ZW REPAIRS

You dont say which handle is dead.  Is it dead from end to end, intermittent?  Best guess is the cabon(?) roller is missing or the roller arm is broke or bent so not touching the winding.

Take the four screws out of the top cover/ and Lift it off. and look inside-

On Each side of the transformer there will be two arms that connect to the two outer handles. Check each arm to see if there is a roller attached to the arm and to see if the arm is intact and no problems exist there.  If all is alright there then we need to look at the Screw Terminals which are A-B-C-D and U marked on the outer case.

If these Posts or Nuts move or come out in your hand then you have found the Culprit. If one of these is the Culprit then there are two options:

!. Contact a Train Transformer Repair Person and let them repair the posts for You

2. Contact a Transformer Repair person for the Studs to replace Them.

The last thing is that to check to see if the Wiring going to the Copper strip in front where the Power is hooked too to make sure that Both Wires are connected to the Copper Strip Both Top and Bottom you can see all of this from the open top of the Transformer.

Web sites of Reputable Transformer Repairs that I have found are

http://www.tranz4mr.com/site/Tranz4mr-Home.html

http://www.lioneltransformer.com/home

Wish you luck and Great Fortune finding a ZW in workable condition for 5.00 the Train gurus were looking over your shoulder that day.

These are the best options There is another one that you can do yourself if you choose.  Shoot me either an E-Mail or say something here and I will go over What i did to Fix My ZW Binding Posts.

Dan,

   What a great pick up, for all the money you saved on this pick up, you can afford to have the transformer completely over hauled by a pro, have been running trains all my life, and never ran across a pick up like you just made.  Congrats on picking up your ZW,

I would have her completely restored, ZW's are great for running DCS!  I even upgraded mine with Banana plug connections.

PCRR/Dave 

Man, for $5 I'd jump on it in a heartbeat!   I think when you open it you're going to find the wire is off the back of the terminal at the rear, an easy fix.  There are replacement posts that cost around $1 and are easy to install with no additional disassembly.

It is essential to check for worn rollers, since damage to the winding is said to be irrepairable.  The U-posts are rivetted to a bus bar, and the rivets fail.  Test with a resistance meter.  As Pine Creek says, this is an excellent transformer to use with DCS, but, since the internal breaker is worthless, you must use external fuses or breakers on each A,B,C, or D post; I wouldn't use over 10-amp rating.  If all U connections could also be fed through a single 10-amp fuse or breaker, that would be worthwhile, since 10-amps flowing through A,B,C, & D would equal 40 amps, far beyond the ZW's capacity

Uhh... not really!  The U terminals are the common return for all the outputs, and any current from any of the outputs would have to flow through the 10A fuse.  You need to fuse each output individually.

A bit of both is best.  Some 10A fuses on the A-D outputs will protect the loads, and a 15A circuit breaker on the combined U returns would protect the transformer's windings.

I would recommend against fusing the "U" side only, even with a seperate fuse for each "channel". IMHO, its better to fuse each of the terminals "A" through "D".
This is because it is easy to accidentally create a circuit between any two of the "A" through "D" terminals.  A fuse on the "U" terminal would not help.

gunrunnerjohn:  Note that I did say (you didn't quote it) that A,B,C,D should all have their own breakers or fuses and "also" the U circuit protection would be a good idea. 

Consider this: the ZW has a single set of secondary windings.  If I have A,B,C, & D all set to 16 volts and all feeding 9 amps, none of the output fuses will open, but I'm feeding 36 amps through the coils, which is definitely an overload.  If the internal breaker were working properly, which might happen occasionally, it would open since it is in the U circuit.

Now someone might say, why just just put a fuse/breaker in the fuse line.  Consider this scenario.  A layout has 2 loops, one controlled by A and the other by D.  A is set to 16 volts & D is set to 7 volts.  A loco is crossing between loops and for some reason stops with its rollers crossing the insulated gap.  You now have a dead short between A & D, at a voltage of 9 volts.  This is why there should also be fises/breakers on the 4 ABCD posts.

What is the max amperage a ZW can take.  In Model Railroading, the Lionel Bantam book printed in the late 1940's and reissued in the 50's, Lionel said that its transformers should not be operated continuously at more than 75% of rated capacity.  So the 275-watt ZW (there was an earlier 250-watt version) should not be operated at more than about 206 watts.  The max voltage output is 20 volts, which means that the windings can continuously carry 10.3 amps.  If the voltage is set lower, the wattage decreases but the wire diameter is such that it still should not carry more than 10.3 amps.  Running at a lower voltage but drawing higher amperage will mean oputput is with the 206 limit, but the wires will be overheated in the area between the end of the secondary (the U post) and the location of the roller.

As mentioned in the previous post, you have to fuse each circuit anyway.  Also, if the circuit breaker in the ZW isn't working, I'd suggest that be remedied before use anyway.  With the internal CB working, fusing A through D is sufficient IMO.

I agree that most PW transformers will not deliver the nameplate wattage, that's input watts, not output watts.

@  van d.   rjr has it right.   but at the least, pop the top off and have a look..

As far as I am concerned, the most important test hasn't been mentioned yet.

The transformer should be checked for AC leakage, and the cord inspected. If the cord is cracked or brittle, it should be replaced.

Dan,

  Gun Runner is absolutely correct, fuse or breaker each out put to safe guard everything.  Running in this manner I have never had a single problem with my DCS,

do not take a chance on setting up in a different manner.  Send your ZW to Super Dave and let him over haul it completely, you just saved big time on your pick up now let Dave

restore the ZW completely.  CW Burfle is absolutely correct also, everything should be checked out and restored to the as new condition.  Great find once again sir!   If you look at my picture of our power desks, you will also see a KW that works well with

DCS, when safe guarded in the same manner.  If you see an old Lionel KW in those shops you vist, for the same kind of money, that would also be a big time transformer pick up for powering different parts of your layout.  The old KW transformers were serious quality power stations also.  Dan also remember old ZW's come from two different generations with slightly different total power ratings.  The older model is less powerful

than the later ZW, my picture shows you both the old type ZW transformers, both are high quality transformers.  Long ago I posted how to up grade the old ZW's with Banana

plug couplings, and gave a complete engineering picture of how to accomplish the work.

Really a slick up grade to the old ZW & KW trasformers.  The old ZW's & KW's can be used without the Banana plug up grade, but its sure nice to have them for repeat usage when building repetative DCS layouts. 

          PCRR/Dave

I'm not so sure that the internal circuit breaker of the old Lionel transformers can ever be made safe & reliable.

C W is right about the cord.  I have a 1941 Type R that I use on the test bench, but as I recall it would be very difficult to replace the cord due to how it's attached to the primary winding.

While we talk about the classic ZW, there is also an earlier Type Z of 250 watts. With external fuses/breakers and an internal wiring check, it would also be quite suitable.  There were a few Type V and Type VW made, at about 150 watts, but they are very rare.

My "repair" for old PW circuit breakers is to install a more modern breaker in it's place.

That makes sense

I've successfully replaced the cord on a couple of ZW transformers without totally removing the core.  It's somewhat of a PITA, but it can be done.

Hi Dan, What did you find when you took the top off the ZW? Could you see a fault?

    What did you decide to do?

    Very best, Don Johnson