Source of replacement compressor pump/motor?

[gasket999]

Hi - We have a SiP Nimbus 25050 compressor in the basement (think its 8CFM and 50L)

The motor/pump packed up a few years ago when trying to use a propane cyl as an air receiver (too much work for the compressor).

It was mothballed and a replacement 14CFM compressor was bought.

Now I'd like to run tandem compressors (for extra CFM when shot blasting and also when painting to allow a dedicated comp to be kept outside for an air-fed mask). Luckily I have a 100a supply in the workshop so 2 comps'll work. Both comps filling the propane tank should give a hell of a good setup.

I don't like waste and rather than buying another compressor I would like to see if I can replace the motor pump unit on the SIP - ideally uprating to 14CFM at the same time.

The only reference I can find is a parts diagram here but this is just for the bog-standard 8CFM motor.

I was hoping that there would be some sort of generic pump/motor that would fit but the only one I can find is a piddly little 2hp one in the USA here

Fingers crossed this'll be yet another time when I just haven't a clue and a more knowledgable forum member can point me in the right direction.

Thanks folks.

 

[piman]

Hello Gasket,

Machine mart sell compressor s and motors. e.g. :- http://www.machinemart.co.uk/shop/search/filter/air-compressor-pumps-pumpmotor-units/type/any/module/shopcategory/page/1

Alec

 

[tigler]

Is the electric motor ok and what is it's power ?

 

[ford34/2]

Motor power/amps

My 14Cu FT ingersol has a great big diam Brooks 3 Hp motor, and of course the problems in supplying electric for a motor this size on single phase must also come into your equation.

Stan

 

[gasket999]

Hi guys,

pinman i did come accross the MM ones but assumed (maybe wrongly) that I'd need a complete motor/pump assembly, MM just have pumps in the compressor section.

The motor seems to be 2HP.

RE: the motor condition, I've just been out to check...

The compressor failed when my it was in the care of someone else, so i knew very little about what went wrong.

Just been out to check and the following happens:

when plugged in and switched-on, the compressor just hums but the motor fails to turn - you know that whine you get from electric motors when there isn't enough juice to move it or when something is wrong.

I removed the plastic shroud and turned the cooling fan with my finger (moves easily), when i do this the pump section seems to be moving plenty of air.

That being the case - is it likely that just the electric motor needs to be repaired/replaced?

I'd be happy with the 8CFM from the standard comp if it just means replacing/refurbishing the motor.

 

[tigler]

With the power disconnected, which is a very important safety precaution, turn the compressor by hand if possible. If it turns relatively easily with just slight resistance when the compressor passes compression stroke, then it's most likely the motor. The most likely cause of that problem is the motor run capacitor, start capacitor, or both if 2 are fitted. Without test equipment the only check you can make on the caps is a visual inspection, look for bulging and/or splits, either or both is a strong indication they have failed, although they may still have failed even if neither is evident. Replacement is the only solution, they can be had from Maplin for not alot.
Run caps will be between 3-100 MF at 370 or 440 volt, start caps will have a value above 70MF and for single phase motors a voltage rating of 250 or 330 volt. Most small motors, 2hp or below will just have a run cap.

 

[gasket999]

Thanks mate, seems very sensible advice.

I'vebeen out again and found that the cooling fan is directly geared to the pump so moving the fan is moving the pump. I can move the fan with one finger with very light resistance - feels like its moving nicely.

Based on your advice I called a couple of electric motor specialists. There's one that'll gladly take the whole compressor and test the motor for me (I'm pretty clueless about electrics). Notably the first thing they said after describing the symptoms is that it could well be a capacitor, before I said a word.

Great shout there mate. Many thanks.

 

[tigler]

Sounds like you have what is known as a direct drive compressor, so if it turns that easily it does indeed seem that the run cap has failed. Should be a cheap fix, a cap from Maplin is less than a tenner, installing should only take about 20-30 mins.
I did one only a few weeks ago on a direct drive compressor with exactly the same symptoms, new cap and all was good !
Just for information, modern caps don't last as long as the old oil filled type, which were made illegal because of the toxic oil they used for insulation. Modern caps use plastic insulation, known as dielectric, which breaks down in use and even deteriorates with time. This can cause them to fail quickly when put back into use after being unused for a time. I'm finding that modern caps need replacing after even a few years, whereas older caps can last decades. Some modern caps are better than others though, the Maplin ones are made in the UK and are very good quality.

 

[gasket999]

Fingers crossed! That'd be great if turns out I just need a small repair.

I'm taking it in on Tuesday I think, will let you know how it goes.

Thanks again.