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ZW 275 watt Transformer

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Saq
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ZW 275 watt Transformer
Posted by Saq on Thursday, March 26, 2009 8:40 PM

Question I am wanting to know if a ZW transformer is ok for a 11 1/2 X12 ft, O27 gauge room layout with 3ft wide tables placed against the walls. Is this too much transformer or will something smaller work?

                                              Clint  Cool

Saquili
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Posted by ADCX Rob on Thursday, March 26, 2009 9:08 PM

The size of the layout is irrelevant.  It is more important to assess your power needs.

I  can't think of any situation where you would want to shy away from the largest, most powerful transformer(s) you can afford/acquire.

Rob

Rob

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Posted by ChiefEagles on Thursday, March 26, 2009 10:02 PM

It will take a lot to "overload" a Post War ZW.  Running conventional, should be OK.  Command, better get some fast acting breakers and TVS's between transformer and the track.

 God bless TCA 05-58541   Benefactor Member of the NRA,  Member of the American Legion,   Retired Boss Hog of Roseyville Laugh,   KC&D QualifiedCowboy       

              

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Posted by phillyreading on Friday, March 27, 2009 7:12 AM

Depends how many trains you want to run and if you have lighted passenger cars. After a few months you may want to buy another transformer to handle all your needs.

Lee F.

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Posted by Ole Timer on Friday, March 27, 2009 9:58 AM

Saq ... no it's not too much in my opinion ... believe me you'll want and need it later . As the other guys said ...  that way you'll always have a bit more than you need ... well until you expand alot ... have full power to all your engines - cars and lighting . Every little addon consumes power and you don't want to overload or have those engines underpowered . If I'm not mistaken those 275 ZW 's are only putting out about 180 for useage ... I don't know why they confuse folks by labeling them 275 ? And they can get HOT if overloaded .

       LIFETIME MEMBER === DAV === DISABLED AMERICAN VETERANS STEAM ENGINES RULE ++++ CAB FORWARDS and SHAYS
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Posted by phillyreading on Friday, March 27, 2009 10:25 AM

Ole Timer

Saq ... no it's not too much in my opinion ... believe me you'll want and need it later . As the other guys said ...  that way you'll always have a bit more than you need ... well until you expand alot ... have full power to all your engines - cars and lighting . Every little addon consumes power and you don't want to overload or have those engines underpowered . If I'm not mistaken those 275 ZW 's are only putting out about 180 for useage ... I don't know why they confuse folks by labeling them 275 ? And they can get HOT if overloaded .

I have not had a 275 watt ZW got hot, just warm to the touch, only the short circuit light came on after a derailment. Probally the reason they are labelled 275 watts is because that is how much watts it uses(or draws from the wall outlet) on 120 volts.

Lee F.

Interested in southest Pennsylvania railroads; Reading & Northern, Reading Company, Reading Lines, Philadelphia & Reading.
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Posted by lionelsoni on Friday, March 27, 2009 4:41 PM

One reason that older transformers might get hot is that they were not designed for modern line voltage, which has crept up 5 or 10 volts from what was expected.  The ZW, for example, was labeled for 115 volts.  One-twenty is now the standard, with many actual services getting 125 or more.  Toy train transformers, like most small transformers, are designed to waste some power by going partly into saturation, in order to make the transformer smaller and cheaper than it would otherwise be.  Unfortunately, how much they saturate is pretty sensitive to the primary voltage.  This power consumption goes on whenever they are on, whether or not you are using any power out.

There is a simple way to lower your line voltage, which I'm not going to describe.  If the word "autotransformer" tells you what I'm thinking about, you probably know enough about electricity to work it out for yourself.

Bob Nelson

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Posted by Ole Timer on Friday, March 27, 2009 5:59 PM

What i meant by hot is they get pretty darn warm on a large or muti engined layout ... not hot to burn now . You can overwork them ... as any transformer . It's just most new buyers think they are getting the 275 output ... a bit deceiving by lionel if they don't read the fine print . But look at it this way ... there's some of those 30 plus years old and still pumpin out the juice ! Easy to rebuild and dependable as the devil . I'm not downing them . Believe me anyone who bought one way back when got far more than their money's worth .

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Posted by A&Y Ry on Friday, March 27, 2009 7:19 PM

As Lee F. noted, the input of a pw ZW [R model]is 275 watts,whereas the output ranges from 165-180 watts. Also as Bob Nelson noted, the rate of inbound line voltage is a factor. It is 123 V at my house right now but come summertime and very hot days it often drops some by 1 p.m. as air conditioners in homes, offices and Mills create peak demand.

Over time I have found that the pw ZW does tend to get hot and lose some efficiency upon continous running of multiple lighted passenger trains for long periods. Unlike modern units it has no ventilation. But it is a workhorse!

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Posted by 3railguy on Friday, March 27, 2009 10:29 PM
The 275 watt must mean what it draws from the wall. There is a lot of power there however. ZW's have come down in price as well and you can get them pretty reasonable compared to 10 or 15 years ago.
John Long Give me Magnetraction or give me Death.

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