Looking for some help....Motor woes

[GraemeD]

I've been scoring all our local Freecycle boards for a toaster, so if anything comes up before I secure something from Ebay, it may yet become the solution! Sounds like I still need a contactor though.....it's the timer that the toaster circuit would replace.

I still reckon it is a great idea!

Graeme

 

[Digit]

I still reckon it is a great idea!

Everyone a gem!

Roy.

 

[9fingers]

My motor write up has now been revised as a result of this thread.

See Annex F

The link is in my signature below.

Bob

 

[OldWood]

Hi Bob
Good annex on the electronic switches. There does seem to be some problem with the wording in the 3rd last paragraph.

I did wonder initially why you hadn't gone down the route of talking about the reasons for the short start up time - ie smaller start up coil, etc., and the option of an external switch as Graeme was investigating, but realised that this approach has the hazard element of possibly over loading the starter winding as the thread discussed, and therefore is not really to be recommended.

It's interesting that the motor with electronic starting I worked on for my t/s was tatty when I recovered it from a skip; unfortunately I can't at the moment lay my hands on my notebook for 1999 to 2003 which by default must contain my records of the circuit, etc., but my guess would be that the motor must go back to the early 1990's. Memory says that there were two triacs - one to switch the system out and a second to discharge the starter capacitor so that, if switched on again, the starter cap. wouldn't face mains voltage on top of an existing charge. Can't remember quite how it came about but the purpose of this second triac was discovered empirically and resulted in a visit to the local rewinders for a replacement capacitor !!

Rob

 

[9fingers]

Hi Rob,

Thanks for pointing out the error - all fixed now.

I did not want to go down the route of speculating on the reasons why the 2 second limit might be imposed as it would be just that - speculation.

When Graeme spoke to ABB they did not offer the solution of increasing the time limit and whilst this may well work and can be implemented by someone who knows what they are doing and can accept the risks, I consider it unprofessional to have included it in my write up.

Bob