ZW transformer

Generally, refurbishing includes a new cord and at least new rollers. Some mods are often done including the whistle rectifier replacement to a modern silicon diode and a new, better, breaker.

 It sounds like it doesn’t have many miles on it. Take a look at this website for additional detail.

http://www.tranz4mr.com/ZW_Checkout.html

Here are the essential items to look at to make sure it’s safe to run:

1. Power cord. If there are any cracks in the cord, replace it before you plug it in.  

2. Before plugging it in, unscrew the 4 screws in the top and take the cover off. Look at the rollers that touch the winding in the middle.  Move each of the handles back and forth to see if the carbon rollers are round and rolling or flat and sliding. If flat, they need to be replaced. If the transformer is used with flat rollers, you can damage the winding, and then you may as well go shopping for a new transformer. 

3. While you’re looking under the hood, check for any obvious loose wires and correct if needed.

3. If the above 3 items check out, plug it in. Then test the internal breaker by turning one of the handles (let’s use A as an example) to about 14volts. Take a screw driver and touch the A binding post and one of the common posts at the same time.  The breaker should trip in a few seconds. You’ll hear a click/ping and the red light on the left of the zw should light up. Remove the screw driver and return the power to 0 volts. You should hear a click and the breaker should be reset. 

Do you plan to run postwar or newer locomotives?  If postwar you’re likely good to go.  

If newer trains will be run, you will want to take addition precaution by adding fast trip breakers on each power line and TVS diodes.  I won’t get into that unless needed.

As CJACK mentioned, you can do a full refurbish/upgrade if desired/needed.