Annoying Compressor fault....?

[the snooper]

Too prove it fill a cylinder with air and you will be able to rotate the flywheel by hand.. Now fill the same cylinder with H2O .. Water, you will not be able to turn the flywheel, and that's exactly the issue for the little compressors electric motor, trying to turn over whilst up against all that moisture ..

No chance what so ever, nonsense , with your theory, once the motor is upto speed the compression will be that great it's gonna do damage to the pump so we better not use compressors in the winter, also warm air can carry more moisture then cold air so on a hot humid summers day where does that leave your and @Mee 's theory

 

[the snooper]

My SIP's belt driven.

You've confused me now, is this post in response to roofman stating belt drives don't have temp problems ? If so you stated earlier that yours starts no matter what the ambient temp

 

[rtbcomp]

You've confused me now, is this post in response to roofman stating belt drives don't have temp problems ? If so you stated earlier that yours starts no matter what the ambient temp

My Clarke starts OK everytime, my SIP fails in winter. They're both 14 cfm, 3hp, belt driven, 240v single phase.

 

[brightspark]

My Clarke starts OK everytime, my SIP fails in winter. They're both 14 cfm, 3hp, belt driven, 240v single phase.

what speed are both motors 1450 or 2800 or both the same

 

[the snooper]

My Clarke starts OK everytime, my SIP fails in winter. They're both 14 cfm, 3hp, belt driven, 240v single phase.

oh yeah i see the problem now, i just never let the info you posted earlier sink in

 

[rtbcomp]

what speed are both motors 1450 or 2800 or both the same

The SIP says 2850, don't know about the Clarke.

 

[brightspark]

just wondered if one was faster running than the other I have one runs on 1450 the other 2800

 

[roofman]

this is a very strange problem with these integrals..ive had to completly empty tanks before today to stop it blowing fuses as it tried to start...perfect working unloader too

 

[the snooper]

this is a very strange problem with these integrals..ive had to completly empty tanks before today to stop it blowing fuses as it tried to start...perfect working unloader too

had one for tyres at work, just binned it, would never start in the cold. it was one of clarkes, a red one forget the model, on the other hand i also have a clarke tiger direct drive at home that i use when i only need a small amount of air and it starts flawlesly all the time

 

[rtbcomp]

just wondered if one was faster running than the other I have one runs on 1450 the other 2800

That should be taken care of with the pulleys, but the SIP sounds faster than the Clarke, even though it was advertised as "slow running" for reliabilty!

 

[brightspark]

the faster running one will require a higher starting torque to pull over than a slower running one

 

[roofman]

I come across the integs on a regular basis when mooching and rooting..i just keep walking

 

[normspanners]

this is a very strange problem with these integrals..ive had to completly empty tanks before today to stop it blowing fuses as it tried to start...perfect working unloader too

My theory on this is this, oil holds the motor back, the high speed motors have to accelerate more to reach sync, whilst fighting thick oil so sync is achieved easier on a slower speed motor, if sync isnt achieved quickly the volt amp scenario kicks in sooner having said that my comp is 1500 and still suffers till I change to winter oil.
Also no matter what, you will suffer a small amount of belt slip on a vee belt drive at start up which will help a little like slipping a clutch on a car to start off on a hill . Many of the belt drive compressors you will heard the belt squeal on start up as the motor fights to reach sync with normally tight belts, because the motor is producing maybe 4x rated HP for a second, whilst accelerating the flywheel and pump etc, but this slippage all helps with startup.

 

[roofman]

My theory on this is this, oil holds the motor back, the high speed motors have to accelerate more to reach sync, whilst fighting thick oil so sync is achieved easier on a slower speed motor, if sync isnt achieved quickly the volt amp scenario kicks in sooner having said that my comp is 1500 and still suffers till I change to winter oil.
Also no matter what, you will suffer a small amount of belt slip on a vee belt drive at start up which will help a little like slipping a clutch on a car to start off on a hill . Many of the belt drive compressors you will heard the belt squeal on start up as the motor fights to reach sync with normally tight belts, because the motor is producing maybe 4x rated HP for a second, whilst accelerating the flywheel and pump etc, but this slippage all helps with startup.

why do your posts always make sense

 

[the snooper]

why do your posts always make sense

he just copies and pastes from google


sorry Norm

 

[rtbcomp]

...
Also no matter what, you will suffer a small amount of belt slip on a vee belt drive at start up which will help a little like slipping a clutch on a car to start off on a hill . Many of the belt drive compressors you will heard the belt squeal on start up as the motor fights to reach sync with normally tight belts, because the motor is producing maybe 4x rated HP for a second, whilst accelerating the flywheel and pump etc, but this slippage all helps with startup.

Actually when the belt became slack on my Clarke it wouldn't start even on a warm day. As soon as the pump started pushing air into the tank the belt slipped and there wasn't enough momentum in the flywheel to carry the pump over TDC.

the faster running one will require a higher starting torque to pull over than a slower running one

Not convinced. True, the slower motor will generate 2x the torque of the faster one, but for a given pump it will have a 2x larger pulley, so the speed & torque delivered at the pump will be the same.

But would a pump designed to run with a faster motor have different bore/stroke than one driven by a slow motor? A larger bore would present more resistance (Pressure = Force/Area) requiring more torque, but then if the same delivery was achieved by a longer stroke the crank throw would be greater which gives more leverage against the flywheel which would require more torque. So to get the same air output and reduce the torque you need smaller bore & stroke and drive the pump faster. Personally I think it all comes out in the wash, ultimately the cfm & pressure depend on the motor hp.

Perhaps the problem is really down to cost and cutting corners, the equivalent Clarke to my SIP was £100 dearer and used the same pump as my SE16C150. Clarke do a cheaper version which looks more like my SIP - I wonder if that gives the same problems?

Maybe it's do with starting torque rather than running torque?

 

[eil]

Does the SIP have a PSC motor though .

 

[rtbcomp]

^^ It's electric

 

[eil]

Permanent split capacitor motor as opposed to a cap start-cap run motor, the cheaper compressors and the direct drive ones usually have the PSC motors, which means lower starting torque.

 

[rtbcomp]

I wouldn't know, looks like cap-start, cap-run. It certainly has 2 caps.