# ZW 250 Transformer Hum and Saying Hello



## brubakes (Feb 16, 2016)

I've only really knew O scale as what my grandfather put around his Christmas tree as a child. I was into HO when I was growing up. Grandfather is gone now and this past Christmas I wanted to run the Lionel stuff he left for the family. Opening the storage container the items were wrapped in newspaper from 1994 which would be my guess the last time the equipment was used. I dusted it off and did the quick once over and it fired right up no problem. Ran perfect for the whole season. Now the locomotive is in for a cleaning, tune up, once over at the local hobby store. First time its been in for service (that I know of) in 35 years. So the Lionel bug has bitten and since early December I've been picking up post war Lionel when I can. I'll never pack granddads train away again, only in a display case I'm building. So... way off track here (no pun intended).

I picked up a ZW 250w transformer for more then I should have but oh well. It seems fine, but wondered if it should have a constant hum when its plugged in? I know its significant more powerful then my 1033 transformers so wonder if its normal operation? - See more at: http://www.lioneltrainforum.com/tm-...ransformer-hum-and-saying-hellog/msg1263/#new


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## teledoc (Oct 22, 2014)

A majority of the older Lionel Postwar transformers do hum, when plugged in. Some are noisier than others. Sometimes you can just give it a quick smack with your fist, and it may quiet down. Considering that it is the 250W version, has it been thoroughly checked out, for frayed wires, etc. Are the contact rollers flat spotted. If you haven't had it thoroughly checked out, I would suggest you take it to a Lionel repair facility, and have them check it out thoroughly. But as far as the hum, it will to a point, while it is plugged in. I would suggest that you plug it into an outlet that can be switched off, when it isn't in use. This way it isn't constantly powered up.


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## sjm9911 (Dec 20, 2012)

Good info on zw here http://www.tranz4mr.com/ZW_Page.html unfortunately the 250 isn't one that can be hushed. Check out the tread anyway, as you can check it out yourself. 
Doc, I till got to look for that train. Soon, I hope!


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## teledoc (Oct 22, 2014)

Sjm9911, I forgot about that link, and it's good advice about the transformers. I have the 275 watt ZW, two KW's, and a bunch of small 40-60 watts small transformers. I don't notice any obnoxious humming.

As far as looking for your version of 1688, don't sweat it. I went back to older threads, and found what I was looking for, in one of TJcruiser's old threads. His thread with "third chances", is the exact motor, and the way it mounted. Most people think that the 1688 only has two style motors. There were three styles used, and the one in TJ's thread is the second version. Of Lionel's Prewar trains, I know just about everything related to the 1688/1688E and that body style that they made.


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## Dave Sams (Nov 24, 2010)

Brubakes

Welcome to the forum.

I'm a fan of the 1033's. You can run 2 PW engines at once with one. The limitation is the number of accessories they will power. But, you can get one for $25 or less if patient.

Humming is normal. As someone said, usually it is something loose and a little fiddling or a good smack will either fix it , or make it worse. My 45 watt transformers are most prone to humming, but easy enough to fix.

If you are going to build a collection and a layout, you should learn how to do your own servicing. For what you will likely pay, you can buy a nice PW locomotive. Spring and summer are the best times to buy. I bought a complete Capitol Limited set without any sign of wear for $85 shipped.

Have fun!


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## gunrunnerjohn (Nov 10, 2010)

Some transformers hum, and some can't carry a tune. 

Seriously, some will hum louder than others. The construction as well as the case and any magnetic parts that are loose. Some core lamination designs are more prone to hum than others. I know the old ZW models typically had more hum than the updated ZW(R) due to the different core design. The core laminations actually change shape as the magnetic field changes, depending on the design and how it's mounted, you'll get more or less hum.


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## DennyM (Jan 3, 2016)

My ZW hums, some days are louder than others, but not to the point of being annoying. This is my next ZW purchase. Mainly because it has a button for the bell. Hopefully I can find one at York in October.


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## /6 matt (Jul 7, 2015)

All transformers hum, its the nature of AC. The more wattage the louder the hum. Your trainset transformer is no exception to the rule.


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## gunrunnerjohn (Nov 10, 2010)

I have the ZW-C part Denny, but I'm keeping the bricks.


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## DennyM (Jan 3, 2016)

gunrunnerjohn said:


> I have the ZW-C part Denny, but I'm keeping the bricks.


That's like selling someone a gas can, but gluing the cap on it.hwell:


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## gunrunnerjohn (Nov 10, 2010)

I don't have any gas to spare.


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## brubakes (Feb 16, 2016)

Thank you everyone for the info and responses. I was using the ZW on my little test layout (5'x5') and it seems to function just fine so far.


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## phillyreading (Aug 25, 2015)

The 275 watt post war ZW and the 250 watt are about the same except(might be one minor difference) for the power rating, everything should be close to the same inside them.
Some transformers hum and some don't. Check the mounting screws on both the top and bottom, yes there are 4 more screws on the bottom of the post war ZW. Take the top off and the bottom screws out and I think the transformer coil will come out, there might be more to do but I can't remember if there is.
Don't put any insulation inside to quiet the ZW, it may catch fire.

Lee Fritz


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