The Lionel 92 circuit breaker provides an important safety feature. Additionally, if you use a low-end transformer that lacks a direction button, it provides a handy direction button. Unfortunately the original Lionel 92 circuit breaker instructions have one mistake in them.
Here’s how to use this critical accessory to maximize your personal safety. Depending on your setup, you may need more than one of them.
Setup between the transformer and track
The Lionel 92 circuit breaker has two binding posts on it. Connect the hot terminal of your transformer to one post, then connect the other post to the center rail of your track, which is clip #1 on your lockon. On small Lionel transformers with only two posts, the hot post is usually the one on the left.
On medium-sized transformers like the 1033, the hot post is usually post A. One notable exception is the LW, which uses post U. Large transformers like the KW and ZW use post A for hot. If I haven’t mentioned your transformer specifically, see my pinouts for Lionel transformers.
Lionel makes no mention of other makes of transformers, but their circuit breaker works fine with them.
On small Marx transformers, the hot post is the one on the right, the opposite of small Lionel transformers. On medium-sized Marx transformers with both train and accessory outputs, the hot post is the lower post.
On American Flyer transformers, your hot post is the one not marked “base post.”
It’s critical that you not connect the circuit breaker to the common post, because in a multi-transformer setup, it’s possible for some voltage to linger and defeat the circuit breaker.
Many transformers have built-in circuit breakers, but these can malfunction over time. If the circuit breaker doesn’t trip after shorting the terminals for 12 seconds, the breaker is defective. If you don’t want to open up the transformer to replace it, wiring in an external breaker like a Lionel #92 is an acceptable substitute.
Setup for accessories
Many of the accessory outputs for Lionel transformers bypass the built-in circuit breaker. When you use these outputs, It’s critical that you use a circuit breaker for protection. In this case, it doesn’t matter which post you connect the breaker to.
Train direction function
To change the direction of the trains, push the big orange button with the Lionel logo on it. This interrupts power, cycling the train’s reverse unit.
Circuit breaker function
The circuit breaker trips after a few seconds when a short circuit occurs. Fix the cause of the short, then press the orange button with the Lionel logo on it to reset the breaker. The transformer will resume functioning at that point, providing power to the train and accessory.