Compressor Issue

[Crooky58]

I have air compressor which is new, which I brought back from Korea with me when I worked out there, I've cut the two pin plug off it and put on a UK plug on, when I plug it in it runs for a bit then the 15amp breaker on top of the motor clicks out, its a 220v air compressor - I can't call the manufacturer as they don't speak English and also a little far away, before anyone comes along and says its meant to cut out when the tank is full I know that and it does when it reaches pressure - its not that its I've checked the wiring can't see any obvious issues though it may be the capacitors but Im not an electrician - any ideas?????? or do I bite the bullet and buy a new motor for it……...

Simon

the breaker (which is 15amp)

 

[rtbcomp]

Does the motor sound as if it's labouring? What have you set the cut-out pressure to? Have you got the correct oil in it?

 

[Crooky58]

Hi Motor sounds ok, not sure what the cut out pressure is set too - its brand new so I would have thought its whatever the manufacturer has set it too, have checked oil on its dipstick it on it mark and what came in the compressor

 

[roofman]

What pressure does it hit before it trips?

 

[Crooky58]

I will check and post tomorrow thank you both for your help

 

[rtbcomp]

What is the power rating of the motor, I'm guessing 3hp?

My Clarke compressor started to struggle a bit at 150 psi, so I reduced it to 120 psi and it sounds much happier.

If the problem is due to the motor not being up to it then fitting a slightly smaller pulley on the motor may help, but you'll lose cfm.

 

[Crooky58]

Had a look a little while ago, can't really make out whats what to be honest! - it runs for about 14s then the trip cuts in - I tried to attach a video but can't, so i have attachedcouple of addition pictures with the spec plates on it - so annoying if only I had checked it before leaving Korea!

 

[normspanners]

Those cut outs are notorious for getting weak once they have tripped a few times I allways have them in stock now and if it starts trips apparently for no reason, in the bin they go.
If the compressor labours because of cold etc and they are close to popping it weakens them. You could also do an oil change that would do no harm
Best test would be to put a clamp on ammeter on the cable and see what its pulling .

 

[rtbcomp]

It's rated at 60 Hz so running it at 50 may cause it to draw more current.

If it only runs for 14s how do you manage to get it up to pressure? Do you keep resetting it?

One thing to make certain of is that you MUST make sure the knob on the pressure switch is set of "off" before attempting to start it. Set the knob to "off" apply mains and set the knob back to "on". You must repeat this after it has stopped due to the trip, just resetting the trip will make the motor try to start under pressure.

 

[migmug]

I had experiance of pillar drills supplied to the UK with 60Hz motors by mistake.

Have a read of this

http://www.engineering.com/Electron...wer-Supply-Frequency-Between-50-and-60Hz.aspx

I think the only fix is fit a new 50Hz motor, if you want the rated air delivery you also need a new pulley and belt.

 

[rtbcomp]

That's a brilliant link!

I remember working on a machine that had a 60Hz motor running on 50Hz. We fitted an extra cooling fan, although I think it just kept the cut-out cool!

 

[Crooky58]

Good link thank you, now I suppose the next question is what do I need to make it work - or is it not a viable option to change it!

 

[brightspark]

a clampmeter to check the amperage its drawing on start up and run would be worth knowing but it depends on what u have and how far u go other than that buy a 3hp motor for about 90 quid and change it

 

[rtbcomp]

As an alternative to a clamp meter those plug-in energy monitors will measure current.

 

[brightspark]

As an alternative to a clamp meter those plug-in energy monitors will measure current.

are they quick enough to measure inrush current though on start up

 

[rtbcomp]

^^ Pass!

 

[brightspark]

i have a clamp meter that picks up on motors but it wont take the reading of a 110v transformer turned on

 

[rtbcomp]

It's tripping a 15A breaker but not blowing a 13A fuse - may be worth trying a new breaker as Normspanners suggests.

 

[ford34/2]

Surprised it s not blowing fuses-- given the plate says 13.2 amps, Hope it has just got a 13 amp fuse in the plug.

It's tripping a 15A breaker but not blowing a 13A fuse

Stan

 

[brightspark]

a 13 amp fuse can take more start up current than a 30 amp b type breaker can on a 110 v transformer