zw problem

HI

  pull the 4 screws off the top  and check and see if the carbin roller fell appart.

 that is what we find appart in side on alot of the ones that have not been serveced for years.

 or you can dring it to us to rebuild and go over we warnty every thing we do.

 HENNINGSTRAINS.COM or bring in to store. (215)-362-2442.

First, you should have checked it before you bought it. Sounds like a lose bulb that may have fallen out of the socket. Very unusal for a roller to fall apart.

If the rollers are not good, do NOT use it until you replace them.  The arms will score the windings and can destroy the transformer.

i checked it out.  it was just a piece of plastic.  but it registers 3.4 volts when it is on off. is it possible to adjust the arms so it is goes to zero?   

btw i did check it out when i bought it.  just not with a voltmeter.  

Note that you need to do the measurement with at least a light load on the transformer.  Stray fields will give you a reading on most meters if the transformer is totally unloaded.  Put a small light bulb across the output and take the measurement, I'm pretty sure you'll find it's zero as you expect.

It should read Zero on a ZW, though, as the circuit is supposed to be totally broken with the dials all the way down.  There is a chance that heavy carbon tracking could give some indication, but I've never seen it, and it wouldn't be with such uniformity across all 4 taps.

It sounds like the coil assembly has shifted inside the case from a drop during shipping or otherwise.

There are now two threads going on the same issue.

I understand that the original poster is probably anxious to get his problem resolved, but keeping his ZW issues to one thread would have been better.

Wrong, and that's exactly my point.  I have a ZW sitting on the bench here.  I can read resistance across the outputs with the throttle totally closed and I have infinity.  However, I can power it up and I'm getting about 4.4 volts AC on a Fluke true-RMS bench meter.  As soon as I add any resistance, a 1K resistor does the trick, it drops to the correct reading of zero volts.

quote:

However, I can power it up and I'm getting about 4.4 volts AC on a Fluke true-RMS bench meter. 

Would you expect to get similar results with an analog meter, such as a Simpson 260?

With my 260, I get zero.

Perhaps an analog meter puts enough load on the transformer to get a zero reading.

Other than a Harbor Freight Freebee, I don't have a digital meter.

Yep, the analog meter doesn't respond like the digital ones, it presents a very light load, but a load in any case.  This is not a transformer issue, it's just the nature of the beast.

I just did the same test on a KW that's sitting on my bench, that one gave me over eight volts.  The same 1K resistor drops it to zero.  It also reads a total open circuit with the throttle closed.

I'd like to know how Traindork made out with his ZW transformer.

Please let us know.

I tried a cheap digital meter on a ZW and got readings of up to 18 volts open circuit, depending on where the other dials were set, on A-U with the A handle in the off position!

The easiest way to check if there is Voltage with the handles in the closed position is put a 12 volt light bulb across a-u and if it lights it isn't zero. If it lights very dimly it may need an adjustment of the roller. If it burns out you have a bigger problem than an adjustment. If you can't see any light or feel any heat on the bulb after a minute your a handle should be good. Go on to each other handle and do the same. Meters are fine but they don't always do the job that is needed. John is right on the loading and this should load it and check it at the same time. Don't try this with a 12 volt bulb and the handle fully on. If you want to check the handles for smooth voltage change get an eighteen volt bulb and run the handle all the way up and look at the output. Easy and cheap.

Ron

i need to do the bulb test today but so far it seems like the ZW is running fine.  so i will let you guys know more latter today.  and i will post some pics of it and some of the other things that i found at the show that i went to  

yep that bulb test worked out great.  so here are the pics that i said i would post.