Rectifier Repair

[Uncle]

I am needing a 200Amp rectifier repaired.
I opened it up and one of the transformers is burnt out.
I am not having much luck finding someone to repair it locally.
Can I rewind this transformer? has anyone here done one.
Does anyone know of a shop that can do the repairs?
Brian

 

[souNdguy]

I'm not sure what type of piece of equipment you have..

A rectifier converts ac current to dc current..via tube or semiconductor.

transformer is a different beast.

yes you can get some transformers rewound.. usually cheaper to buy new though when you see the bill.

post more details.. we don't charge by the word.. the more details you post.. the better the answers you get.

soundguy

 

[Uncle]

The rectifier is used in my plating work.
It's 220 1 phase input with 200 Amp 0-25VDC output.
The transformer is the stepdown transformer.
I have not been able to find a direct replacement as I can't find any numbers on the transformer and the Rectifier is only marked with a model number and no Manufacturer.
Brian

 

[RayP(MI)]

Transformers can be rewound. I have used transformers from old tube type TV sets to make 12 volt powersupplies. You have to burn the old transformer in a trash fire until you can get it apart, burning out tar, paint,etc. Then you can dismantle transformer. Make your own spool out of cardboard over a wood core the same size as the transformer cores. Then you'll need to wind proper number of turns in primary and secondary windings, using wire appropriate to current carrying needs. Then you'll assemble all those metal E pieces over the new wound coils. add the covers, and bolt everything together. Be sure to properly insulate leads off the coil. Magnet wire of proper sizes is available at electric motor shops. You may want to seal the coils, and so forth with some kind of heat resistant glue. Formulas are available to relate number of turns to volotages. Charts are available as to wire sizes needed. I always prefered to exceed recommendations. Lots of work, but when you can't come up with ready made.....

 

[Anonymous-0]

Some trades call DC power supplies rectifier although technically a rectifier is the device that actually rectifies the AC current also called a diode.
A 200 amp transformer would be expensive. The secondary is probably just copper bus material. Is the primary (220v side) shorted or open? I have rewound big transformers before and it is not too hard of a job if the transformer is on an open frame. You have to carefully unwind the windings and replace with the same gage and length of wire back with the same number of turns. Are you sure the problem is the transformer?
Click the link below for a company in Texas that rewinds transformers but I will tell you they are expensive.
Peter Dahl

 

[souNdguy]

sounds like you have a variac with a rectified output. A repair shop that specializes in electric motors may be able to help you out.

I have an electroplater.. but much less current.. i think mine is 20-25a.. etc.

soundguy

 

[Uncle]

It is an open type transformer, about 6 inches tall and 3 inches diameter. There are 4 in the enclosure. The transformer is shorted and it is easy to see where current has burned though the insulation on the windings.
I will continue the search but if all else fails, I will try to wind one.
Brian

 

[Anonymous-0]

that may be one of the easier rewinds. Are you saying there are 4 transformers? I am guessing that there is a switch that switches in the transformers for different voltages. I think you will have a hard time finding a new exact transformer but maybe some of the surplus sales have the exact or near exact transformer that might work. You would need the exact spec of each transformer to look for the correct part. Try searching for electro plating surplus sales.