Commercial pool equipment room Load Calculations

[Sierrasparky]

Hello all, been some time.

I have been asked to check out a commercial pool equipment room for upgrades. I am concerned a service upgrade will be required.
To calculate the pump motor loads it is my understanding we take the nameplate rating and since they operate for over 3 hours continuously we add that.
Is it reasonable not use the continuous adder for the jet motors as they are on a timer for say 30 min. Yes it can be turned on multiple times.
Also these are Variable speed pumps so they only will see full HP at startup, Run speeds are generally less 3/4 rated full. It seems all these variable pumps are 3 HP lately.
Thanks

 

[Elect117]

I would be surprised if any of the motors run FLA continuously.

I would work through the HP or kW ratings, add them up. Multiply the largest by 125% and use 100% of the others. Then decide if you need to do any upgrading. See 430.24 for more info on how to do the calculation.

I would not assume any of the motors are "continuous".

 

[Sierrasparky]

Thanks
Well the circ pump runs 24hrs a day in winter.
When someone turns on the Jets that can last for many hours during big weekends and holidays.
I do know the circ pump runs at much lower speed than max. Maybe at the low speed which might be around 1 HP. 430.24 does not provide any solution for varying duty motors or ones operated at less than nameplate.
Using nameplate of a 3HP when the motor is programmed for 1 can make the service need upgrading big time.

 

[Elect117]

3HP, 230V motor is 17A. If that is enough to force you to need a service upgrade than maybe you need the service upgrade?

For service calcs, see 220.82(B)(4) if you are using the optional method.

 

[Sierrasparky]

3HP, 230V motor is 17A. If that is enough to force you to need a service upgrade than maybe you need the service upgrade?

For service calcs, see 220.82(B)(4) if you are using the optional method.

Thanks There are 7, plus electric heaters, plus sauna. I think the equipment room was designed around 1 1/2 HP motors. Spa and pools have been upgraded over the years. Now the place has been completely remodeled. By the way 220.82 (B) (4) is Residential. As my title says "Commercial "

 

[Elect117]

Thanks There are 7, plus electric heaters, plus sauna. I think the equipment room was designed around 1 1/2 HP motors. Spa and pools have been upgraded over the years. Now the place has been completely remodeled. By the way 220.82 (B) (4) is Residential. As my title says "Commercial "

My bad. I responded before I finished my coffee lol.

Maybe a VFD that feeds multiple motors might work to avoid the service upgrade? Then you are using the VFDs FLA and not the combined motors? I don't know how feasible that would be for pool equipment though.

But to be honest, if they are expanding, it could just be time for them to make that upgrade. So they can work in some additional stuff as well. Maybe add in some EV chargers in the parking lot or something.

 

[Sierrasparky]

My bad. I responded before I finished my coffee lol.

Maybe a VFD that feeds multiple motors might work to avoid the service upgrade? Then you are using the VFDs FLA and not the combined motors? I don't know how feasible that would be for pool equipment though.

But to be honest, if they are expanding, it could just be time for them to make that upgrade. So they can work in some additional stuff as well. Maybe add in some EV chargers in the parking lot or something.

Not being a EE I want to justify my recommendations. All these Pumps are self contained VFD's I think pentair. Trenching can be very expensive where I am. So I want to be sure. Yeah, this many pumps and all the assundry list of electrical loads make for a upgrade that they had not realized.
Thanks.

 

[Elect117]

How did you determine the existing loads? Did you try metering it for a extended period of time (Art. 220.87)? Sometimes calling the utility and asking for their demand metering data for a year suffices. That number should help in the calc. Most of the time the other standard and optional methods are higher than the actual demand data gotten from metering.