Compressor blows fuse

[klaatu]

I've bought one of these:

http://www.axminster.co.uk/product-Axminster-AW30HP-3hp-Direct-Driven-Compressor-564885.htm

When I switch it on, it runs for a second or so, then blows the 13A fuse in the plug. I did get it to start once by holding the release valve open while it got going (that may have been a coincidence), and then it worked OK for the rest of the evening, but even that doesn't work now. I've now run out of spare fuses.

Any suggestions before I contact Axminster?

Steve

 

[irondarren]

Klaatu it sounds about right for a 3hp compressor to blow a 13amp fuse. you are running a 2.2kw motor which when it starts possibly draws as much as 7kw, which is about 25amps plus. In reality it should have a 16amp plug on it and be fused at the mains on a 20amp fuse. out of interest where are you running it from, ie how far from the consummer unit is it?

 

[klaatu]

It's in the garage (joined to the house), about 15m from the consumer unit. The wiring is all quite recent, this side of the house is a large extension built about 5 years ago.

 

[irondarren]

that distance should be to much of a problem, if you had said its in the shed at the bottom of the garden, it might have been different. out of interest was it supplied with a 13amp plug already on it? or did you have to put a plug on?

 

[klaatu]

It came with a 13 amp plug already attached.

 

[irondarren]

I suggest you contact axminster, if supplied with a 13amp then it should work on a 13amp plug, admittedly it will blow fuses on a regular basis (1 a month) because of the start up draw. they might try and give you some old flannel about the wiring of the house etc etc not being big enough, but have none of it if they try, there is a fault with the machine.

 

[klaatu]

OK, cheers.

 

[malcolm]

Are you switching it on and off using the red button above the regulator gauges like it says in the manual? That should give you a soft start with air bypass. Switching it on at the wall would result in big start current and blow the fuse.

If you're using the switch on the machine I'm with darren - sounds like the soft start could be broken

 

[klaatu]

Yes, I make sure the red button is off before switching the mains on, then pull up the red button to start it.

 

[lexi]

It`s a direct drive . Think they start with a thump and run faster. Looks the same unit as I had for seven years.

Alex

 

[rtbcomp]

If it hisses when it switches off the dump valve (soft start) should be OK. You're pushing your luck running 3 hp off 13 amps, as IronDarren says.

 

[oddball90]

My direct drive 3hp compressor runs off a 13amp plug no problems, even starting at the plug has not caused it to blow a fuse or trip the circuit breaker.

 

[rtbcomp]

My direct drive 3hp compressor runs off a 13amp plug no problems, even starting at the plug has not caused it to blow a fuse or trip the circuit breaker.

You're OK starting at the plug if the unit has been stopped for some time, the pressure in the pipe between the pump and the receiver will slowly lose its pressure due to leakage, and when it gets down to about 20 the dump valve in the black box will open anyway and release the remaining air.

 

[shenion]

I would think most compressors would have unloaders, mine has one. Bleeds off pressure in the pipe as soon as the pump turns off. No problem with 5HP on 20A outlet. Would probably run on a 15.

 

[rtbcomp]

I would think most compressors would have unloaders, mine has one. Bleeds off pressure in the pipe as soon as the pump turns off. No problem with 5HP on 20A outlet. Would probably run on a 15.

The Clarke range of Shhh compressors doesn't, the airflow is too low to close the valve and these compressors (freezer motors) will start under pressure. They operate at a slightly lower pressure than piston compressors.

My 3 hp Clarke compressor specifically says not to use it on a 13A socket, I have it on 16A socket with no problems, mind you, the MCB is rated at 30 amps.

 

[irondarren]

mine is on a 13amp plug with a bit of 6mm stainless as a fuse , but is 30amps at the breaker so is no probs

 

[klaatu]

I was tempted to put something a bit more um, resilient in place of a fuse, but it scares me a little.

In an case, I've had a thought, and I think I may have made a cock-up. It came with a little bottle part full of oil. I thought I was supposed to put all of it in, but I now notice that the oil level is above the half-way mark on the sight glass. It actually fills the sight glass. Presumably this could well account for it taking more power than normal to start up. I'm going to drain it down to the correct level and try again - once I find a 13A fuse. I have some fuses on order but they haven't arrived yet; local shop only had 3A and 5A, one of the joys of living on a remote island.

Steve

 

[irondarren]

15 amp fuse wire? in place of a 13amp fuse. done that before it works fine

 

[klaatu]

That occurred to me too a few minutes ago - drained the oil to the correct level, fitted 15A fuse wire - success! Feel a bit stupid now, but that's fairly common.

 

[irondarren]

15amp fuse wire will just give it that little bit extra it can draw on start up, possibly enough to stop it burning. well hopefully it all runs fine now and you get no more trouble