Circuit breaker

[Brett]

I have a C type 20amp 3 phase circuit breaker at work.

I have a PT 185 and it trips it all the time .

Can anyone with a similar machine tell me what size fuse you use?

[MAC702]

Don't you have your owner's manual? Doesn't it say what breaker (not fuse) to use? Or is it tripping the recommended breaker size? This is a Lincoln, right?

[RubenZ]

20amps breaker too small. Try 30 or 40. When does it trip? after a certain amp setting ?

[MAC702]

I just read YOUR owner's manual, downloaded from www.lincolnelectric.com. Since you mention 3-phase breaker, can we assume you are operating it with 208V input? In which case, at RATED output, it will draw 35A, and more when maxed out.

How big are the wires from your breaker to your receptacle? What kind (NEMA config.) of receptacle/plug are you using?

[Brett]

I just read YOUR owner's manual, downloaded from www.lincolnelectric.com. Since you mention 3-phase breaker, can we assume you are operating it with 208V input? In which case, at RATED output, it will draw 35A, and more when maxed out.

How big are the wires from your breaker to your receptacle? What kind (NEMA config.) of receptacle/plug are you using?

Im in Australia its 415V

Owners manual at work, Im at home at the moment (its 10.17am Sunday here)

Didnt know you could down load manual thanks, I'll have a look.

Not sure of mm^2 of wires .

[Brett]

20amps breaker too small. Try 30 or 40. When does it trip? after a certain amp setting ?


Not sure when it trips I usually just set it to 160 or so and roll on with a hand amp controller (its all aluminium work)

[MAC702]

Im in Australia its 415VWell, now, that changes everything. 20A of 415V would provide the same power (pretty much) as a 40A of 208V. The manual I D.L.'ed doesn't cover that voltage input model. But you may be able to provide your serial number and get the proper manual for your Australian model. Let us know what you find.

[Brett]

Yes, I thought 20A on 415V should have been enough.

Does any one know the difference between a D type "breaker (not fuse:) ) and a C type ?

Cant seem to find manual will have another look

Thanks for the replies

[stumpster]

I'm no electrician (so maybe I should keep my mouth shut) but I thought the types just indicate the style panel they go with, the way they mount in.

I said "maybe":)

[awright]

The class has to do with the time delay characteristics of the breaker, that is, how fast the circuit will be opened for various degrees of overcurrent.

Check out IEE regulations such as: http://www.tlc-direct.co.uk/Book/3.6.4.htm
A "D" type breaker is described in the cited document as being appropriate for circuits with high inrush current, such as transformers and welding machines.

A breaker with a relatively long delay is appropriate for motor circuits due to the very high currents drawn by a motor during startup. Shorter delays are appropriate for circuits that do not normally draw significant overloads but which may be subjected to abrupt, rapidly increasing fault currents.

The best way to select the proper breaker is to refer to the operator's manual and follow the guidelines presented therein for breaker rating and type.

awright