My conventional layout is currently powered by two 1950’s vintage ZW’s both working perfectly. I’m thinking of adding a new CW-80 transformer to power just the accessories. Should I establish a separate common and wire all the accessories to the CW-80 or link the new transfomer to the existing common bus shared by the two ZW’s and then move the accessories from the ZW’s to the CW-80 (or maybe it doesn’t matter)? I’d appreciate any advice.
Bob
I use the same common. I have a ZW & 1033 so I can run three trains at once, if I want. I use the the fixed power posts on the 1033 to run 11 and 16 volt accessories.
wyomingscout
If none of your accessories are activated by control rails, there is no reason why they have to share a common with the track. However, it can be handy to be able to use the same wire or the outside rails as a return rather than running a separate wire. Furthermore, far from increasing the current and the voltage drop in the return path, the accessory return currents will to some extent cancel the return currents from the trains if you arrange the accessory transformer to be out of phase with the track transformer(s).
Bob,
Could you elaborate on your last point a bit? The two ZW’s are in phase now but the plug on the CW-80 can only be inserted one way. If I use all three on the same common bus can I assume the CW-80 is in phase with the other two just because it can only be plugged in one way?
Bob
If the CW-80 is out of phase, just reverse the plugs on the two ZWs.
Have you considered upgrading you motive power to say a MTH Z4000 and then using one of you ZWs exclusively for for accessories, signaling, switch motors. stationary smoke machines, static lighting etc? After all, even after replacing the power chord, circuit breaker & rollers, a ZW is still a 50+ yo high current electrical appliance. One Z4000 will give you superior safety protection and enough power reserves to support serious future expansion. [8D]
To add to James’s answer, no, you can’t assume any particular phase relationship between the CW-80 and the ZWs. You will have to test.
In fact, I would not even assume that two CW-80s (if you had them) were wired to their plugs with the same polarity, although it is likely that they are. There was a fiasco early in their history involving the identity of the common terminals and the polarity of the whistle signal. I would be especially cautious in using an old CW-80 with a new one without testing. It is also possible that Lionel would change polarity at any time for some manufacturing reason, or even randomly if the assemblers are allowed to connect the power cord or the transformer windings either way or if the transformer polarity is not specified to the transformer vender.
(I just realized that my use of the word “transformer” may be confusing. There is an actual transformer inside a CW-80; but I consider the CW-80 itself to be a power supply, not a transformer per se, by virtue of the considerable electronics between the actual transformer and the outside world. Earlier transformers are just that, transformers in Bakelite boxes, with minimal added gizmos.)
I use a CW 80 to power several accessories and haven’t maxed it out yet. I connected the track posts to a terminal strip and started adding accessories. I am at about 10 of the “always on” types (beacon, lamps, pylon etc) and I’m sure I can add a few more before the transformer folds back.
I would caution against using transformers out of phase. What Bob Nelson says is correct as far as the current the ground return. However, the voltage across the two hot terminals is now the sum of the voltage outputs of the two transformers, and it could be as high as 40 volts. This is too much for safety.
Actually, it could get to barely 50 volts using a couple of type-Z transformers, which Lionel claimed put out as much as 24 volts but whose dials are marked to 25 volts. But 50 is the lowest voltage that the National Electrical Code considers dangerous:
110.27 Guarding of Live Parts.
(A) Live Parts Guarded Against Accidental Contact. Except as elsewhere required or permitted by this Code, live parts of electrical equipment operating at 50 volts or more shall be guarded against accidental contact…
Forty-eight is the DC voltage that virtually all common-battery telephone systems use, with no particular protection against contact.
As a practical matter, it is unlikely that one would get across even 50 volts. The sum of track and accessory voltages will rarely get above about 30 volts. Furthermore, although the track voltage is everywhere out in the open, the accessory voltage will probably be exposed in very few places.
I am using a newer ZW for track power and 2 CW80s for accessory power and they are all in phase. Just check the outputs at each terminal of each transformer to match them up and you should be good to go.
Jeff
I’m afraid I don’t get your point, Jeff. Could you explain a little more fully?
The wall socket plugs are oriented a certain way to plug into an outlet, so one cannot reverse the polarity output of the transformer by the way that the transformer plugs into the wall. However, there were some older CW80 units that we wired “backwards” from the factory and their output is reversed, so they might not phase with another newer CW80. So the best work around is to use a suitable meter to measure the output at each terminal of each transformer to determine all the hots and all the commons. This will ensure that all the transformers are in phase avoiding any potential issues.
Jeff, you can determine which are the common terminals with a voltmeter or ohmmeter; but I don’t see how that ensures any particular phase for the non-common output terminals. The manufacturer can have altered that simply by swapping a couple of wires in several places. If the phase is not how you want it with the commons identified and connected, the only way to fix it, short of rewiring the innards, is to swap the power-cord conductors or plug transformers into different phases of your residential service.
Speaking of that, if the “potential issues” to be avoided include having accessories out of phase, consider that half of your house is wired out of phase with the other half, with no ill effects and some considerable benefit.
I would rather run seperate wires for the CW-80 and not try to phase the older ZW’s with the CW-80. The CW-80 will not work properly with many of MTH engines, so I am taking a guess that it may not have the same kind of power output or have some newer electronics inside it that may not play well with the older ZW’s over a few years time. Also the possibility that the CW-80 may throw the circuit breaker on the older ZW.
Lee F.
Lee,
If my conventional layout uses a common buss and the accessories are tied to that common buss then I guess your option doesn’t work. I may be forced to inlcude the new CW-80 in phase with my older ZW’s. Is that accurate?
Bob
Bob,
What I am saying is to play it safe and use a seperate set of wires from the CW-80 to any accessories because the older style ZW’s may not like the newer transformer’s output. The old style ZW is likened to a brute in output with only one circuit breaker on the return side, even though it has four power levers. The CW-80 has at least one or two circuit breakers in it and it uses some form of electronics that may send a false signal(electronic stuff may impose a small DC voltage on it’s output) to the ZW and trip the breaker, or you may have the CW-80 burn out after up to three years for no known reason. My thinking is to save your equipment and use the extra wire compared to the cost of buying a new transformer.
This is from personal experiance; I was using two small 12 volt DC voltage transformers from Radio Shack on my layout, one I had wired with a common negative with a Lionel transformer (AC voltage) and I lost my transformer from Radio Shack, looks like I fried the rectifier circuit in the Radio Shack unit.
What I have done with my post war ZW was to add in 10 amp circuit breakers on each output terminal, from a company called Scott’s Odds and Ends.
Lee F.
Thanks Lee. That’s very helpful advice. I’ll give it a try.
Bob
Lee, you can run all the separate return wires that you want–it’s your layout–but there is no reason why one cannot use a common return for various power supplies, whether a transformer like the ZW, DC supplies from Radio Shack, phase-control power supplies like the CW-80, any waveform, any frequency. I doubt that that was the cause of your Radio Shack “transformer’s” failure.
The CW-80 has an electronic fold-back feature, no circuit breakers. I can’t imagine how sharing a common could trip your ZW’s circuit breaker; and I don’t think you have any justification for predicting that connecting its common to a ZW will burn it out in three years.
I use a DC supply for my turnouts, which share a common return with the track. (Otherwise the non-derailing feature would not work.) No problem.
Separate circuit breakers on a ZW’s outputs are a good idea. You can get entirely suitable ones from most automotive-parts stores.