# Lionel KW transformer circuit breaker problems



## Blk69 (Feb 23, 2010)

I am having issues with my Lionel KW transformer. I got it out of my Dad's basement about 4 monts ago and it worked well with limited use (no more then 1/2 hr at full power, only one line powered). 

It sat outside my garage all summer (layout in garage). I moved the layout to the basement due to weather (getting cold). Transformer sat outside in cold weather for a few weeks. When I brought the Transformer into the basement worked fine for a few days that was about a week ago. Now after about 5 minutes use, it faults out. Fault will clear itself (red light will go out) and then fault again in about 10 sec when under load. Has to have a load connect for fault light to indicate. Condition is similar when running A and B circuits (only ran one at a time).

I believe the circuit breaker is my problem. This is a old unit and may have developed issues this summer. Is their a proper way to test for a failed circuit breaker? I can replace (Swap meet this weekend, hopefully parts vendors will be there) but would like to confirm diagnosis before swapping stuff out.


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## servoguy (Jul 10, 2010)

The only way to test the circuit breaker is to use a high current amp meter and variable resistor load to allow you to measure the current as you increase the load. This is not something that most people can do as they don't have the equipment. I have 4 KWs, and what they normally with a short is grunt until the circuit breaker opens. It is possible that you have something in your system that is drawing excess current. Do you have any other transformers you could use to test. For a single train, a 90 watt transformer like a 1033 should be plenty big enough.

The KW should supply about 7.5 amps before the internal breaker trips, and a train should not draw anywhere near this much. You could test things with a meter that has a 10 amp current range by putting the meter in SERIES with the transformer. Don't put the meter leads across the transformer. This would allow you to see how much current the train is taking. If it is drawing more than a 2-3 amps, something is going to get very hot. 

Bruce Baker


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## Blk69 (Feb 23, 2010)

I have a multimeter and a 90 W second transformer. I will test the current as you suggested. The load is a single engine Lionel F3 deseil with 4 MTH passenger cars (all lited). No accessorys. Don't believe would be drawings anywhere near 7 Amps.


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## gunrunnerjohn (Nov 10, 2010)

Just for grins, did you try the "B" side of the transformer? It probably won't make a difference, but it's something easy to test.


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