Silent compressor problem

[davebParticipant @daveb17630]

I have a Bambi silent compressor. I used it recently for about 10 minutes and the compressor unit is running VERY hot. The oil level seems OK. Is this a fault or do they normally run hot?

Thanks. Daveb.

[davebParticipant @daveb17630]

Hot!

[pgk pgkParticipant @pgkpgk17461]

My dental compressor was bambi and I was never aware of it running hot.

pgk

[Trevor Drabble 1Participant @trevordrabble1]

Have you tried talking to Bambi in Birmingham ?

Trevor.

[Brian Sweeting 2Participant @briansweeting2]

Could be the compressor starter or capacitors at fault.

[RobinParticipant @robin]

Mine got horribly hot for no good reason I could see and stopped working. I bought another one. The hot one cooled down and worked for another 2 years, still going strong.

[Robert Atkinson 2Participant @robertatkinson2]

A company I worked for used lots of these and they should not run too hot to hold your hand on. Have you checked the oil level?
If that is OK the next thin to check is the capacitor (or thermal time delay relay if fitted, but most of these except the very small ones used a capacitor)

Robert G8RPI.

[Roger WoollettParticipant @rogerwoollett53105]

I have had this problem with a Bambi compressor. I decided the motor was only suitable for a quite low duty cycle. I had been using too much air and it got very hot.

Because of this the rubber diaphragm in the regulator failed. The first time this happened I got a replacement from Bambi. When that failed I found that it is a standard item. Machine Mart had them but I found one a lot cheaper on eBay.

[Howard LewisParticipant @howardlewis46836]

I had experience of a Bambi which seized, despite the oil level being OK. They do not seem to be intended to run on a high duty cycle. We wired the replacement into a timer circuit, so that it was only available for short set periods.

Is yours delivering air, satisfactorily?

This new one stopped delivering, and rattled. Cover off. A welsh washer, was no longer retained because the 1/4 UNF bolt had broken off, at the thread run out. Hard to remove the remains, but finally done. Made a guide "bung", drilled and tapped 1/2 UNF, and screwed in a stud with 1/2 UNF outer thread and 1/4 UNF internal thread at the outer end. Sealed welsh washer with Hylomar, topped up the oil (A colleague had tried running it the cover off – BAD move, but he won't rust! ) Compressor still performing happily some two years later.

Howard

[EmgeeParticipant @emgee]

Howard

Please explain what a welsh washer is used for, term I have never heard of.

Emgee

[Mike PooleParticipant @mikepoole82104]

Try welch washer.

Mike

[Neil WyattModerator @neilwyatt]

Or even welch plug…?

Neil

[davebParticipant @daveb17630]

Oil level is 1/2 way up the sight glass. After 10 minutes running the casing is much too hot to touch. Motor cuts off when pressure in tank reaches 100PSI. No noises except click when motor starts, very slight vibration when running. I haven't used it much, I bought it to use with my Bridgeport Spraymist coolant system, don't think it was running hot then. There is an external capacitor, I will replace it and see if matters improve.

Many thanks, help most appreciated.

Daveb

[Brian Sweeting 2Participant @briansweeting2]

Remember that these compressors are refrigerant compressors that are supposed to be cooled by the flow of refrigerant through them.

You should find somewhere in the instructions of your unit the recommended duty cycle. This should be designed to not overheat the motor by running too long and also not starting the motor more than a set number of times per hour.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Brian Sweeting on 26/09/2019 00:13:21:

Remember that these compressors are refrigerant compressors that are supposed to be cooled by the flow of refrigerant through them.

You should find somewhere in the instructions of your unit the recommended duty cycle. This should be designed to not overheat the motor by running too long and also not starting the motor more than a set number of times per hour.

.

What exactly do you mean by these compressors, Brian ?

MichaelG.

.

https://www.bambi-air.co.uk/

Edited By Michael Gilligan on 26/09/2019 07:02:32

[BOB BLACKSHAW 1Participant @bobblackshaw1]

I have a Jun Air the same type as the Bambi with similar problems.

I found CJS DIRECT COMPRESSERS 01213270395 Jeremy Foster very helpful, he sent me the manual for mine which is over 40 years old, I can strip it down and look for the problem.

Bob

[Chris GunnParticipant @chrisgunn36534]

The Bambi compressors are not all designed for continuous use, some were designed for applications where small amounts of air are needed intermittently. The manual states that the machine "can get quite hot in operation", and also "not to let the oil get hotter than 100 degrees c", which is also quite hot. I have a copy of the manual if anyone wants one, please send a pm.

Chris Gunn

[Brian Sweeting 2Participant @briansweeting2]

Posted by Michael Gilligan on 26/09/2019 07:02:03:

Posted by Brian Sweeting on 26/09/2019 00:13:21:

Remember that these compressors are refrigerant compressors that are supposed to be cooled by the flow of refrigerant through them.

You should find somewhere in the instructions of your unit the recommended duty cycle. This should be designed to not overheat the motor by running too long and also not starting the motor more than a set number of times per hour.

.

What exactly do you mean by these compressors, Brian ?

MichaelG.

.

**LINK**

Edited By Michael Gilligan on 26/09/2019 07:02:32

Sorry, should have added "hermetic" type.

[Howard LewisParticipant @howardlewis46836]

The Bambi that I dealt with was a reciprocating piston type, not a diaphragm type, hence the oil sight glass, mentioned.

They do seem to be low duty cycle machines.

A welsh or welch washer is a slightly convex disc, usually of steel. When placed in a recess, (shouldered hole ) only slightly larger in diameter than itself,, and pressed or hammered into place, it expands and seals.

The one on the Bambi had been clamped in place by a long 1/4 UNF bolt, which had broken at the thread run out.

Refrigerator compressors tend to run hot if the reed valves leak

Howard

[davebParticipant @daveb17630]

Bambi compressor BB24V

Thanks everyone. Capacitor seems OK, I fitted a new one, no difference. I previously used it with my Bridgeport Spraymist system, the air usage of which is fairly low. I noticed the compressor getting hot when I was blowing out some carburettor drillings which emptied the reservior two or three times, perhaps I'm expecting too much of it.

Daveb

[EmgeeParticipant @emgee]

Posted by Howard Lewis on 26/09/2019 21:54:00:

A welsh or welch washer is a slightly convex disc, usually of steel. When placed in a recess, (shouldered hole ) only slightly larger in diameter than itself,, and pressed or hammered into place, it expands and seals.

Howard

Thanks Howard, welch washer known to me as a "core plug", as used to blank off bores to water passages on IC engines blocks.

Emgee

[Howard LewisParticipant @howardlewis46836]

Yes, core plug was one of the uses to which they were put. At Rolls Royce, and on the early Perkins, engines screw in brass plugs were used. R-R sealed them with foul smelling Wellseal, as well as aluminium washers, which could only be removed from the skin with Trichlorethylene. (Try getting that today! ) Later they moved to Hylomar, which needed Methylene Chloride to shift it!

Later Perkins engines eventually used stainless steel cup plugs, which were sealed with a Loctite sealant.

The core plug that rusted through and leaked, was always the one at the back of the block, needing the engine out, or a hole cut in the firewall, to replace it.

Newton's Fourth law, the eternal cussedness of things; sometimes attributed to Sod!

Howard

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