Overhead wire

[JorgeC]

Hello Everyone,

I know that this has probably been beaten to death already, but I have a steeple cab electric that runs off of overhead wire, but I dont know how to wire the overhead. I have done alot of reading regarding this topic, but I'm still alittle lost . The layout is wired as one live block that runs off of an MRC Tech II 2500 power pack. I want to wire just one siding for overhead, so I can run the steeple cab and still be able to run a diesel into the siding if I need to. I hope I get it this time

Thanks,
Jorge

[jetrock]

Trolleyville has some great tutorials on hanging overhead wire in the Library section. You might have to rewire the steeplecab, as equipment wired for overhead power have both sides of the wheels ground the same (for example, the overhead line is + and both rails are -) or at least change the wheels. I'm going to run into the same problem (I want to run trolleys and steeplecabs as well as diesels) and I'm still thinking about solutions. Probably the best way would to use conventional wiring for the rails, and then rewire the loco so it only picks up power from one side of the wheelset (this might require a change of wheelsets.) Although if you're running DC you'll have to have some way to get the steeplecab off of the siding if you're going to run the diesel onto it.

[bill937ca]

It can be done, but gets complicated. In a straight overhead only operation the return current goes through the rails and the rails are electrically connected as a single circuit rather than isolated as in two rail.

[60103]

Jorge, a lot will depend on how your steeplecab is wired. I've had a number of trolleys where the pole was just fastened to the brass body and it required a pile of work to insulate it and wire it.
If the loco is wired for 2-rail now, you can just hook one side of it to the pole/panto instead. Then you can run it facing one way and also run the diesel.
If the two sides of the wheels are already wired together, you could use a DPDT switch (or SPDT) to connect the power pack to either the one rail or the OH. Or you could have the OH always live and just switch the rail around. You might want a dead end section to put the electric loco while you run the diesel.
There are tons of ways to do it.

[steamhead]

David has the easiest solution. Wire the track through a DPDT so in one position both rails are grounded, and the in other position they're +/-. If you use a DPDT center-off, you can kill power to the rails to avoid any accidental running of either type in the wrong track condition.

[JorgeC]

Hello,

I unfortunately made a mistake. The steeple cab is not wired for overhead. It still takes power from the rails. If I make one rail negative and the overhead positive and run it off of a seperate power pack will I still be able to run a diesel and the steeple cab at the same time on the siding?

Thanks,
Jorge

[jetrock]

Running it off a separate power pack isn't advised unless you electrically isolate a block and use a DPDT switch to control which power pack controls the block. I suppose it would work a bit like a "common-rail" system but generally if you want to run two locomotives independently on the same piece of track, you want to go DCC.

[steamhead]

Why would you want to do that if the steeple cab is not wired for overhead? Just wire both rails in the usual manner...

[steamhead]

Ohhh...At the same time....You would have to re-wire the steeple cab, and...?? I' don't think so, but then...?? Maybe.

[60103]

Jorge: So is the overhead pickup linked to the body which is grounded to one side of the wheels? It looks like the steeplecab would then take the power from the OH and send it to one rail where it would run the diesel.
I've had a couple of trolleys wired that way; they never went past the disassembly for painting stage and are awaiting some sort of redoing of the pole mounts. (They've been waiting since about 1972).
A really ambitious conversion would involve taking off the body and re-mounting it with a rubber or plastic sheet between it and the chassis and replacing any metal screws holding it down with plastic ones, then taking the pickup from one side off the wheels and onto the body.