Heating: Difference between revisions

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513 bytes removed ,  1 April 2013
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The wiring diagram inside the connection cover appears to show a capacitor-start motor with a centrifugal switch, but there is no obvious switch. It would be reasonable to assume some of the internal wiring is to a switch, but the connections shown are open circuit. Furthermore, if they were to a switch, it would turn the motor off once it got to speed.
The wiring diagram inside the connection cover appears to show a capacitor-start motor with a centrifugal switch, but there is no obvious switch. It would be reasonable to assume some of the internal wiring is to a switch, but the connections shown are open circuit. Furthermore, if they were to a switch, it would turn the motor off once it got to speed.


I'm guessing (maybe over-guessing) that there was previously a 3-phase motor installed and it has recently been replaced by this one, possibly bought from the engineer's mate website as part of surplus custom stock. It is thought to have worked for a while, and it isn't clear why it no longer works. Other documents on the TEC website show a different wiring for similar motor types, suggesting the wiring on this one may be unusual (perhaps it should have an external centrifugal switch?) or wrong. Or perhaps it shows a thermal cutout rather than a centrifugal switch, and that cutout has now blown ?
I'm guessing that it's not a centrifugal switch, but a thermal fuse. So the mains input is actually on Z2/U1 as shown on Tec's data sheet, but goes via V1/V2 to match the cover diagram. The fuse has blown for reasons unknown.




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Things we've checked :
Things we've checked :


Looking at the motor connections on the cover diagram, it's apparent that mains power must flow into V1 for any effect at all. But this connection has a high resistance to all other pins. It's either a burnt out winding, a faulty switch (unlikely, given the connections) or unused wiring (seems surprising, but there are too many wires for a simple single-phase capacitor-run motor).
Looking at the motor connections on the cover diagram, it's apparent that mains power must flow into V1 for any effect at all. But this connection has a high resistance to all other pins. It's either a burnt out winding, or possibly a thermal fuse.
 
The capacitor appears to be fine
The capacitor appears to be fine


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There is a [http://www.tecmotors.co.uk/sites/default/files/WIRING%20DIAGRAMS.pdf
There is a [http://www.tecmotors.co.uk/sites/default/files/WIRING%20DIAGRAMS.pdf
wiring diagram ]on the Tec website for capacitor-run motors which does not use the unconnected V1 pin. Perhaps this is the correct wiring ? But then how did the motor ever work ?
wiring diagram ] on the Tec website for capacitor-run motors which does not use the unconnected V1 pin. Perhaps this is the correct wiring ? But then how did the motor ever work ?