the snooper
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im assuming that the sealey is a direct drive machine
my belt drive works fine but the direct drive doesnt
- Thread starter alfapat
- Start date
im assuming that the sealey is a direct drive machine
my belt drive works fine but the direct drive doesnt
the snooper
getting older by the day
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it could be down to what viscosity oil is in it
transits dont like 10/40 oil in winter when its very cold but put 5/30 in them and they start no problems
worth an oil change i suppose
transits dont like 10/40 oil in winter when its very cold but put 5/30 in them and they start no problems
worth an oil change i suppose
Alfapat, have a check of your supply. Maybe drag the compressor in to the house and plug it in there to see if it's any better. It can be a difficult problem to diagnose and will often appear to be a capacitor fault or valve problem but a too long or too thin cable supplying the socket you have the compressor plugged in to can cause a big voltage drop. Voltage drop is proportional to current so when the compressor motor starts it's extra large current draw means a big volt drop so it struggles to get the speed up and after a few seconds it trips. Or, when the tank's nearly full and the load is increased, so is the current draw, the same thing happens.
SAE 20 compressor oil, it's what I use in all my piston compressors.
I'm convinced that oil won't be the problem in this case. If a piston pump is turned manually there is very little resistance, even when really cold. If the motor can't overcome the start effort or trips the breaker in the attempt it will be an electrical problem.
the snooper
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i think the breaker he refers to is the overload cut out not the actual circuit breaker
it hard to diagnose over the internet but here's a couple more questions anyway:
is the fuse box supplying the compressor in an outbuilding and if so, what size and how long is the cable supplying that fusebox from the meter?
does the motor start slowly and struggle to get to speed before it trips the breaker or is it running and sounding normal when it trips?
as someone above said, disconnect the pipe from the head(s) and if it starts up fine then you have a pneumatic problem, if it still runs badly, it's the motor or electrical side of things.
secondly, just to be clear, is it direct drive or belt, is it cap start or cap start and run?
is the fuse box supplying the compressor in an outbuilding and if so, what size and how long is the cable supplying that fusebox from the meter?
does the motor start slowly and struggle to get to speed before it trips the breaker or is it running and sounding normal when it trips?
as someone above said, disconnect the pipe from the head(s) and if it starts up fine then you have a pneumatic problem, if it still runs badly, it's the motor or electrical side of things.
secondly, just to be clear, is it direct drive or belt, is it cap start or cap start and run?
the snooper
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all i can say is google compressor oil cold weather
there is loads of info from people with the same problem he does state its fine in summer its a common problem
there is loads of info from people with the same problem he does state its fine in summer its a common problem
All I can say is that having turned quite a few compressor pumps by hand, even when at low temperatures, it takes very little effort. So if a motor struggles to provide that effort it must be faulty. I repaired a belt drive recently with a failed non return valve, so it was restarting against receiver pressure. The motor pulley actually spun in the belt for a few seconds until the pump got upto speed, so the motor had more than enough power to overcome the resistance. I realise there is a gearing advantage on a belt drive unit but even so, a small direct drive pump will be even easier to turn at start up.
I'll be very surprised if it's not a fault on the motor causing the problem in this case.
I'll be very surprised if it's not a fault on the motor causing the problem in this case.
I have the Sealey 3hp 50ltr d/drive,Had it about 4 years now and In the winter the colder it gets the more it struggles to start.I have a very thick armored cable going from the garage to the fuse box about 50 feet away........PS i just won another one identical to mine from a car mag competition,So will couple the 2 compressors together.
Ok guys , first of all I will check the voltage when I get a chance, then undo the pipe and try the puematic check, I know I can restart fine if the tank is drained.
As it was suggested the motor struggles when asked to cut in and replenish the tank, it can do it if if its warm , but even after half an hour last night it tripped the overload.
I will get back to you when I get more info.
Many thanks in the meantime , much appreciated from all of you.
As it was suggested the motor struggles when asked to cut in and replenish the tank, it can do it if if its warm , but even after half an hour last night it tripped the overload.
I will get back to you when I get more info.
Many thanks in the meantime , much appreciated from all of you.
Not exactly , only started this on really cold nights .I think this is coincedental with whats going wrong , but could be wrong.
By the way its belt drive. 150 LITRE 2.2 KW MOTOR 3HP SINGLE PHASE .
Have you done any mechanical checks ? Like trying to turn it by hand, with the power isolated of course ! It should turn easily if the unloader valve has done it's job.
A friend had a belt drive unit that struggled in the cold and eventually I convinced him to try the above and the motor was found to be as stiff as hell to turn ! It was the bearings.
How does it sound when it starts up before it trips ? Does it sound like it's struggling ?
A friend had a belt drive unit that struggled in the cold and eventually I convinced him to try the above and the motor was found to be as stiff as hell to turn ! It was the bearings.
How does it sound when it starts up before it trips ? Does it sound like it's struggling ?
the snooper
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just been in garage to spray a mirror temp is 2 or 3 degrees here compressor wouldnt start without a little warmth its a belt drive 3hp
and it usually works fine
and it usually works fine
roofman
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I'm beginning to think that the problems that many are having with compressors that are sluggish to start in low temperatures, could be due to capacitors that have reduced in value but not yet failed completely. So the start torque of the motor is reduced.
Caps have a finite life, especially in this application. There are two basic types of single phase capacitor start motor. 1/ cap to start and cap to run, the start cap just provides the initial phase shift to increase start torque, it is then switched out by a relay or centrifugal switch and the motor continues to run with the run cap permanently in circuit during normal running. 2/ Permanent split capacitor motor, where one cap starts and runs the motor. Obviously, the motor having 1 or 2 caps identifies which it is.
In either case a defective cap will cause problems but the permanent split cap type motor will probably just completely fail to start if the cap is defective or has failed.
I'm still convinced that unless there is a mechanical defect with either the compressor pump or motor that a compressor should start irrespective of how low the temperature is, unless it's Siberian conditions !
Every pump or motor in normal working condition that I've turned manually by hand required very little force to do so. Therefore a 2 or 3 hp motor in proper working conditon should have no problem starting up. Even my V Twin Ingersoll Rand T30 is a doddle to turn by hand.
I reckon there are alot of caps out there are on the way out and responsible for this problem. Word of advice to the wise, when replacing caps, use genuinely British or European made ones, any from the far east are to be suspected full stop. If they haven't failed already they will not give anywhere near the life of quality types.
Also, in general, older caps, like over 20 years old or even older, still seem to work even now. It's the ones of newer, non oil-filled type that have a relatively limited life. We have the environmentalists to blame for that !
Caps have a finite life, especially in this application. There are two basic types of single phase capacitor start motor. 1/ cap to start and cap to run, the start cap just provides the initial phase shift to increase start torque, it is then switched out by a relay or centrifugal switch and the motor continues to run with the run cap permanently in circuit during normal running. 2/ Permanent split capacitor motor, where one cap starts and runs the motor. Obviously, the motor having 1 or 2 caps identifies which it is.
In either case a defective cap will cause problems but the permanent split cap type motor will probably just completely fail to start if the cap is defective or has failed.
I'm still convinced that unless there is a mechanical defect with either the compressor pump or motor that a compressor should start irrespective of how low the temperature is, unless it's Siberian conditions !
Every pump or motor in normal working condition that I've turned manually by hand required very little force to do so. Therefore a 2 or 3 hp motor in proper working conditon should have no problem starting up. Even my V Twin Ingersoll Rand T30 is a doddle to turn by hand.
I reckon there are alot of caps out there are on the way out and responsible for this problem. Word of advice to the wise, when replacing caps, use genuinely British or European made ones, any from the far east are to be suspected full stop. If they haven't failed already they will not give anywhere near the life of quality types.
Also, in general, older caps, like over 20 years old or even older, still seem to work even now. It's the ones of newer, non oil-filled type that have a relatively limited life. We have the environmentalists to blame for that !
brightspark
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its well noticable when its cold that the starting load is greater i had a 90cfm v twin pump coupled to a 20hp lister diesel engine in reasonable weather it would crank over no problem 
but when cold it wouldnt . allso have an old 3 hp brooks motor on a 14cfm comp that ive used for 35 years when verry cold i can notice a slower start and a good dip in the lights there bound to take more power when cold . i might conduct a test . take the starting current readings when its not freezing then il take another when it is freezing . i also have a dual motor comp. one old motor and a new one on it il take the readings of it allso over the next few weeks if it freezes hard and post results 
but when cold it wouldnt . allso have an old 3 hp brooks motor on a 14cfm comp that ive used for 35 years when verry cold i can notice a slower start and a good dip in the lights there bound to take more power when cold . i might conduct a test . take the starting current readings when its not freezing then il take another when it is freezing . i also have a dual motor comp. one old motor and a new one on it il take the readings of it allso over the next few weeks if it freezes hard and post results I would expect there to be more load when cold but not so much as to prevent the appropriate size motor from starting. My experience seems to be in conflict to that of many others though. Ran my 3.5 HP belt drive yesterday after standing idle for a few days and it started with no noticable difference to that in summer ! It was about 3 degrees in the place it's kept. Going to try my little 1.5 HP direct on Monday, that hasn't been used for a while.
