air compressor
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hi all , I have a little problem , got a air compressor(used) tried switching it on and it trips the rcd.
taken capacitor box off the motor tried switching it on again and "pop" a little puff of smoke comes out of the motor casing . any ideas what the problem might be .
thanks to any replys
taken capacitor box off the motor tried switching it on again and "pop" a little puff of smoke comes out of the motor casing . any ideas what the problem might be .
thanks to any replys
did you disconnect any cables before switching it back on ?
if it has a capacitor it single phase ie domestic 13A socket. A motor requires two different rotating magnetic fields to get the motor going - the capacitor acts to delay the current so that you have two rotating magetic fields which work to get the motor spinning. No 2nd field no rotation and the motor will draw a lot of power hence the puff of smoke. the rcd tripping would indicate that you had a leak of power to earth causing it to trip.
You need to check the coils and also check the condition of the coils. These motors normally have a centrifugal switch that disconnects the start capacitor when the motor is up and running.
check your coils and also do an insulation check to see what was causing the rcd to trip.
if it has a capacitor it single phase ie domestic 13A socket. A motor requires two different rotating magnetic fields to get the motor going - the capacitor acts to delay the current so that you have two rotating magetic fields which work to get the motor spinning. No 2nd field no rotation and the motor will draw a lot of power hence the puff of smoke. the rcd tripping would indicate that you had a leak of power to earth causing it to trip.
You need to check the coils and also check the condition of the coils. These motors normally have a centrifugal switch that disconnects the start capacitor when the motor is up and running.
check your coils and also do an insulation check to see what was causing the rcd to trip.
ruggedscotty said:
did you disconnect any cables before switching it back on ?
if it has a capacitor it single phase ie domestic 13A socket. A motor requires two different rotating magnetic fields to get the motor going - the capacitor acts to delay the current so that you have two rotating magetic fields which work to get the motor spinning. No 2nd field no rotation and the motor will draw a lot of power hence the puff of smoke. the rcd tripping would indicate that you had a leak of power to earth causing it to trip.
You need to check the coils and also check the condition of the coils. These motors normally have a centrifugal switch that disconnects the start capacitor when the motor is up and running.
check your coils and also do an insulation check to see what was causing the rcd to trip.
And this is why Pistonheads will always be the greatest forum 'in the worrld..' if it has a capacitor it single phase ie domestic 13A socket. A motor requires two different rotating magnetic fields to get the motor going - the capacitor acts to delay the current so that you have two rotating magetic fields which work to get the motor spinning. No 2nd field no rotation and the motor will draw a lot of power hence the puff of smoke. the rcd tripping would indicate that you had a leak of power to earth causing it to trip.
You need to check the coils and also check the condition of the coils. These motors normally have a centrifugal switch that disconnects the start capacitor when the motor is up and running.
check your coils and also do an insulation check to see what was causing the rcd to trip.
Age of capacitors - where the motor has been stored - if ts been used has the supply been prone to surges etc - lots of things can cause fails. running the motor overloaded - the mechanical part of the compressor how is that ? lubrication ? its hard to diagnose with out having a good route about it.
Id have a good check over all the connections. and as said check the motor windings
above shows a schematic of a twin capacitor motor - two windings a main and a second winding its the two windings acting on the rotor that generates the rotation. The rotor actually has conductive circuits within it that when placed in the rotating magnetic field induce currents in the rotor that react with the rotating field. The start capacitor is set up to provide more umph to get the motor rotating. Once rotating fast enough the centrifugal switch disconnects the start capacitor and the run capacitor provides the required phase shift in the magnetic fields to keep the rotor spinning. If the rotor slows it draws more power if the rotor stops or stalls it draws a lot more power. remember electric motors can produce a lot of torque at zero revs. no start / run winding then it will draw a lot of power an as it doesnt start to rotate it will keep drawing power.
Id warn you that these capacitors can and will bite - they can store electricity enough of it to really give you a bad jolt. So be careful when working on them. Its not the first time someone has unplugged the power and then picked themselves off of the floor after completing the circuit through themselves.
Id have a good check over all the connections. and as said check the motor windings
above shows a schematic of a twin capacitor motor - two windings a main and a second winding its the two windings acting on the rotor that generates the rotation. The rotor actually has conductive circuits within it that when placed in the rotating magnetic field induce currents in the rotor that react with the rotating field. The start capacitor is set up to provide more umph to get the motor rotating. Once rotating fast enough the centrifugal switch disconnects the start capacitor and the run capacitor provides the required phase shift in the magnetic fields to keep the rotor spinning. If the rotor slows it draws more power if the rotor stops or stalls it draws a lot more power. remember electric motors can produce a lot of torque at zero revs. no start / run winding then it will draw a lot of power an as it doesnt start to rotate it will keep drawing power.
Id warn you that these capacitors can and will bite - they can store electricity enough of it to really give you a bad jolt. So be careful when working on them. Its not the first time someone has unplugged the power and then picked themselves off of the floor after completing the circuit through themselves.
Capacitors are really quite nasty things. Best to get a resistor to deliberately short across the capacitors to drain them in a controlled manner before you work on the electrics. ruggedscotty said:
Age of capacitors - where the motor has been stored - if ts been used has the supply been prone to surges etc - lots of things can cause fails. running the motor overloaded - the mechanical part of the compressor how is that ? lubrication ? its hard to diagnose with out having a good route about it.
Id have a good check over all the connections. and as said check the motor windings
above shows a schematic of a twin capacitor motor - two windings a main and a second winding its the two windings acting on the rotor that generates the rotation. The rotor actually has conductive circuits within it that when placed in the rotating magnetic field induce currents in the rotor that react with the rotating field. The start capacitor is set up to provide more umph to get the motor rotating. Once rotating fast enough the centrifugal switch disconnects the start capacitor and the run capacitor provides the required phase shift in the magnetic fields to keep the rotor spinning. If the rotor slows it draws more power if the rotor stops or stalls it draws a lot more power. remember electric motors can produce a lot of torque at zero revs. no start / run winding then it will draw a lot of power an as it doesnt start to rotate it will keep drawing power.
Id warn you that these capacitors can and will bite - they can store electricity enough of it to really give you a bad jolt. So be careful when working on them. Its not the first time someone has unplugged the power and then picked themselves off of the floor after completing the circuit through themselves.
thanks for all your help I have tried getting in contact with a certain black compressor maker and I have Id have a good check over all the connections. and as said check the motor windings
above shows a schematic of a twin capacitor motor - two windings a main and a second winding its the two windings acting on the rotor that generates the rotation. The rotor actually has conductive circuits within it that when placed in the rotating magnetic field induce currents in the rotor that react with the rotating field. The start capacitor is set up to provide more umph to get the motor rotating. Once rotating fast enough the centrifugal switch disconnects the start capacitor and the run capacitor provides the required phase shift in the magnetic fields to keep the rotor spinning. If the rotor slows it draws more power if the rotor stops or stalls it draws a lot more power. remember electric motors can produce a lot of torque at zero revs. no start / run winding then it will draw a lot of power an as it doesnt start to rotate it will keep drawing power.
Id warn you that these capacitors can and will bite - they can store electricity enough of it to really give you a bad jolt. So be careful when working on them. Its not the first time someone has unplugged the power and then picked themselves off of the floor after completing the circuit through themselves.
got a little bit of help, any idea where PIS compressors are made ? I know its Italy but have not been able to get any information about them .
the compressor is only about 2 years old , hardly done much , the sellers PIS UK , have told me I have a compressor that's not big enough for work I do with it . TN3 150 LITRE TANK , I only do touch ups spray wise and they are trying to flog me a bigger pressor , are they taking the SIP or what .
kambites said:
Daft quesiton perhaps but is it actually an RCB that's tripping, as opposed to an RCBO or MCB?
it trips the house circuit breaker , mains socket breaker switch nothing else one thing I was thinking :- if the power is tripped immediately is there any power reaching the capacitors (start one and a run capacitor)?
if I were to power the capacitors would that make any difference ? .
Edited by doglover3 on Friday 10th April 18:39
Edited by doglover3 on Friday 10th April 20:21
You have a MCB protecting the ring and a main circuit breaker. The main circuit breaker usually has an RCD incorporated.
This is how it works - The RCD is a residual circuit breaker this means that it monitors the electricity flow into and out of the circuit. If these values differ by more than 30mA or 0.03A it picks this up and trips the device. This is to protect against 'leakage' of electricity. This is usually an uncontrolled leak from the circuit to earth. And such leaks come through faulty components or even an inadvertant contact with a live wire. This is quite something to grasp. Why does electricity flow to earth ?
simple terms the electricity company distributes power at high voltage - this is stepped down near to the customer by a transformer usually in three phase format. This means that you have three live wires each wire 240 volts or there abouts to neutral. of course between the live wires you have 415 volts. The neutral wire is grounded at the transformer. This giving you a ground. So you have five cables now L1 L2 L3 Neutral and Earth. Into each residential house you have three wires one of the L1 L2 L3 wires a neutral and an earth wire.
The supply passes through the main circuit breaker and then through your ring main circuit breaker. The main circuit beaker having a residual current function coupled with the over current function of the individual circuit breaker.
I dont understand what you said about powering up the capacitor - you cant do that - the capacitors need to be in circuit with the coils. Putting power across the capacitor itself wont achieve anything. The capacitor wont charge as you are on an alternating current.
The current changes direction 50 times a second. Its this that gives you the rotational field. The capacitors providing two rotational fields that make the rotor spin.
The fact that you have two circuit breakers tripping indicates an excessive inrush current or overload along with an earth leakage fault. you could try to isolate the fault and see what is happening. As a purely investigative step you could place the compressor on a non conductive sheet of plastic disconnect the earth connection at the plug and then see if it powers up without tripping the circuit breaker.
Be aware if operating without the earth connected do not touch the compressor - do not operate it like that for any length of time as you are only proving what or where the fault is. if no trip then there is an earth fault that needs to be identified.
This is how it works - The RCD is a residual circuit breaker this means that it monitors the electricity flow into and out of the circuit. If these values differ by more than 30mA or 0.03A it picks this up and trips the device. This is to protect against 'leakage' of electricity. This is usually an uncontrolled leak from the circuit to earth. And such leaks come through faulty components or even an inadvertant contact with a live wire. This is quite something to grasp. Why does electricity flow to earth ?
simple terms the electricity company distributes power at high voltage - this is stepped down near to the customer by a transformer usually in three phase format. This means that you have three live wires each wire 240 volts or there abouts to neutral. of course between the live wires you have 415 volts. The neutral wire is grounded at the transformer. This giving you a ground. So you have five cables now L1 L2 L3 Neutral and Earth. Into each residential house you have three wires one of the L1 L2 L3 wires a neutral and an earth wire.
The supply passes through the main circuit breaker and then through your ring main circuit breaker. The main circuit beaker having a residual current function coupled with the over current function of the individual circuit breaker.
I dont understand what you said about powering up the capacitor - you cant do that - the capacitors need to be in circuit with the coils. Putting power across the capacitor itself wont achieve anything. The capacitor wont charge as you are on an alternating current.
The current changes direction 50 times a second. Its this that gives you the rotational field. The capacitors providing two rotational fields that make the rotor spin.
The fact that you have two circuit breakers tripping indicates an excessive inrush current or overload along with an earth leakage fault. you could try to isolate the fault and see what is happening. As a purely investigative step you could place the compressor on a non conductive sheet of plastic disconnect the earth connection at the plug and then see if it powers up without tripping the circuit breaker.
Be aware if operating without the earth connected do not touch the compressor - do not operate it like that for any length of time as you are only proving what or where the fault is. if no trip then there is an earth fault that needs to be identified.
ruggedscotty said:
You have a MCB protecting the ring and a main circuit breaker. The main circuit breaker usually has an RCD incorporated.
This is how it works - The RCD is a residual circuit breaker this means that it monitors the electricity flow into and out of the circuit. If these values differ by more than 30mA or 0.03A it picks this up and trips the device. This is to protect against 'leakage' of electricity. This is usually an uncontrolled leak from the circuit to earth. And such leaks come through faulty components or even an inadvertant contact with a live wire. This is quite something to grasp. Why does electricity flow to earth ?
simple terms the electricity company distributes power at high voltage - this is stepped down near to the customer by a transformer usually in three phase format. This means that you have three live wires each wire 240 volts or there abouts to neutral. of course between the live wires you have 415 volts. The neutral wire is grounded at the transformer. This giving you a ground. So you have five cables now L1 L2 L3 Neutral and Earth. Into each residential house you have three wires one of the L1 L2 L3 wires a neutral and an earth wire.
The supply passes through the main circuit breaker and then through your ring main circuit breaker. The main circuit beaker having a residual current function coupled with the over current function of the individual circuit breaker.
I dont understand what you said about powering up the capacitor - you cant do that - the capacitors need to be in circuit with the coils. Putting power across the capacitor itself wont achieve anything. The capacitor wont charge as you are on an alternating current.
The current changes direction 50 times a second. Its this that gives you the rotational field. The capacitors providing two rotational fields that make the rotor spin.
The fact that you have two circuit breakers tripping indicates an excessive inrush current or overload along with an earth leakage fault. you could try to isolate the fault and see what is happening. As a purely investigative step you could place the compressor on a non conductive sheet of plastic disconnect the earth connection at the plug and then see if it powers up without tripping the circuit breaker.
Be aware if operating without the earth connected do not touch the compressor - do not operate it like that for any length of time as you are only proving what or where the fault is. if no trip then there is an earth fault that needs to be identified.
the earth trick sounds good because that is right where the puff of smoke comes from, where the earth cable is screwed into the motor housing there is another hole next to the earth fixing . This is how it works - The RCD is a residual circuit breaker this means that it monitors the electricity flow into and out of the circuit. If these values differ by more than 30mA or 0.03A it picks this up and trips the device. This is to protect against 'leakage' of electricity. This is usually an uncontrolled leak from the circuit to earth. And such leaks come through faulty components or even an inadvertant contact with a live wire. This is quite something to grasp. Why does electricity flow to earth ?
simple terms the electricity company distributes power at high voltage - this is stepped down near to the customer by a transformer usually in three phase format. This means that you have three live wires each wire 240 volts or there abouts to neutral. of course between the live wires you have 415 volts. The neutral wire is grounded at the transformer. This giving you a ground. So you have five cables now L1 L2 L3 Neutral and Earth. Into each residential house you have three wires one of the L1 L2 L3 wires a neutral and an earth wire.
The supply passes through the main circuit breaker and then through your ring main circuit breaker. The main circuit beaker having a residual current function coupled with the over current function of the individual circuit breaker.
I dont understand what you said about powering up the capacitor - you cant do that - the capacitors need to be in circuit with the coils. Putting power across the capacitor itself wont achieve anything. The capacitor wont charge as you are on an alternating current.
The current changes direction 50 times a second. Its this that gives you the rotational field. The capacitors providing two rotational fields that make the rotor spin.
The fact that you have two circuit breakers tripping indicates an excessive inrush current or overload along with an earth leakage fault. you could try to isolate the fault and see what is happening. As a purely investigative step you could place the compressor on a non conductive sheet of plastic disconnect the earth connection at the plug and then see if it powers up without tripping the circuit breaker.
Be aware if operating without the earth connected do not touch the compressor - do not operate it like that for any length of time as you are only proving what or where the fault is. if no trip then there is an earth fault that needs to be identified.
only trouble is the plug is a nice newish rubber moulded one and I don't want to mess it up , but I will give it a go . cheers again
king about with it?So its a molded plug..... how to disconnect the earth ? use a made up plug and socket that would give you the option to disconnect the earth - just for a test.
Id also be more inclined to let someone who knows about these things to have a look. The mains is a dangerous thing bud. and as for capacitors these can be evil Ive seen ones where the discharge resistor has failed and they sit there with a couple of hundred volts on them just waiting for the unwary.
If you bought it what about taking it back to where you got it and asking them for some help.....
The little puff of smoke probably came from the winding - a loose connection probably wouldnt give a puff of smoke.
Id also be more inclined to let someone who knows about these things to have a look. The mains is a dangerous thing bud. and as for capacitors these can be evil Ive seen ones where the discharge resistor has failed and they sit there with a couple of hundred volts on them just waiting for the unwary.
If you bought it what about taking it back to where you got it and asking them for some help.....
The little puff of smoke probably came from the winding - a loose connection probably wouldnt give a puff of smoke.
just had a bit more of a look and noticed the spade connectors from (not on) the run capacitor are a lot more bronze in colour compared to the start leads . even the end connected to the reset switch is darker in colour also . could it be anything to do with the reset switch , it feels loose and does not click .
I work for a compressor company
First thing we do when a compressor fails to start is take the belts off
Then check to see if the motor turns by hand and if the pump unit does the same
A seized pump unit can often blow a motor as well
IF its just the motor take to some one who knows what they are doing
IME compressors this size are often stupidly expensive to fix compared to replacing it
(no we don't offer compressors that small, try ebay, machine mart of screwfix)
First thing we do when a compressor fails to start is take the belts off
Then check to see if the motor turns by hand and if the pump unit does the same
A seized pump unit can often blow a motor as well
IF its just the motor take to some one who knows what they are doing
IME compressors this size are often stupidly expensive to fix compared to replacing it
(no we don't offer compressors that small, try ebay, machine mart of screwfix)
you would have to check the continuity of the switch - if its ok and not tripped then it wont click when you push it as its already in - also it may feel a little lose as the switch is engaged and not sprung back against the reset button.
as for the coloured spade connectors these can be so depending on what metal has been used to make em.
try get some photos up if you can and that may help
as for the coloured spade connectors these can be so depending on what metal has been used to make em.
try get some photos up if you can and that may help
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