Amps for 3 x 5 hp pumps?

[Reese]

Yeah, we did kind of get sidetracked there, didn't we.  I guess I thought the first few posts resulted in "asked and answered", but Vinny's foot size and use of suction fittings is a bit off-topic.

[Bama]

you do know that 5hp rating your talking about is brake HP right.
They are 2.5 cont HP.  To run all 3 jetpumps you need more than a 50 amp service....talk to your dealer and see............

BIGPOPPA

Thanks BigPoppa....I misquoted, there are three 2.5 HP pumps.
My Bad.
Bama

[Bama]

Are you installing this breaker panel just for the spa-  connecting it into your existing main service panel?
 Or are you installing a whole new service panel for your entire home, and are asking what the size of your new electrical service into your home needs to be with this spa?
 With what you've posted, it's impossible to tell which one it is.  

If it's a whole house panel you're asking about, you can't just install a bigger capacity panel unless you have the feeds to your home evaluated and resized if necessary.
 
If it's just a spa panel you're installing, the required breaker isn't going to be anywhere near 100 amps (which is why I'm suspecting your asking about the main service panel vs a spa box).  Find out in your documentation what sized GFI breaker is required for your spa.  A very common requirment is 50 amps.  

In any case, based on your question and the way you asked it, it's evident that you may not posess the knowledge or skills to safely do this yourself.  Get a pro out there so you don't burn down your house or worse.  

 

You are so right, I don't have the skills nor the desire to wire it myself.   My husband is a good handy man, however for insurance purposes we always have professionals work on our home.  I just wanted to be more educated on the subject.  
We are installing a new service box, it is the amps I was inquiring about.
Thanks for your response, I appreciate it.
Bama

[Bama]

I think the important thing here is to go with the manufacturer's instructions. If they say this spa can run on 50 amps, then you can wire it that way.

 8-)[/quote

I think you guys are right, I'd better call the dealer to find out the recommended amps.
Bama

[Kyle]

2.5 cont 48 frame should run around 8-10 amps. If they are using 2.5 hp impellers.

They could slap 2 hp or even 1.5 hp impellers on the 2.5 hp motor and run lower amps.  I would just follow instructions and find out the flow rate in gpm for true performance.

[uncommonlytasty]

The reason that manufactures require a larger breaker then the actual current draw is because of the pumps inrush (startup) current load.  A 12 amp capacitor start motor can actually draw over 100 amps when started.  

[Bama]

Thanks all...
I checked with dealer and my tub requires 60 amps.   Our house currently has 350 amps, so we will allocate a service box just for the tub.  Also, I want the option to shut the power off from inside the house via small box in laundry room.  I don't want to walk out in a tornado just to shut the power off to the tub.  I live in a tornado prone area with lots of lightening...yikes!

Vinny, about those big feet of yours...do they stop up the return ducts of your tub? LOL

[Vinny]

Vinny, about those big feet of yours...do they stop up the return ducts of your tub? LOL

Luckily the intakes got some big screens on them ...

[Altazi]

I have an Artesian and it has 3 therapy pumps and a large circ pump and it does as spaman says - it turns off the heater if two pumps go on. I believe the most my spa draws is about 30 AMPS but it's been a while since I installed it.

cmon   30 amps running all 3 jetpumps?  Each jet pump is pulling at least 15 amps.....

There are 2 6 bhp pumps and a 3 bhp pump - half them for continuous - that's a total of 7.5 hp x 750 Watts/hp = 5625/220 = 25.57 amps ... ok maybe it's not half and maybe it should be 768 watts/hp but it's close! And my heater shuts off when 2 pumps are on. 4500/220 = 20.45 + (3x750)/220 = 30.27

Does that sound about right?

One hp = 745.7W, call it 746W.  One one hand, motors aren't 100% efficient, so they require more input power than the output power they deliver.  A reasonably high efficiency for a spa pump motor is 75%, so for 1000W input, you get 750W output; the remaining 250W is mostly waste heat.  If you are running a total of 7.5hp @ 75% efficiency, you would be looking at 7460W of electrical power, or about 32.4A @ 230VAC.  Likewise, your motors would be producing about 1.8kW of waste heat.

On the other hand, most motors aren't being run at their rated full load, so the overall current requirement is reduced.

Regards,

Altazi

[Vinny]

I have an Artesian and it has 3 therapy pumps and a large circ pump and it does as spaman says - it turns off the heater if two pumps go on. I believe the most my spa draws is about 30 AMPS but it's been a while since I installed it.

cmon   30 amps running all 3 jetpumps?  Each jet pump is pulling at least 15 amps.....

There are 2 6 bhp pumps and a 3 bhp pump - half them for continuous - that's a total of 7.5 hp x 750 Watts/hp = 5625/220 = 25.57 amps ... ok maybe it's not half and maybe it should be 768 watts/hp but it's close! And my heater shuts off when 2 pumps are on. 4500/220 = 20.45 + (3x750)/220 = 30.27

Does that sound about right?

One hp = 745.7W, call it 746W.  One one hand, motors aren't 100% efficient, so they require more input power than the output power they deliver.  A reasonably high efficiency for a spa pump motor is 75%, so for 1000W input, you get 750W output; the remaining 250W is mostly waste heat.  If you are running a total of 7.5hp @ 75% efficiency, you would be looking at 7460W of electrical power, or about 32.4A @ 230VAC.  Likewise, your motors would be producing about 1.8kW of waste heat.

On the other hand, most motors aren't being run at their rated full load, so the overall current requirement is reduced.

Regards,

Altazi

I was close!

And it was more than a year ago that I measured ...

[Tman122]

Thanks all...
I checked with dealer and my tub requires 60 amps.   Our house currently has 350 amps, so we will allocate a service box just for the tub.  Also, I want the option to shut the power off from inside the house via small box in laundry room.  I don't want to walk out in a tornado just to shut the power off to the tub.  I live in a tornado prone area with lots of lightening...yikes!

Vinny, about those big feet of yours...do they stop up the return ducts of your tub? LOL

But I am sure your code is going to require a shut off in site of the tub and no closer than 5 feet. And as a service guy I prefer it to be your GFCI breaker.