ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Recent Posts
Al Hildenbrand - Minneapolis - obituary
by bcpappas - 02/02/23 08:01 PM
by renosteinke - 01/27/23 09:52 PM
Does NEC 551.71 (F) apply to dwellings?
by BigB - 01/20/23 10:46 AM
Power submeter connections
by HotLine1 - 01/19/23 09:09 AM
New in the Gallery:
Burger King crown sillyness
Burger King crown sillyness
by wa2ise, December 11
240/208 to a house
240/208 to a house
by wa2ise, October 9
Who's Online Now
0 members (), 24 guests, and 20 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
#187735 07/08/09 07:35 AM
Joined: Jan 2005
Posts: 65
petey_c Offline OP
Got a service call while at a supply house. Older man said that his pump (1 HP 120 VAC Hayward) had tripped his GFI and wouldn't reset. So he changed the GFI and it still tripped. Okay, I figured that he installed it incorrectly. Got to his house and it was a dedicated 15 amp circuit with the GFI wired correctly. PVC pipe from the panel, to a switch, then to the box for the GFI. Here's what transpired: changed GFI, still tripping. (Initial start current 17.5 amps (for about half a second), then settles down to 10.8). Ran temp 14/2 from panel to GFI, still trips. GFI in garage runs pump without tripping. Gremlins or...? Thanks, petey.

Joined: Jul 2002
Posts: 8,432
Likes: 3
You own a Megger?
What I would do is disconnect the motor, open the terminal box up, disconnect the C-switch and megger the Start and Run windings to Ground.
That should give you an idea of what is going on there.
It sounds to me like you have a winding down to Ground within the pump motor.

With it being a 120V motor, you should only use a 250V megger test.

Hope this is of help.

Joined: Jan 2005
Posts: 65
petey_c Offline OP
Trumpy, I'll borrow a megger from my other job. This pump is only three years old. We thought it was probably going south due to all the rain we've had here this past few weeks, but when it didn't trip the other GFI... I just didn't want the customer to spend $400-500 for a new pump to have the same problem arise.

Joined: Jul 2004
Posts: 9,788
Likes: 14
If it was water I would expect the problem to clear if you ran the pump for a while ... at least until it rains again.
I know the drill I use to mix mortar and grout will trip the GFCI if I get it a little wet but if I take it to a non-GFCI and run it for a minute or two the problem goes away. wink

Greg Fretwell
Joined: Apr 2002
Posts: 7,333
Likes: 7

Hang on a sec...
You said the pump runs from another GFI in the garage??

Did you check the switch, etc wiring without the pump plugged in? And the conductors in the PVC?

Does he have a straight blade male cap on the Hayward pump? AG pool pumps are factory (Hayward) with twistlock!

The GFI is a GFI receptacle at the pump location?

Joined: Dec 2002
Posts: 330
I am sorry to ask this, as I am sure you have already thought of it, but does the GFI that the pump will run on trip using the test button on it?

Joined: May 2007
Posts: 169
Sounds like the GFI in the garage could be bad. Try running a cord to the bathroom and/or kitchen, assuming they have GFI's.

Joined: Jan 2005
Posts: 65
petey_c Offline OP
This is why I thought of gremlins...: Dedicated 15 A 120 VAC ckt. to SP switch to GFI (GFI 1) near pump location. Changed customer supplied GFI (GFI 1 to my own GFI 2) - still trips. Runs okay on another (older) GFI (GFI 3) in garage on extension cord. Bypassed switch - still trips. Bypassed entire run from panel to GFI, still trips. Changed breaker (getting desperate...) - still trips. Runs okay on non-GFI receptacle (and draws 17 + amps for a half a sec or so). Ground and neutral connections good. Replaced GFI 3 with GFI 2 and it runs okay. (cue spookey music....)Thinking about going to a GFI breaker....

Joined: Mar 2006
Posts: 30
Petey, I think that the 1HP pump at 115V should be on a 30A breaker, but the system might squeek by with a 20A breaker. I don't think that its a ground fault issue. The #14 wire is ok, but my Square-D motor sizing chart says that the breaker should be 30A.

Below is a link from Square D so that you can download an IEC Motor Data Calculator and other small but helpful product selection programs. Hope this helps.

Joined: Jul 2004
Posts: 787
When you tested the pump with the first and second GFI in the garage(GFI 3 & GFI 2), was the pump still connected to the pool water? Perhaps the ground leakage path is thru the pump shaft, into the pool water and to earth via the pool ...

Obvious question: Can you verify the connection between the ground pin of the pump cord plug and the pump & motor case?

Page 1 of 2 1 2

Link Copied to Clipboard

Tools for Electricians
Tools for Electricians

* * * * * * *
2023 National Electrical Code (NEC)
2023 NEC Now Available!
* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman


Member Spotlight
Blue Collar Country
Posts: 5,370
Joined: January 2005
Top Posters(30 Days)
BigB 4
triple 3
Popular Topics(Views)
303,003 Are you busy
232,028 Re: Forum
216,769 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.5