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Hi! TinMan here. We have  sold hundreds of ZW 250/275 transformers in addition to the several hundred units we have refurbished for customers.  An issue that has occasionally popped up is when either or both the whistle controls are pushed all the way forward it causes the power to the center rail to shut off. 

We have identified the culprit as being the spring in the Whistle control that is responsible for returning the lever to the center position. This spring is also supposed to control the maximum forward movement of the lever. What happens after extended use one of the arms of the spring bends, and allows the control lever to go further than it supposed to.

The spring is super strong, and we have been unable to bend it back to it's original position. We tried every way from breakfast to re-bend it with no success. On a trashed control we were able to bend it back using a micro torch, but in the process damaged the fiber switch housing. Ended up advising customers just don't push it that far, the whistle will still work just fine.

A couple of Sunday's ago we made it our mission to find a solution to the problem once and for all  and were successful. The solution was so simple it is embarrassing.

We took a piece of insulation from a stranded wire cable, and inserted into the switch assembly which prevents the full travel. A 5 cent part solution most anyone can do themselves.  We have a detailed description of how to do this with a photo on our website ( under tech tips, transformers.   We are now adding this feature to every ZW  we work on. In addition, if the transformer was refurbished by us, and you are a little nervous on doing this repair, we will take care of for you at no charge. In addition,  if after checking out the site, you  cannot find the correct wire insulation needed, drop us an email ( and we will mail you the part needed for both sides free of charge, regardless if it was one of our transformers or not.

And finally keep in mind!


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OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
800-980-OGRR (6477)

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