Siemens FS-250 Bridge Rectifier

So, I managed to snag a FS-250 Panel for a very cheap price! The only problem is it’s missing the bridge rectifier. I don’t believe the unit can power up without that. Unfortunately there is no FS-250 bridge rectifier on the market right now. If I were to buy a similar bridge rectifier and connect it to the pin connector that motherboard takes will that work? I have the installation manual so I know which order the wires would connect to the pins. I want to see if anyone knows that will work before I go out and buy it.

Also the unit doesn’t power up if I connect the batteries itself, however some panels will not power up on batteries unless AC voltage is present. I would have to see if the rectifier works before it’s considered junk.


I forgot to mention when I plug it in, I hear the board doing the 60hz buzz but nothing powers up. So the board at least partially works.

I’m not sure if the rectifier is anything special on those panels. One of the companies I used to work for a ways back used them alot on AC transformers to convert to 24VDC for door holders, etc.

This link might help:

Old fire alarm guy is correct that there is nothing magic about the factory installed bridge rectifier. Most manufacturers use a hefty bridge rectifier rated for 3 or 4 times the expected current needs. That makes a good safety factor for surges and bridges are not expensive. Find a 100 volt 20 or 30 amp bridge and it will work. If you do not have the harness it will take some detective work to determine the connections.

I have the wiring diagram for the bridge rectifier and harness colors. The problem now is finding the Molex connector for it. It’s 4 pin and evenly spread out, nothing weird, is there any wire harnesses already pre-made with that type of connector?

You can Google Molex to find their web site to look at the catalog to match up what you need. The connectors and pins are available at Mouser, Digi-key, and even this pin ball repair web site. Molex Connectors They can also be found on Ebay.