Wiring pool pumps off "hot tub feeder "

[sparkync]

When figuring the feeder size to pool pumps and equipment, I know that I take the largest motor at 125% and then add the FLA of the other motors, but do I take the 115v FLA or the 240v FLA if the motor is dual voltage? I thought I read somewhere in the code that you have to figure it ( the feeder, not branch circuit ) for the higher amperage even though it's not going to be used at the time. A feeder has already been pulled for a hot tub, and it was supposed to be big enough to feed the pool, but I don't think it is at this point. I have to do some more checking. It looks like they have pulled #6 wire (or # 4 at the most), to a 4 circuit wp panel. They have a 60amp. GFI breaker feeding the hot tub. I will have to look and see what the hot tub actually calls for, and the size of motor it has. I'm guessing it will be the largest motor of the group and that I will have to figure it at 125% then the others at 100%FLA, but whether I take it at 115v or 240v is my question. Thanks for the help...Steve
Problem here is that if I have to pull another feeder, I will be coming out of the panel in their house, under a 10 or 12 ft. asphalt driveway then about 100ft. to the pool panel

 

[RUWired]

Steve, You will have to take 125% of the pool pump (table 430.248 if 120 volt) and 100% of the nameplate rating of the hot tub for the feeder to the 4-circuit panel.
Rick

 

[Bob NH]

You need to look at the amps on the motor nameplate.

I installed one last summer that the vendor had put a prominent 6 HP sticker on the motor, but it was only drawing 12 Amps per the nameplate that was behind the motor and hard to see.

The sticker was just to make the customer feel good about the great deal he got when he bought the hot tub and had nothing to do with the electrical characteristics of the motor.

If it is dual voltage, you should connect it for 240 Volts and use the 240 Volt current rating, assuming the controller is capable of delivering 240 Volts. They usually don't shift voltage while running, unless they have some special 2-speed motor that uses a different voltage.

The biggest real load is usually the heater.

 

[Bea]

If it is dual voltage, you should connect it for 240 Volts and use the 240 Volt current rating, assuming the controller is capable of delivering 240 Volts. They usually don't shift voltage while running, unless they have some special 2-speed motor that uses a different voltage.

I agree use table 430.248 based on the voltage the motor is going to be operated at

 

[sparkync]

Rick, I seem to be missing 2 things here. First if the hot tub motor is the biggest motor of the group on the feeder, I'm thinking I will have to take it at 125%, then question # 2 is: I will be hooking the pool pump motors up to 240 volts ( approx. 6.4 amps), but they are also able to run on 120 volts ( 12.8 amps). I thought I read somewhere in the code that I would have to figure the load up on the largest available rating, which would be 12.8 amps. Am I correct in this and if so could someone give me the code reference? I can't seem to find it. Maybe I read it wrong, but this has been my understanding. Thanks again. ..Steve

 

[iwire]

# 2 is: I will be hooking the pool pump motors up to 240 volts ( approx. 6.4 amps), but they are also able to run on 120 volts ( 12.8 amps). I thought I read somewhere in the code that I would have to figure the load up on the largest available rating, which would be 12.8 amps.

Am I correct in this

No, you are not.

You most definitely calculate the load based on the voltage you are using.

If someone comes along later and wants to rewire the pump for use at the lower voltage they will have to up size the conductors at that point.

 

[RUWired]

Rick, I seem to be missing 2 things here. First if the hot tub motor is the biggest motor of the group on the feeder, I'm thinking I will have to take it at 125%

The hot tub data plate already has the 125% motor load figured in.
Article 430.24 states that you take the motor load plus the other loads. The hot tub is the other load.

430.24 Several Motors or a Motor(s) and Other Load(s)
Conductors supplying several motors, or a motor(s) and other load(s), shall have an ampacity not less than 125 percent of the full-load current rating of the highest rated motor plus the sum of the full-load current ratings of all the other motors in the group, as determined by 430.6(A), plus the ampacity required for the other loads.

If the pool pump was incorporated in the hot tub control circuit, then you would have to size the motors to the highest rated.But these are seperate items.
Rick

 

[augie47]

Motor HP

Motor HP

Bob NH,
When I first read your post, I had a "brainflash". Having seen several of similair situations where the customer purchased a high HP air compressor only to find it pulls current of a 1 hp (I understand the how and why of the rating), I wondered how it is addressed by NEC since our calculations are based on the tables in 430 part XIV and based on horsepower. The more I thought about it, I don't recall any of these motors themselves that were marked with HP, just amps/volts. The HP was displayed on the compressor/pump itself. Don't kmow how they got by 430.7 (a) (7).

 

[Davis9]

Bob NH,
When I first read your post, I had a "brainflash". Having seen several of similair situations where the customer purchased a high HP air compressor only to find it pulls current of a 1 hp (I understand the how and why of the rating), I wondered how it is addressed by NEC since our calculations are based on the tables in 430 part XIV and based on horsepower. The more I thought about it, I don't recall any of these motors themselves that were marked with HP, just amps/volts. The HP was displayed on the compressor/pump itself. Don't kmow how they got by 430.7 (a) (7).

Manufacturers often list a "developed horsepower" on Air compressors. Kind of shady but that is how it is done.

Tom