Multiple small fans - industrial

[Electromatic]

A customer wants to install (30) 1HP/4.3A, 240V, 1Ø fans on each steel column of a long industrial facility. Particularly because of limited breaker spaces available, I'd like to group these onto a few 40 or 50A circuits. I reckon I'd then have to use something like a non-fused switch or air conditioning-style pull out disconnect at each fan. It seems kind of overkill for small fans. Is there a better way or something simple I'm missing?
BTW, they want all the fans controlled at one location, so I'm planning on using several contactors with a control switch or timer.

 

[Strathead]

You can just use snap switches in a 4S box. If the customer requests or requires a locking switch you can use a device like Garvin TOGLOK. Code doesn't require it though.

 

[Little Bill]

You would need to provide each fan with OCPD so you could install subpanel(s) and feed the fans from it. If the fans are cord and plug, you won't need disconnects.

 

[LarryFine]

Perhaps five groups of six fans, fed by five sub-panels spaced out, and a contactor for each feeder.

 

[Strathead]

You would need to provide each fan with OCPD so you could install subpanel(s) and feed the fans from it. If the fans are cord and plug, you won't need disconnects.

Why?

 

[Little Bill]

Why?

To protect the wiring to the fans.

 

[LarryFine]

Why?

Why to which part?

 

[Electromatic]

Oh yeah...OCPD. I'll have to put in several subpanels, then, and do cord-and-plug or 2P switches. (That or motor feeders with taps going to 30 separate fused discos!)

 

[Jraef]

You can just use snap switches in a 4S box. If the customer requests or requires a locking switch you can use a device like Garvin TOGLOK. Code doesn't require it though.

The problem with that will be terminating the 40 or 50A circuit conductors to the little snap switches.

The sub panel idea solves that too.

 

[Electromatic]

I wouldn't be allowed to put a 20A switch on a 50A circuit anyway, no?

 

[drcampbell]

Is 3Ø not an option?

 

[Engser18]

Oh yeah...OCPD. I'll have to put in several subpanels, then, and do cord-and-plug or 2P switches. (That or motor feeders with taps going to 30 separate fused discos!)

No you don't, one subpanel would do, run 20A circuit to 3 recepts (3 fans), total 10 - 2 poles CBs would do. you may need to up sized the wire due to voltage drops.

 

[augie47]

How about a manual motor controller such as an A-B 140M at each location with applicable feeder protection ?
Offers both S/C and overload protection.

 

[tom baker]

Are the motors thermally protected?

 

[Strathead]

To protect the wiring to the fans.

What I mean is, is there a code section that I am missing that requires a OCPD on each

The problem with that will be terminating the 40 or 50A circuit conductors to the little snap switches.

The sub panel idea solves that too.

I reviewed 404 before I posted. There is no prohibition to this. No different than putting a 15A switch on a 20A breaker, or a little 5A toggle switch on a piece of equipment. I am not aware of a code prohibition to this. I have found many times here, though, that I am missing something. I want to know if I am missing something.

 

[augie47]

A few things to consider:
Unless they are thermally protected, the fans need OL protection
The fans need short-circuit/ground fault protection per 430.52
Any "taps" off a larger feeder would need to meet the applicable 240.21 tap rule, normally meaning they need to terminate at an over-current device.

 

[Electromatic]

The fans do have built-in thermal protection, and they have already been ordered by the customer.
The squirrelly part about this installation is that the several 240V panels are scattered throughout the building, and each only has 2 or 3 breaker spaces left. (The service for the heavy equipment is actually 480V corner-grounded delta, and I think the 240V service is high-leg.)
It looks like the material cost for several subpanels vs. (30) 2-space breaker disconnects is actually about the same. I need to work out the copper and labor costs for the subpanel vs. motor feeder approach.

 

[Strathead]

A few things to consider:
Unless they are thermally protected, the fans need OL protection
The fans need short-circuit/ground fault protection per 430.52
Any "taps" off a larger feeder would need to meet the applicable 240.21 tap rule, normally meaning they need to terminate at an over-current device.

Ah, guess I didn't think that out very well. I was thinking of fractional horsepower fans, but even then I forgot that there is still a limit to the size of OCPD. My bad. Thank you.

 

[Electromatic]

It appears you are correct, though, @Strathead, that there is no requirement for a switch to have an OCPD to match its rating--they're just restricted by the load. I can't find anything in 404 or 210 that would prohibit putting a 15A toggle switch on a 50A circuit.

 

[HEYDOG]

It appears you are correct, though, @Strathead, that there is no requirement for a switch to have an OCPD to match its rating--they're just restricted by the load. I can't find anything in 404 or 210 that would prohibit putting a 15A toggle switch on a 50A circuit.

They will have to be rated for Horsepower!