2 hp pool motor

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adagys

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i have a 2hp pool pump which is located approx 25 feet from an above ground pool that keeps tripping the 20A gfi breaker on start up. The motor states it draws 15A. Should I put this pump on a 30Amp breaker? It is 115V.
 
Do you have a ground fault problem or an overload problem?
Voltage drop? (Distance problem)
 
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Sounds like a pool pump problem. The GFCI is doing it's job. You can try replacing the GFCI, for testing only, with a standard breaker,with nobody in the pool. If the pump trips then it is tripping on overload. If it runs then there is something leaking in the pump that is causing the GFCI to trip-- Either case I believe you have a bad pump. You can try a new GFCI and see but I bet it will still trip.
 
Dennis Alwon said:
... The GFCI is doing it's job. You can try replacing the GFCI, for testing only, with a standard breaker,with nobody in the pool. If the pump trips then it is tripping on overload. If it runs then there is something leaking in the pump that is causing the GFCI to trip-- Either case I believe you have a bad pump. You can try a new GFCI and see but I bet it will still trip.
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I have never done any troubleshooting on pool pump motors and Dennis likely has. Is the CB tripping on GFI or overload? Has the pump motor worked in the past on this CB - or is this startup?

I ask because ...
adagys said:
... The motor states it draws 15A. Should I put this pump on a 30Amp breaker? It is 115V.
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ada -
Go look at the motor rnameplate again. 15A for a 2hp 115V motor is really low. I would expect 20A to 25A. A 2hp , 115V motor on a 20A cb is a heavy load. If it is not tripping on GFI, or this is startup (has not worked in the past), I'd consider a 25A or a 30A.

Just curious: What does the mfg installation say about the required circuit size?

cf
 
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the panel is only 7 ft away so I dont think I have a voltage drop problem.
Is it possible that its the motor on start up? The motor is uphill from the pool and it only trips in the morning with the initial start up. It is on a timer, and once it starts running it runs fine. I'm thinking that the water drains down overnight and the pump has to work harder at first to overcome gravity but then it works fine.
 
adagys said:
the panel is only 7 ft away so I dont think I have a voltage drop problem.
Is it possible that its the motor on start up? The motor is uphill from the pool and it only trips in the morning with the initial start up. It is on a timer, and once it starts running it runs fine. I'm thinking that the water drains down overnight and the pump has to work harder at first to overcome gravity but then it works fine.
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Has this pump been installed for awhile? If so then the pump has lost some of it's ability to do the job. If this is a new install I would put an ampmeter on it and see what is going on. I still think you will need to change the pump.
 
A 115V, 2Hp motor has an FLC of 13.6A according to Table 430.250.

Maximum LRC in accordance with 430.251(A) is 144A, that isprobably close but it decays to around 6 times the FLC is 81.6A, within 0.05secs, and sits there for maybe 3 secs.

You will need to look at the actual breaker trip curve for a single pole 120V breaker, and the motor starting curve and select the breaker that has enough space between the motor starting current and trip curve.

I plotted a generic motor starting curve with a 30A breaker. It shows that if the motor is up to full speed within 2-secs a 30A breaker may work. Need to check your nameplate and get some particulars.
 
kingpb said:
A 115V, 2Hp motor has an FLC of 13.6A according to Table 430.250.
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Kingpb, Table 430.250 says a Three Phase, 2HP, 115V motor will have a 13.6A FLC. Table 430.248 says a 2HP, 115V, Single Phase motor will have an FLC of 24A.

I don't think the question specified single or three phase, but it sounded like a residential installation (above ground pool.) I think the single phase motor would be more likely.
 
david luchini said:
Kingpb, Table 430.250 says a Three Phase, 2HP, 115V motor will have a 13.6A FLC. Table 430.248 says a 2HP, 115V, Single Phase motor will have an FLC of 24A.

I don't think the question specified single or three phase, but it sounded like a residential installation (above ground pool.) I think the single phase motor would be more likely.
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Just curious: when was the last time anyone has seen 115V, 3ph, 60hz?

cf
 
david luchini said:
Kingpb, Table 430.250 says a Three Phase, 2HP, 115V motor will have a 13.6A FLC. Table 430.248 says a 2HP, 115V, Single Phase motor will have an FLC of 24A.

I don't think the question specified single or three phase, but it sounded like a residential installation (above ground pool.) I think the single phase motor would be more likely.
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Ah, thanks for the catch.:)

I did however plot the correct 115V, 1-ph, 2Hp motor, so the breaker size still is valid. The 144 A max, LRC makes more sense now.

Although now I'm wondering if it is 115V 1-ph, or 230V 1-ph rated motor, because of the 15A on the nameplate, would seem low for 115V.

As far 115V 3-ph, never seen it....
 
The question specified a 20A c/b. I wonder what the circuit conductor size is? Table 430.248 lists a FLC of 24A for a 2HP, 115V, single phase motor. Per 430.6(A)(1) and 430.22(A), the minimum ampacity for the motor circuit should be 30A.
 
It appears step one would be to recheck your nameplate. A "true" 2HP motor on 115v is going to pull more than 15 amps, but pump folks are notorious for unusual HP ratings so your nameplate FLA may be the key.
In any event, if the breaker is being used as GFSC protection (as opposed to overload), IMO, it is undersized.
My first step, after confirming the data and assuring the motor have thermal OL protection, would be to check for proper amperage and if it is correct, try a 30 amp breaker.
 
Per 430.52, an inverse time c/b of up to 60 Amps can be used for the short-circuit ground-fault protective device (250% of 24 Amps.)
 
Cold Fusion said:
Yes, it certainly is - I've worked a few.

Just curious: What would that have to do with this thread?

cf
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Earlier I mis-stated something by using Table 430.250 at 115V. The question came up as has anybody ever even seen 115V 3-phase before.

You probably missed it if you didn't read all the posts..........:grin::grin:
 
david luchini said:
ColdFusion, someone asked the question whether anyone had seen a 115V, 3 phase motor. I think that is what the response relates to.
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Yes, that was me that asked. And no, the question related to "115V, 3ph, 60hz".

Caution - Rant following below. Recommend to delete before reading

I worded it that way because I've worked 400hz systems before and did not see any point is the discussion going that way since it would not have anything to do with the OP's question.

I'm not particularly on your (plural) case - there is a forum wide lack of most everyone not reading the threads before replying. Information is regularly repeated following previous posts. I guess I don't see much point in repeating something someone already said.

And another one that leaves me baffled is the general continued hammering of some particular point the OP is well aware of. Just recently there was a thread where the OP was asking about multiple AHUs on a 20A circuit. The Op stated yes I know it needs to be a 15A circuit - I have other questions. Nearly every replying post hammered the point the CB was the wrong size. Duh - I'll bet the OP already knew that.

Other than displaying an arrogant and demeaning nature, what purpose does this serve? And I personally believe most of the forum members are not purposely arrogant and demeaning

Rant complete - thank you for your time.

cf
 
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