the panel, but that's just me...

The model number for the panel by the way appears to have a "200A" in the middle of it, so that might indicate it has a 200A main. The description says it has a "single main power feed".

 

[tom baker]

With a NRTL listed control cabinet I would not question any internal components but simply make sure the supply matches the nameplate, normally an inspectors task.

Agreed, and that is what the NEC states.