Contactors and relays

[Doc Hudson]

No it's not I understand now how it's done! I got confused with the bit when some one said 1.5mm to turn it on and then 25mm out! That's why I didn't think the cable for the 1.5 could handle such a current

It may be more polite if you draw out how you think things should be rather than expecting others to do all your work for you?

Doc H.

 

[Technician]

Relay selection can be a trying business. I saw a situation in which one fan had to start within a vital service if the other fan failed. All sorts of remedies were proposed and modifications abounded until some bright spark came up with the idea of current sensing relays. This was an excellent idea because it started the standby fan if the belts failed. At the time of the original construction, these relays were not, so far as I am aware, available.

Would someone now pick up the baton in this relay.

 

[m4tty]

Ok a very basic in laymans terms quick picture... ( I do hope this isnt your homework)http://i83.photobucket.com/albums/j293/gazjothomas/contactor023.jpg

Edit to say: the cable to A2 is 1.5mm

Scoobed for that diagram M cheers. Is the switching mcb always in the same board as the 3p mcb ? Cheers

 

[Sidewinder]

Not always M4tty, but either way you would need a dual supply warning for the enclosure.

You could feed the control from within the contactor enclosure even in 1.5 from even a 40A say circuit due to clauses in the regs, that way no notice, but you would have other considerations.

 

[M107]

I did consider drawing it that way sidey, but thought it would only confuse the already confused......if you know what I mean.

---------- Post Auto-Merged at 18:20 ---------- Previous post was made at 18:18 ----------

Thanks for the scoob Matty

 

[kme]

You could even use a relay with a 6 or 12V DC coil, and switch it on / off with bell wire and a couple of batteries - and if the relay (contactor) were to be large enough, you could interrupt thousands of Amps.

If you`re still stuck & unsure, Sandra can probably help - just "contact `er"