Steve -
The Home Owner service manual has a short write-up under the heading "Circuit Breaker CB-3" which indicates that there are actually two protective devices on the E-20 motor. One, designated CB-3 on the diagrams, is an internal thermal switch. They say it trips "if the motor is overloaded for a long period of time" and that it auto-resets when cool. From the schematic, it is in series with the brake switch and should have the same electrical effect as stepping on the brake. CB-3 is wired on a 4-wire plug going into the motor along with the two field wires.
Meanwhile CB-1 is the Klixon-like unit mounted on the outside of the motor. The book doesn't way much about it, but from what I can gather it is a typical thermal breaker. It will trip when the current passing through is high enough to heat it to the trip point - much as a breaker in a household circuit panel. I assume that mounting it on the motor is intended to give it some sensitivity to the motor temp also. It looks like it is wired to protect about everything except the lights and the PTO in the factory wiring. I assume that yours took out the lights too because of where you picked up the 36v for them in your rewiring.
That would seem to say that if there is an internal adjustment bolt it
would be hard to know where to set it.
BTW, the model number you got off of yours agrees with what I see on the E-20 motor that I checked. One more item to see if we can find a handy source.
- Tom Coate
Leesburg, VA E-20
_______________________________________________
Elec-trak mailing list
Elec-trak cosmos phy tufts edu
https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak