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WHY a hot ZW?
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 I have two ZWs on my layout and one always gets warm after it has been on for a while. The other stays cool. Both seem to have plenty of power and if I switch the loads it does not change the one from getting warm and the other not. They both have new rollers and have been serviced.
I never noticed this until I pulled the one off because of the extreme heat caused by a stuck roller and had it serviced and the rollers replaced. It was only when I started using my back-up ZW did I find out that one does not get hot like the other one always has. Huh?
Any ideas on why??
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One reason for them getting hot is a shorted secondary turn.  Look very closely at the bare track where the rollers contact the coil.  If any of those windings are shorted together, it'll create a lot of heat, and the breaker isn't in the circuit to trip for that scenario.

Sometimes it's possible to solve the issue if it's not too bad.

Last edited by gunrunnerjohn

Thanks for the replies.

One is from 1959 to 60 and the other is from 1965 to 66.

 The older one is the one that gets hot. They are both 275 Watt.

 The guy who did the work is a 82 year pro with transformers, been doing them for 40 years and know his stuff.  I had them both done by him before I used them. Then the one stuck a roller after 6 years on the job and I took it to him and he found the stuck roller. I never told him it always got hot because I thought it was normal.

That one is the one that has always ran warm.

When the roller got stuck it got HOT and stunk.

 The rest of the time it gets very warm but only after 30 minutes or so. About 110 degrees I think. Very warm but won't burn you.

 

Gentlemen,

   Both Guns and Tranz4MR are correct, if the ZW is real hot you have a problem, however some of the early 1st generation 275's run real warm compared to the later ones.  I have both older and newer 275's and a couple 250's also, the 250's never get as warm as my 1st generation 275 does.  It has however functioned perfectly for many many years.

Pine Creek/Dave

Thanks again,

 Took a look tonight and saw some turns that looked like they were touching. Tried to make some adjustments and it seems to be running okay, Don;t seem to have changed anything, I am thinking that Kent is on to something here. I also noticed that this ZW has a running humm that the other one does not.

Yesterday, one of my ZWs got so hot, I couldn’t put my hand on it for more than a few seconds.  The only reason I felt it was because, an MTH RDC would not pull its 3 dummies up a 2 percent incline.  No breakers (internal or external) tripped.  Not sure if it contributed to the problem, but shortly before this happened, I had an engine lock up due to a gear jam, but I hit the REV button on my DCS remote within about 15 seconds.

Today, I tried the ZW with no load.  With the handles at 6V or 20V, it stayed cool for a few hours.  And it put out 19.9 volts on all terminals.  I hooked it back up and ran two trains (on the A and D terminals).  Also had C set at 14 for switch machines and B set at 12 for lights.  It did get hot under load, but not so hot I could not hold my hand on it.  My other ZW (also running two trains) stayed cool as a cucumber.  After about 45 minutes the red light came on.  When I reduced the C post to zero, it went off.  And after about 30-60 seconds, I heard the breaker reset itself.

I got the transformer from Henning’s about 35 years ago and it still has the original Lionel cord so I doubt that it has ever been refurbished.

I’m thinking I will contact Harry Lutz to see if he will take it as a trade in on a refurbished ZW.

HARSH!? maybe. When I was an engineer, for a short time in my engineering career, I was sent out to investigate residential damage claims; floods, fires, roof leaks, foundation and brick issues, etc.. I would write reports to the insurer about the conditions of the residence.

I know you will find this hard to believe but a big part of my investigation centered on "existing conditions." What was existing in that residence that could have caused, for example, the fire (even arson which was also handled by the fire dept.)?

If I found an electrical device as the probable source; the insurer would follow up with the insured with those infamous two words  " NO COVERAGE."

  

@AlanRail posted:

HARSH!? maybe. When I was an engineer, for a short time in my engineering career, I was sent out to investigate residential damage claims; floods, fires, roof leaks, foundation and brick issues, etc.. I would write reports to the insurer about the conditions of the residence.

I know you will find this hard to believe but a big part of my investigation centered on "existing conditions." What was existing in that residence that could have caused, for example, the fire (even arson which was also handled by the fire dept.)?

If I found an electrical device as the probable source; the insurer would follow up with the insured with those infamous two words  " NO COVERAGE."

  

Never heard of an exclusion or no coverage due to damage caused by an electrical device.

My brother is my insurance agent.  He sometimes uses the acronym RTGDP.  It means Read The [Gosh Darn] Policy.  You made me read (well skim through) mine.  I don’t see any exclusion for fire caused by an electrical device, but I’m going to send him a paraphrase of your post and see what he thinks.

Last edited by Lehigh74
@Lehigh74 posted:

Never heard of an exclusion or no coverage due to damage caused by an electrical device.

My brother is my insurance agent.  He sometimes uses the acronym RTGDP.  It means Read The [Gosh Darn] Policy.  You made me read (well skim through) mine.  I don’t see any exclusion for fire caused by an electrical device, but I’m going to send him a paraphrase of your post and see what he thinks.

You won't find it Bob, because it ain't there.

 

John - I won't be running the ZW.  I plan to trade it in on a refurbished ZW.  I'll use a Z in its place temporarily (with a careful eye on the voltage settings) till I get the replacement ZW.

Alan - Here's what my insurance agent brother said about coverage.

I know of no reason, other than arson, that an insured would deny a claim when the damage was caused by an electrical device.

However, there might not be coverage for the electrical device itself.

I guess you can keep your trains…

An update.

I hooked up my Z in place of the ZW, turned it on and after a few seconds a 10 amp fuse (for the C terminal) blew. That circuit only runs a few solenoids, but I was not looking forward to tracing the problem. Didn’t take long though. I had previously been changing some scenery, disconnected a K-Line crossing gate and thought I had left some air between the end of the wires. Apparently not. But that is on a momentary contact switch. Why would there be voltage to it when I’m not operating the crossing gate? So, I measured the voltage with switch OFF and got 1.6 volts. Enough to melt the insulation. I pulled that wire and turned the Z back on. No blown fuse.

I hooked the ZW back up and ran trains for a week with no overheating.

I will still replace the cord for the ZW. When I do that, I’ll take a look at the rollers and coils.

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Bob, shame on you!   I would have thought you'd have checked for that right up front!  When you discussed disconnecting things, I figured we were talking about just the transformer.

A short didn’t cross my mind since I have external breakers AND fuses.  None of them blew when I had the ZW hooked up.  I must have had the voltage just a bit higher when I put the hooked up the Z.  I’m still mystified why I got 1.6 volts with the pushbutton for the crossing gate “open”.  Seems to me it should have been zero with the switch open and 12 with it closed.

@Lehigh74 posted:

Another update.  I removed the cover of my ZW to see what the coils and rollers looked like before I replaced the cord.  The coils look OK, but one of the rollers is flat spotted.  The arm doesn’t touch the coil, but it will if I keep using it.  I’ll trade it in on a reconditioned one on Saturday at Kutztown.

Wouldn't it be cheaper to repair the one you have ?

It’s probably not difficult and surely cheaper to replace the roller and cord myself.  But I’ve never done it before and I prefer to give Harry Lutz the business.  He’s always been fair with me and my guess is that it’s been a slow year with the lack of train meets.  I only had a problem with one of his transformers and he replaced it free even though I told him that I may have caused the problem.  Now, if he offers a pittance for the trade in, I might change my mind.

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