Siemens FS-250 Bridge Rectifier

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jm2014
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Siemens FS-250 Bridge Rectifier

Post by jm2014 » Sat Dec 30, 2017 2:15 pm

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.

Thanks!

jm2014
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Re: Siemens FS-250 Bridge Rectifier

Post by jm2014 » Sat Dec 30, 2017 2:18 pm

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.

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Re: Siemens FS-250 Bridge Rectifier

Post by Old fire alarm guy » Wed Jan 03, 2018 1:06 pm

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:
http://www.firealarmsonline.com/2013/05 ... ifier.html
I've forgotten more than I remember.

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Re: Siemens FS-250 Bridge Rectifier

Post by Retired STR-SG » Wed Jan 03, 2018 2:40 pm

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.

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Re: Siemens FS-250 Bridge Rectifier

Post by jm2014 » Mon Jan 08, 2018 3:17 pm

Retired STR-SG wrote: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?

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Re: Siemens FS-250 Bridge Rectifier

Post by Retired STR-SG » Mon Jan 08, 2018 3:35 pm

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. https://www.twistywristarcade.com/92-molex-connectors They can also be found on Ebay.

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