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+--- Thread: What size/type of circuit breaker do I need? (/showthread.php?tid=5791)
What size/type of circuit breaker do I need? - FiatFan - 01-25-2013
I'm planning to use this http://www.bakatronics.com/shop/item.aspx?itemid=581 motor control, this http://www.radioshack.com/product/index.jsp?productId=2102702&filterName=Type&filterValue=Transformers# transformer, and this http://www.radioshack.com/product/index.jsp?productId=2062583 rectifier to run a G scale engine. The manufacturer (USA Trains) confirmed in an e-mail to me that the engine requires 2.5 amps. The engine has two can-type motors.
I have about 145 feet of track in a single loop. No other engines/ track accessories will be run from this circuit. My question is what amperage any type of circuit breaker should I use and where in the circuit should I mount the breaker? If possible, I'd rather not use a fuse.
Any information, guidance, or suggestions will be greatly appreciated.
Tom
Re: What size/type of circuit breaker do I need? - Steamtrains - 01-25-2013
Seeing that your transformer is rated at 3A, you should use a circuit breaker rated at somewhat less, like 2.5A @ 120v, and put it on the input side of the transformer.
145 feet of track is quite a load. In order to avoid severe power drops, you should place your control in the center (+/-) of the loop and run several power feeds radially from it to the track.
Good luck..!!
Re: What size/type of circuit breaker do I need? - ezdays - 01-25-2013
Steamtrains Wrote:Seeing that your transformer is rated at 3A, you should use a circuit breaker rated at somewhat less, like 2.5A @ 120v, and put it on the input side of the transformer.
145 feet of track is quite a load. In order to avoid severe power drops, you should place your control in the center (+/-) of the loop and run several power feeds radially from it to the track.
Good luck..!!
That transformer's 3 Amp rating is for the secondary, the input will be around a tenth that at full load. I would recommend putting the breaker in the secondary circuit just to protect the transformer windings should there be a short on the load side. A 2.5A breaker will do, but I'd also try to calculate the load before selecting a value. The 2.5A would definitely protect the transformer regardless.
Re: What size/type of circuit breaker do I need? - faraway - 01-25-2013
You may use a medium or slow breaker if you have the choice between fast and slow breakers. A short overload peak (less than 500mS) would usually not do any harm to a transformer.
Re: What size/type of circuit breaker do I need? - BR60103 - 01-25-2013
The speed control says 2.5A, so I would go with that (if you can find one).
This should be put in one of the output lines from the controller -- last thing before the wires going to the track. Either side.
Another protection is a car tail-light bulb in series with the track. This gives you a visible indicator and you can sometimes even see how your current varies.
You could put 3A breaker before the controller, just in case.
Re: What size/type of circuit breaker do I need? - FiatFan - 01-26-2013
Thanks for your input everyone. I really appreciate it.
tom