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View Full Version : Well pump fuses keep tripping, can't figure out why


mattward1
Oct 15, 2011, 02:10 PM
100 ft well. 6 weeks ago the 2 15Amp breakers started tripping periodically. Came to a head a few weeks ago when resetting breakers did not restart pump. Assumed (incorrectly I believe now) that the pump was bad, replaced with help from neighbors, 3/4 HP utilitech pump, 2 wire franklin motor. Had to fool with the pressure switch to get it to start but start it did, but would blow the fuse about once a week.

Pressure switch went bad last Sunday, though I would get smart and call a plumber, he replaced 30/50 with a 40/60. Nipple leading to the switch was pretty jammed up, had been there for quite some time.

New pressure switch blew the next day (Monday) plumber came back out to replace (another 40/60). THAT switch blew up the next day, another plumber came out and replaced with a 30/50, advised call an electrician.

Electrician was out Wednesday. Measured amps at breaker. Seeing variable startup surge, anywhere between 10 and 30 amps. Electrician was not sure if that was normal or not, everything I read indicates it is but I certainly don't know. He did replace the 2 individual 15 Amp breakers with a dual breaker. Went out to the well head and discovered that the grounding wire coming up from the pump had come out of the wire nut. Re-did that.

Pump and all has been fine for 3 days, laundry showers etc. Fuse tripped again today. Only thing I can think to do is pull the pump back up re-wire with a new wire. At wits end with this!

Any ideas?

jlisenbe
Oct 15, 2011, 04:08 PM
Matt, are you using buried cable? If so, then turn your breaker off and unhook the cable from the switch. Make sure the wires are not touching. Turn the breaker back on. See if the breaker throws. If it doesn't, then the problem is after the switch.

Sound like an above ground pump. Correct? If not, then did you replace the cable going to the pump in the well?

mattward1
Oct 15, 2011, 08:08 PM
Nope, submersible pump. We did NOT replace the cable going down to the pump, but we are going to tomorrow. Operation is intermittent, ran fine for several cycles this evening.

speedball1
Oct 16, 2011, 07:23 AM
Has anyone put a Amp-Probe on the cable to see how many amps the starting windings are pulling? Back to you. Tom

mattward1
Oct 16, 2011, 08:47 AM
Speedball, the electrician did use an amp-probe and we saw anywhere from 10 to 26 amps on startup, only long enough to flash across the meter (much less than a second, at least while we were watching it.) That's normal isn't it? I'm wondering if it's pulling that longer the times the breaker trips (when we're NOT watching it).

jlisenbe
Oct 16, 2011, 11:17 AM
It did this with both the new and the old pumps. For that reason, I don't think the pump is the issue.

mattward1
Oct 16, 2011, 12:13 PM
jlisenbe, I would tend to agree. The circuit initially tripped (for the first time in ~6 years) while we were on vacation (naturally). Was told by the neighbor that there had been a nasty storm the previous night. Possible the wire down to the well is damaged?

hkstroud
Oct 16, 2011, 01:52 PM
Before pulling pump, I would run a new cable (above ground) from switch to well head. If problem goes away replace cable to well head. If problem does not go away pull pump and replace wire down the well. Sounds like a lightening strike from six years ago is finally catching up with you.

mattward1
Oct 16, 2011, 02:15 PM
Everyone, thanks for all the input. I think I may have overlooked something pretty obvious:

The pump is short cycling. Just flushing the toilet (~3 gallons, right?) the pressure will drop from 50 to 30, and the pump will cycle, and a few more pounds will run off. The tank appears to be a 36 gallon (should hold ~15 gallons of water?) so clearly it's waterlogged or something(pressure was topped off when the switch was replaced.

Would this cause the motor to overheat and throw the fuses?

speedball1
Oct 16, 2011, 06:11 PM
the 2 15Amp breakers started tripping
You have 15 amp breakers installed and you pull 10 to 26 amps on start up and you wonder why they're tripping? Am I missing something here? Back to you, Tom

jlisenbe
Oct 16, 2011, 06:39 PM
Matt, if it's shortcycling, that needs to be addressed whether it solves the breaker problem or not.

To check this, locate the air valve at the top of the pressure tank. It's like a tire air valve. Push the stem and hold it for a few seconds. You should get nothing but air. If you get water, then the bladder is ruptured. The only fix is to replace the tank.

You can also do this. Let the pump get up to 50# and cut off. Once that is done, start running water into a 5 gallon bucket. You should be able to get at least five or six gallons out before the pump restarts.

Not sure what you meant by this. "pressure was topped off when the switch was replaced" Your tank pressure should be set to 28# when the pump is off and pressure is drained down to zero by opening a low level faucet.

mattward1
Oct 17, 2011, 06:41 AM
Hopefully this doesn't post twice...

jlisenbe I am going to look at getting the tank replaced today, will report back..

speedball1
Oct 17, 2011, 08:13 AM
Hey Matt,
Are you still using 15 amp breakers? Back to you, Tom

mattward1
Oct 17, 2011, 08:26 AM
Tom, yes we are. The startup surge we saw (and we watched about 10 or 15 pump cycles on the old breakers, and about 10 to 15 cycles on the new breakers. Both 15 AMP) was extremely brief and we did NOT trip a breaker while we were testing. All the reading I've done suggests that this is a normal condition that circuit breakers will deal with when attached to electric motors to overcome the initial inertia of (in this case) a pump that is not moving.(we're talking about tenths of a second I think) The observed surges were of a duration only long enough to flash a value on to the screen, after which the draw would immediately settle into about 8amp.

Do you believe my understanding is incorrect? To be clear (I know there is a lot of data) currently the system has been working for about 5.5 days. The fuse has tripped twice since Tuesday the 11th, once on Sat morning (during my shower) and when I went downstairs to reset it it tripped within 5 seconds of the pump running. Other than that it has worked in a house with me, wife and 2 kids (read: lot's of laundry).

Thanks for your input.

jlisenbe
Oct 17, 2011, 08:31 AM
Matt, my understanding is that breakers are designed to run at 80% of capacity for long periods but still tolerate a surge of 100%. If that is the case, then you should be OK with 30 amps.

This site had some discussion of the matter.

How to Size a Circuit Breaker | eHow.com (http://www.ehow.com/how_2314453_size-circuit-breaker.html)

speedball1
Oct 17, 2011, 08:47 AM
Hey guys! I'm no electrician but when I'm told the starting coils are pulling 10 to 26 amps against 15 amp breakers I think the first thing I would do is replace them with 30 amp breakers. And jlisenbve is the first time 30 amp breakers have been mentioned. Were they replaced or not? Back to you, Tom

jlisenbe
Oct 17, 2011, 09:26 AM
Wrong thinking on my part. I was trying to double the amperage for the double pole breaker. So you are correct in saying that two 15 amp breakers linked together will only supply 15 amps at 240 volts. So it could be that replacing the breakers would be a sensible and fairly cheap undertaking IF you have an understanding of how it's done. You would just need to be sure the breakers are matched to the wire gauge. 30 amp breakers would, as I understand it, require 10 gauge wire. But I'd feel better with an electrician's view of that.

speedball1
Oct 17, 2011, 09:50 AM
But I'd feel better with an electrician's view of that.
Then let's get one. We have top notch electricians right here on AMHD. I'll contact TK. Regards Tom

mattward1
Oct 17, 2011, 10:28 AM
OK good news/bad news

I've finally got someone out here who can test the electrical path competently.

The bad news: Wire running underground is bad. He's writing up an estimate now, I hope it doesn't make me cry. Tank is also waterlogged.

Thanks for all the input, I'll update as this becomes resolved.

jlisenbe
Oct 17, 2011, 11:08 AM
He can at least advise you on the breakers. Look at it this way... better than having a well pro install a new pump.