Fuse keeps blowing on foam brush

[slash007]

The fuse for my foam brush keeps blowing on my Jim Coleman SS stand. It's been doing it every few months and I put in a new fuse and good to go for a bit. Today It blew the replacement fuse instantly. I had a spare motor so I replaced it thinking maybe that was the issue, but still blew the fuse. What could cause it to do that? The motor looks fine and doesn't turn on for even a second before the fuse blows. Thanks.

 

[MEP001]

Last timeI dealt with a Coleman unit I just bypassed the fuses. I had replaced them with slow-blow but after a while those started blowing too.

 

[slash007]

Last timeI dealt with a Coleman unit I just bypassed the fuses. I had replaced them with slow-blow but after a while those started blowing too.

You just wired it direct? There has to be a reason for fuses blowing. So far they have been very reliable. Zero blown fuses in 6 years at one site, and only this FB fuse issue here at this site after 10 years.

 

[Toms PTcarwash]

The fuse is of course there to protect your wiring, relays etc. If it started to blow on occasion, maybe the relay or motor starter has some bad contacts and is increasing your current flow.
Do you own an amp probe? If so, read the current before the fuse and see if it jumps up when the motor is energized.
You could go to a slow blow fuse, but if the wiring gauge is not sufficient to handle the full current of the breaker suppling the power from your panel, it's a really bad idea to eliminate the fuse.

 

[Dan kamsickas]

What devices are downstream from the a fuse? One of those devices is failed/failing or the wiring to it is shorting out.

 

[slash007]

What devices are downstream from the a fuse? One of those devices is failed/failing or the wiring to it is shorting out.

I assume the IDX MX10?

 

[MEP001]

You just wired it direct? There has to be a reason for fuses blowing. So far they have been very reliable. Zero blown fuses in 6 years at one site, and only this FB fuse issue here at this site after 10 years.

I've seen it happen over and over. I don't know why it starts blowing fuses, but it does. It seems completely random, it might pop the fuse immediately after I change it, or it might work for a week or a month or a year. The last wash I looked after that had Coleman equipment did the same thing, I blew all the spares I had and had to run a wire to bypass for the foam brush to work for the weekend, and it's still bypassed. The motor is thermally protected and the wiring is more than heavy enough to withstand anything other than a dead short. Usually changing to a slow-blow 10 amp fuse (here) solves it, but this one kept doing it. Motor load-tested fine.

 

[MEP001]

What devices are downstream from the a fuse? One of those devices is failed/failing or the wiring to it is shorting out.

1/3 HP motor running a Procon pump.

 

[Dan kamsickas]

I've seen it happen over and over. I don't know why it starts blowing fuses, but it does. It seems completely random, it might pop the fuse immediately after I change it, or it might work for a week or a month or a year. The last wash I looked after that had Coleman equipment did the same thing, I blew all the spares I had and had to run a wire to bypass for the foam brush to work for the weekend, and it's still bypassed. The motor is thermally protected and the wiring is more than heavy enough to withstand anything other than a dead short. Usually changing to a slow-blow 10 amp fuse (here) solves it, but this one kept doing it. Motor load-tested fine.

1/3 HP motor running a Procon pump.

Ahhhh, the joys of carwashing.

 

[slash007]

1/3 HP motor running a Procon pump.

I thought that's all it was. I've had the exact same experience. Couple of times it blew instantly, other times I'd get weeks or almost a year. I'll bypass as a quick test.

 

[slash007]

I've seen it happen over and over. I don't know why it starts blowing fuses, but it does. It seems completely random, it might pop the fuse immediately after I change it, or it might work for a week or a month or a year. The last wash I looked after that had Coleman equipment did the same thing, I blew all the spares I had and had to run a wire to bypass for the foam brush to work for the weekend, and it's still bypassed. The motor is thermally protected and the wiring is more than heavy enough to withstand anything other than a dead short. Usually changing to a slow-blow 10 amp fuse (here) solves it, but this one kept doing it. Motor load-tested fine.

that link you sent is for fast blow. I haven't had any luck finding 10 or 15am 125v slow blow. Any other links by chance?

 

[MEP001]

Sorry, I didn't check. I had tried the 10 amp after the original 6 amps started blowing, figured it would be okay since the motor is rated 8 FLA.

I'm sure I ordered some 8 amp slow blow from either Mouser or Digikey, but I can't find them.

 

[slash007]

I just put in a 10amp fuse I found sitting around and it worked, but of course no idea if it's the fuse or because it decided it wanted to work for a day/week/month. Guess I'll find out. Thank you.

 

[Blanco]

The fuse on the coleman super saver units for foam brush needs to be a 10 amp fuse. The reason why you want a 10 amp and not a 8 amp is because the FLA of the motor is 8 amps. You want a fuse with a 20% more capacity. If you blow the 10 amp fuse then you have either bad motor (most likely), bad pump (causing motor to overheat/jam), or bad wiring from the electric motor to the control cabinet/fuse.

 

[slash007]

I calls for a 15 amp fuse, but so far the 10 amp has been holding up. Not sure why the 5amp lasted so long then.

 

[MEP001]

They put 6 amp in them, maybe because at the pressure they recommend it shouldn't ever exceed that. I don't know where you saw it calling for 15 amp, but if it's factory marked on the fuse holder that's probably the biggest fuse it can handle.

 

[slash007]

They put 6 amp in them, maybe because at the pressure they recommend it shouldn't ever exceed that. I don't know where you saw it calling for 15 amp, but if it's factory marked on the fuse holder that's probably the biggest fuse it can handle.

Nothing official, just written in marker pointing to the fuse holders, so maybe the installer. All others had 15amp fuses in them. Good to know it's not needed.

 

[Blanco]

Even though the FLA is 8 amps does not mean your motor draws 8 amps 100% of the time. The current drawn during normal running operation is somewhere between 20% to 30% less than the FLA. Most electric motors are designed to run at 50% to 100% of the FLA. As a motor wears out the amount of current it draws will increase. It will run hot and become less efficient. That is why your 5 amp fuse may have worked for a period of time. A 15 amp fuse is way overrated and almost twice the FLA rating. If you blow a 10 amp fuse which is 20% more amps than your FLA, then you most definitely have a problem with your motor, pump, or wiring.

 

[PDonnelly]

Are all of your wiring connections tight and clean? Is your relay/starter chattering? Are the contacts on the starter clean, dirty or fowled connections can cause and major increase in amp draw or cause the contact plates to not seat together correctly and cause for air gap in between the contact plates. is there any chance your pump itself is getting air bound or "locked up" slightly causing the motor to have to work even harder at start up to get the pump moving which would definitely cause for a longer starting amp load? Not familiar with your unit but definitely somethings to consider ....

 

[mjwalsh]

What devices are downstream from the a fuse? One of those devices is failed/failing or the wiring to it is shorting out.

FWIW ... at one time I was dumb enough to think that rubberized coils on chemical solenoids were 100% waterproof. They are not .. & the rubberized coils have been known to cause a fuse to blow intermittently.