The red light on a ZW or Z type transformer takes a lot of time to come on, about five seconds or better, usually something on the track will get hot if the red light comes on and stays on. You can usually tell when you have a short by the power being lost to the other outputs because as Bob N. mentioned the circuit breaker is on the U terminal side, or there is only one circuit breaker for the whole transformer.
I don't know what the 91 circuit breakers are rated at, Greenberg's price guide just gives the years it was made and what it could bring when sold.
Lee F.
If I have built in circuit breakers in my Z transformers, I do not need any 91 circuit breakers, correct?? The Z's have a red light for a circuit breaker, if it were to be tripped the red light would go on. Same idea as the 91. Thanks.
Does the 91 with 2 terminal posts hook up the same way as the one with 3 terminal posts?? On my 91 with 3 posts, I only use the A and Low posts. The 91 with 2 posts, it would hook up the same way, using both bottom posts, just like the 91 with 3 posts?? Thanks.
So, you think it would be okay to use a 91 with my standard gauge trains? The locomotives that I use are the 33, 10E, 380E, 384E, 385E, and 392E. I have 3 electrics and 3 steams. I hooked up the 91 with my cheaper 10E and it worked just fine, did not trip. It did trip when I put the wheels on the middle rail, just to test to see if the light works and that it did trip and cut power. All worked just fine. I have 5 Z transformers running all my standard trains. Also, I use 5 of the 167's for whistle and direction control. I hope this info helps. I am not sure if all the built in breakers on my Z's all work just fine. I have never had the breakers tripped on all my Z's. I hope they all function just fine. I do not wanna try and test to see if they work, too dangerous and could damage my Z's. My standard trains stay on the track pretty good. Thanks.
Because the Z has its single 15-ampere circuit breaker in series with its common, it can be made significantly safer by adding circuit breakers in series with whichever of the outputs (A, B, C, or D) you are using. Those additional breakers should be rated at no more than 15 amperes. However, if you use breakers with lower ratings, you can safely use wire smaller than 14 AWG, specifically 16 AWG with a 10-ampere breaker and 20 AWG with a 5-ampere breaker.
You should not depend on circuit breakers to protect electronics. They are for protecting wiring and your transformer. Use transient-voltage suppressors to protect electronics (if any). Once an electronics-intensive locomotive begins to draw enough current to trip a circuit breaker, however slow or fast, it is already damaged. Slow (thermal) circuit breakers (like the 91) have the advantage that they do not trip on momentary overloads.
The problem I would have with the 91 is that we don't know what its rating is. Maybe someone else on the forum does.
Bob Nelson
I am talking about the Postwar Lionel Z transformer that is 250 Watts. I do not have any high end electronics. All my trains are prewar or postwar Lionel. I hope this info helps. Thanks.
The number 91 circuit breaker was for use with either pre war or post war trains and won't give you any benefit for todays high tech electronics in the trains.
Which Z transformer are you talking about? The post war Z by Lionel or the modern Z series by MTH? If it is the modern Z-750 or Z-1000 by MTH the 91 circuit breaker won't give any added protection, the new transformers have a built-in fast acting circuit breaker.
On my layout I am using 10 amp circuit breakers hooked up to the output terminals, A to D, on my post war ZW. The circuit breakers that I have I purchased from Scott's Odds and Ends. Circuit breakers are always wired in series from the source to the load.
Can the 91 circuit breaker be used with a Z transformer? You can only use (1) 91 per loop of track, correct? My 91 has 3 terminals and works just fine. Would it hurt my Z transformer if I was to hook it up to it? I mean my Z's all have built in Circuit breakers, but could I use the 91 for extra precautions? Just so it wont trip on the Z and will trip on the 91 instead and cut power to the Z. Also, can the 91 be wired to a 66 whistle controller? And they all must be wired in series, correct? Thanks.
Our community is FREE to join. To participate you must either login or register for an account.
Get the Classic Toy Trains newsletter delivered to your inbox twice a month