Fuse problem

[esn13_jrr14]

Original Blown Fuse - NON 20 amp 250V

New Blown Fuse - NON 20 amp 250V

I seem to have an issue with blowing fuses. I have a GFCI breaker on my main box at my house which leads out to the box seen in the pictures above. I replaced my pump this year. It's a 1HP Super Pump running on 120V. The original blown fuse was used all last year after we bought the house. It ran for over a month and a half at start up this year. I replaced the fuse after work last night around 6PM and woke up this morning to it being blown.

Does anyone have any idea why the new fuse blew so quickly? Do I need to switch to a FRN fuse?

Of course I'm supposed to have a 4th of July party so I want to try and get this resolved.

Thanks!!!

 

[cramar]

Those pics aren't working, regardless, if you keep blowing fuses you don't have a fuse problem you have a capacity problem in that there is too much load on the circuit.
What size wire is it?
How long is the wire run?
What items are on the circuit? Just the pump? Anything else?

20 amps should be enough to run the pump, don't start putting larger fuses in, that can be dangerous.

 

[JohnT]

Make sure you don't have a loose connection anyplace. Motors try to run regardless of what's going in, and they draw more current if the voltage goes down.

Is it tripping when the motor starts, after a long run, or randomly?

 

[esn13_jrr14]

Original Blown Fuse

New Blown Fuse

The pictures should work now.

I'm not sure of the gauge of the wire. The pump is the only device on the circuit. The run is probably between 75' and 100'.

I'll check the connections again. I checked them at the box outside before I put the fuse back in and everything was secure.

It just randomly tripping in my opinion. I don't have a timer yet so the pump constantly runs. It ran all last summer and for a month and a half straight this year, then tripped. The new fuse was installed last night at 6PM and blew sometime in the middle of the night.

Does anyone have any thoughts on NON vs FRN fuses for motor applications? The only reason I used NON is that was what was in use already. The packaging for the NON fuse said to use FRN fuses for motors, however.

Thanks for the help everyone!

 

[Bama Rambler]

If it ran all last season and 2 months of this season and wasn't blowing the fuse, I'd start looking for something else besides the fuse.

Have you checked the amp draw of the motor?
Have you tried to spins the motor by hand to see if a bearing is dragging?

 

[esn13_jrr14]

I reached through the strainer basket area and spun the impeller and it wasn't dragging, in my opinion.

I'll check the amp draw of the motor next, that makes sense.

I'm starting to wonder if I nicked the wire when I replaced some of the plumbing when I opened this year. I had to dig around the wire to get to the plumbing. The wire is only a couple inches underground. I'm just wondering why it's been OK until now. The only thing I can think of is we've had a couple torrential downpours the past couple days, maybe the ground became over saturated and if the wire was nicked it shorted? I guess I'll check that too...

 

[JohnT]

The lower clip for the fuse is discolored. Normally I'd chalk that up to corrosion, but the one right next to it is shiny. That makes me think that holder is running hot more than just occasionally. Lugs look the same way. Can you swap over and use the other fuse holder?

The FRN fuse is a better choice, but it really only has an advantage in tolerating motor start-up current, and that isn't when you are seeing the problem.

If you had nicked a wire you'd be tripping your GFCI.

 

[esn13_jrr14]

I dug up around where I thought I potentially nicked the line. The line was in perfect shape, no nicks, burns, or damage.

I then checked all of my connections, first from my panel to my safety switch, in the safety switch, then from safety switch to pump. As John recommended, I switched over to the right pole and I used a FRN fuse. The pump has been running since 7PM last night with no issue. Hopefully the problem is fixed!

 

[RobbieH]

There are breaker fuses you can use to replace those, that way you won't have to keep buying more while you hunt down the problem.