tmcc and o-27 switches

[Anonymous]

While reading about the SC-1 in the Trainmaster manual, it says that all switches should be wired using their fixed voltage terminal, not track voltage.

Does that mean I can't use postwar O-27 switches without rewiring them to fixed voltage?

[wrmcclellan]

plasticlizard,

PW 1122 0-27 switches get their power internally from the switch center rail.

You have to disassemble an 0-27 switch and make some cuts and add a wire to have it work with constant voltage. I thought there was an article either in CCT, OGR or CTT/OGR forums recently about how to do this. I tried to find the reference but no luck.

There is also an article on Lionel's website about how to do this. http://www.lionel.com/ForTheHobbyist/Findex.cfm
This is in FAQs in the For the Hobbyist section.

I looked at one of my 1122 switches and my opinon is the Lionel approach may not be possible on all of them as the amount of wire available to pull out may not be the same or sufficient for you to get a grip on it. Plus if you mess up, you will have to drill all the rivets out on the switch to get into it to repair. A particular problem with this is that a couple of the rivets go to the cast metal switch frog and one of the controller screw terminals. One may have difficulty re-swagging these back into place.

On a 1957 unit I have, it is not possible to pull the wire out as Lionel recommends.

The good news is an SC-1 (or SC-2) will still work for you as long as the track voltage is high enough to throw the switch. Look at your SC-1 diagram in the SC-1 manual. From the 1122 switch, you connect the closest terminal to the 1122 switch motor housing (This is the only terminal of the 3 that has a metal plate under it - the other two have the plastic base under the screw terminals) to the common (COMM) of the SC-1. Connect the other two 1122 terminals to either the "through" (THRU) or "turn-out" (OUT) termnals of the SC-1. Once you see it switch with the CAB-1 , you may need to reverse the two.

Be aware that some time back there was a problem with SC-1s and switches. Something to do with the terminals on the SC-1 tied together that could short the power supply in certain applications. Lionel provided modifications a while back. I do not think they do this anymore.

Good luck.

[lionelsoni]

Here's an old topic about rewiring O27 switches: http://www.trains.com/community/forum/topic.asp?page=-1&TOPIC_ID=11825&REPLY_ID=87039#87039

[waltrapp]

BTW: since I hogged up most of that thread that Bob pointed to [:D] let me add here that I bought components to do the six Lionel 42" O27 switches that I have. I successfully altered one switch and things worked as planned. Actually I applied the components to the 27" switch that I talked about in that thread, since it was already "disassembled", and have not yet attempted to find the 'middle coil wire' on the O42s.

I don't recall which it was exactly, but there's a slight delay before you can switch the switch either right after you first power up or maybe it was right after you switched the switch and you want to switch it again, but the delay is a short one and a darn SMALL price to pay to NOT have to listen to the incessant buzzing!!

Thanks for all you help that you guys gave to me when that thread was active and hot.

- walt

[lionelsoni]

It's both, Walt. The capacitor needs a second or two to charge. On the other hand, I find that I can throw a switch without turning on power for a day or two after I have shut it off!