Help needed no knowledge

[eil]

The motors look slightly different, but are they the same make?, do they have a rating plate that is readable as it could tell you what size capacitors it requires. Do you have a sparky mate that has a capacitor tester to test them for you, otherwise you could go to your local motor re-winds place and ask them to give them a once over, they would be able to tell you what caps should be on them more than likely.
When you run the one that works , when it gets up to cut out pressure does the switch hiss when it cuts out, as its then that the pressure switch is supposed to unload the pressure from the compressor discharge pipe.

 

[chrisf1]

No the motors are not the same make the one that works is the proper one Airmark 3HP the other that has the capacitor missing is a CEG 3HP single phase and I have not managed to get that running and that one I think will be replaced but I want to get the working one working properly first. I cannot be sure about the hiss from the working one but as I said earlier when I undid the pipe from the switch there was definitely no air getting by. I will check for the hiss tomorrow now I know it does cut out. Thanks Chris

 

[eil]

I take it that when you were switching the compressor off you were switching it off at the pressure switch and not at the mains, when you switch the pressure switch off it then automatically unloads the discharge pipe, if you switch it off at the mains it doesn't unload the pipe.

 

[chrisf1]

I am pretty sure I have done it both ways but tomorrow I will listen for the hiss thanks Chris

 

[wyn]

Hi WYN and thanks for your reply should I attack this tomorrow and undo those pipes you have circled in the middle or should I bite the bullet and replace the black control box this is unknown ground for me if I should go to the valves in the centre are they replaceable consumables or just likely to be bunged up with crap and want cleaning if it is cleaning any recommendation of cleanser. Thanks Chris

If you are going to be using the compressor for a couple of years, i'd be tempted to have a bit of a poke around and check things like these non return valves are ok. Just clean with a rag ....solvents might not be good for the valves if they are some sort of rubber. But these valves are probably not the problem.

As Eil says, you really want to see if you get a "hiss" when the pump stops, which will tell you if the unloading valve is working.

 

[chrisf1]

Hi again everyone just been down and run it again it takes about six mins to cut out and it does hiss, I then opened the tap to let out the air for about 90 seconds and it tried to start again but just doesn't quite make it i let it have a few attempts as the air tap was still letting out but I got worried after seeing it struggle for about 20-30 sec that something would fry so I unplugged it. Anyone got any ideas where I go from here thanks Chris

 

[rtbcomp]

Daft point - does the hiss come from the pressure switch that the motor is actually connected to? If it's the other one hissing there may still be a fault with the one in use.

Set the knob to "off" on the one not in use.

 

[chrisf1]

Yes it comes from the one running thanks Chris

 

[rtbcomp]

Are you running it off an extension lead? If so there may be a voltage drop on start-up, try connecting as close as possible to the mains.

 

[chrisf1]

I am running it off an extension lead and I will try that later because I have just removed the smashed pressure gauge to make sure I ordered the correct one. That is something that never entered my head and I don't think it will be the cause but got to be worth a try. Has anyone any ideas about this drain plug underneath because I can turn the nut either direction and it does not tighten or loosen and is still air tight and I really need to drain this

 

[rtbcomp]

It may an automatic one, they spring open when pressure drops to about 5 psi. Does it feel damp or is there a damp patch on the ground beneath it?

You may have to remove the whole thing from the tank to examine it.

 

[chrisf1]

It may an automatic one, they spring open when pressure drops to about 5 psi. Does it feel damp or is there a damp patch on the ground beneath it?

You may have to remove the whole thing from the tank to examine it.

Hi again that is what I was trying to do remove the whole thing I have been undoing the only nut I can see which has a knurled piece protruding from the centre and the nut acts like a stripped thread, it turns either way without coming loose and it is still airtight, if you can make sense of that you are a better man than me Gunga Din. As for your suggestion about the extension lead you were spot on I plugged it directly into the mains and tried again and everything was hunky-dory, So I now have one side working as it should the other side I am sure has been seriously molested there is no cover for the starter control, also it appears to be missing a capacitor and the reset button has melted and wires in the box on top of the motor appear to have got hot enough to melt slightly in places. So with this side I could well be needing another motor if anyone has one please contact me or if anyone has suggestions about this side lets hear them. I think when this compressor is up and running as it should be it will be one serious bit of kit.Many thanks everyone Chris

 

[rtbcomp]

That's good - progress at last!

That nut sounds weird, I take it you have a spanner on the outer bit and it just turns. Have you tried holding the nut with a spanner and turning the central bit with pliers &c?

You should get a new motor off ebay for £80 -£100, check the rating plate on the one that works and get another to the same spec. If you can't get one with the same shaft size get a standard 24mm shaft and a new pulley from Machine Mart.

 

[chrisf1]

Well now I had the same thing happen this morning but maybe it was because there was air in the cylinder, I switched it off from the mains drained the air restarted, run untill cut out, let the air out until it restarted which it did fine. Also I have removed the knurled knob and some black nasty gunk dripped out but not as much as i was expecting I have attached some pics of the knurled tap, should this be removed all the way or just loosened because the tank is is still airtight with it completely removed

 

[rtbcomp]

Did you just switch it on at the mains? You should make sure the knob on the pressure switch is "off", apply the mains and turn the knob to "on". This will ensure the delivery pipe is empty.

Try poking a bit of wire into the drain valve, it's probably blocked with muck.

To drain the tank you only should have to loosen the knurled knob.

 

[chrisf1]

Yes understand I should only have to loosen it but how is it still airtight with it removed completely. I don't remember which way I turned it on but it worked OK when I went through the proper sequence, thanks Chris

 

[rtbcomp]

.....but how is it still airtight with it removed completely..........

Try poking a bit of wire into the drain valve, it's probably blocked with muck.

 

[chrisf1]

Try poking a bit of wire into the drain valve, it's probably blocked with muck.

Hi again RTB you have been the best help I could have hoped for with this machine but I have just got back from the ale house and will not be going near the garage till tomorrow but you have my greatest thanks and respect for sticking with me through this, imagine anyone new looking at this thread 4 pages and still got another pump, starter. and motor to go.By the way have you a name I can call you it feels distant RTB and by now we are bessy mates, thanks Chris

 

[chrisf1]

Today I have taken the motor from the working side and fitted it to the other side and the pump ran up to pressure without a problem so it seems that what I will need to get the other side working is just the motor and pressure switch. The motor is a single phase GEC 3.5 hp 2800 rpm with a 28mm shaft with a 5.5 inch pulley, I was talking to someone the other day who asked me if the capacitor was alright this is when I found it was missing and when I opened the plastic box on top of the motor which I assume is where the capacitor lived there were 2 wires floating one with a spade connector and the other without which I have also assumed are for the missing capacitor, anyway my plan over the next few days is to take the motor to be tested where I don't know suggestions welcomed I am in Kent UK as it might be a new motor is not required just a capacitor which will make it a lot cheaper but everything considered things are looking good, I managed to drain the water about 2 gallon as RTB said sticking a bit of wire up it did the trick. Thanks everyone for your help and please let me have any suggestions on this motor and missing capacitor Chris

 

[rtbcomp]

Look under Electric Motors in Yellow Pages, I'm sure you'd find someone to give a free test & estimate.