Blowing fuse

[DestroyItYourself]

I used my wolf dakota 150 compressor the other day with no issues. It was about -2 earlier when I went to use it, every time it's switched on it blows the 13amp fuse,.I hear it trying to start for a couple seconds then nothing. Emptying the tank made no difference. Anyone had issues using compressors in the cold? A mate reckons it could be the capacitors or the motor? First time it's given me any hassle in a few years.

 

[carbon]

If a capacitor has failed it has the same symptoms that you have described. If it’s belt driven remove the belt and try again. But a capacitor that hasn’t completely failed will potentially start a motor that has no load on it. If possible check the capacitance of the capacitor and compare it to the value marked on it.

 

[Robotstar5]

The oil may have thickened up due to the low temp, try warming the casing with a hot air gun/hair dryer.

 

[Pete.]

I used my wolf dakota 150 compressor the other day with no issues. It was about -2 earlier when I went to use it, every time it's switched on it blows the 13amp fuse,.I hear it trying to start for a couple seconds then nothing. Emptying the tank made no difference. Anyone had issues using compressors in the cold? A mate reckons it could be the capacitors or the motor? First time it's given me any hassle in a few years.

That's pretty much how min went turned out to be a cooked winding. I took the motor off the pump and tried it and it still blew the fuse so it went in the skip.

 

[DestroyItYourself]

I'll have a play about with it today, fingers crossed. Anyone know what the oil capacity is for the dakota 150l? Cheers for the help

 

[Barking Mat]

I'll have a play about with it today, fingers crossed. Anyone know what the oil capacity is for the dakota 150l? Cheers for the help

Do you have a sight level or dipstick on the filler?

 

[DestroyItYourself]

There is mate, but it's a git to see properly

 

[DestroyItYourself]

Got the belt off, the motor spun alittle then popped the fuse.

Edit, had it spinning abit longer. Unplugged, tried again and it popped the fuse

 

[DestroyItYourself]

Can't edit

Will get a volt metre on it and check the capacitors.

 

[dobbslc]

My compressor had the same motor with the same fault, it was toast and I had to buy another one.

 

[DestroyItYourself]

Blue capacitor that is 300uf + or - 15% reads 313 with and 315 with terminals other way.

White capacitor that is 40uf + or - 5% read 40.05uf both ways.

I guessnthe motor is dead?

 

[Pete.]

Blue capacitor that is 300uf + or - 15% reads 313 with and 313 with terminals other way.

White capacitor that is 40uf + or - 5% read 40.05uf both ways.

I guessnthe motor is dead?

Probably. What size motor is it?

 

[DestroyItYourself]

3hp

 

[carbon]

If the motor has a centrifugal switch, that could be stuck with the contacts closed and not switching the start capacitor out. Ideally check the insulation with a pat tester to confirm the motor is serviceable or not

 

[DestroyItYourself]

There's a place in edinburgh that will inspect for free , I'll give that a try. Failing that I'll need to find somewhere for a like for like replacement, any suggestions ???

 

[Dragnet]

Centrifugal switch is easy to check. Start it and listen for a click from the motor a second or two after startup. That'll be the switch operating, bringing the startup capacitor out of circuit in favour of the run capacitor. If no click, the switch could be welded as carbon says. If you can take the plastic end off it might be visible. Prise the contacts apart, dress the damaged portion and it'll be fixed. Motors are less likely to have these switches these days, so I'd think the capacitors are the most likely culprit.

The capacitors could be toast, as they do have a finite number of cycles. If you have a multimeter, you can check their resistance as a simple test (out of circuit, no power). It ought to be close to infinite (in the megohm range). If not, they're toast. Get some new ones from any motor shop (of which there ought to be plenty in Edinburgh). If you have a mains rated switch handy, and some wiring skills, you can wire the start capacitor in series with the switch. Turn the motor on with the switch on, then after a couple of seconds turn the switch off to remove the startup capacitor from the circuit. If the run capacitor is still OK, the motor will continue.

The startup capacitor in particular has a hard life, which is why they have ratings for starts per unit time. You really don't want the motor kicking in less than once a minute, as the startup capacitor doesn't have time to recover and its lifetime is shortened. It's best for the motor to start fewer times and run for longer periods than it is to have it keep starting and stopping. You could adjust the lower bound of the pressure switch so that it has to be 'on' more per pressurising cycle.

If the motor itself is broken (least likely possibility), rewinding is possible and may be cheaper than a new motor. New motors are interchangeable based on standardised sizes and formats, so the place that you intend to get yours tested will help you. Any that is the same rating and mounting type as yours will work the same.

 

[bourbon]

There's a place in edinburgh that will inspect for free , I'll give that a try. Failing that I'll need to find somewhere for a like for like replacement, any suggestions ???

 

[Dragnet]

Blue capacitor that is 300uf + or - 15% reads 313 with and 315 with terminals other way.

White capacitor that is 40uf + or - 5% read 40.05uf both ways.

I guessnthe motor is dead?

I missed this post. Using a standard multimeter capacitance measurements are pretty useless as they're not taken at working voltage. Often components can measure OK but fail under load. Try a resistance test as I mention above, which may reveal something, but again is done at the internal voltage of the multimeter's battery. I have a tester I built to enable load-testing of capacitors to demonstrate leakage at working voltage, but without that you're really into swapping and testing territory, or visiting the testing outfit you mentioned.