Diode bridge rectifier replacement

[home4sale2]

Hi, new member, hope you guys can help. I have a Fahrenheat baseboard heater (LFP1652E) and I need to replace its diodge bridge. The numbers on the DB are SB254 and further search revealed that it might be 25A and 400 Volts (thus 254?). If I order it from a local store it's $40 but on other sites I can see it for $5 or less (rated at 25A and 400V). They look similar (physical size and pins) but the parts are 2504 or different numbers so I can't really cross reference. Questions:

1. Can I use a higher rated DB, I would think so but want to be sure (ex. can I use one rated at 50A and 1000V)? Does it give me additional protection against surges for ex?

2. Are there other specs that I should be looking for (beyond amps and volts)? I want to make sure I am comparing apples to apples and not cause a fire.

Thanks in advance.

 

[Hero999]

Yes of course you can use a higher rated part.

Volts and amps are the only important part of the specification as far as a rectifier is concerned.

What sort of case style is it?

Any >25A >400V rectifier in the same case style will do.

 

[home4sale2]

I don't know if I can paste links or not but here's a link to a pic that looks similar: **broken link removed**
I also found it on eBay here: **broken link removed**

It's about 1" x 1" x 1/3"...the arrangements of pins is similar to what I see in the pics except mine doesn't have a cutout notch on one of the edges (don't know if it's only meant to help me connect the wires or something like a processor that have a notch).

 

[Hero999]

Both look fine to me.

 

[home4sale2]

Thanks Hero, appreciate the help.

 

[HiTech]

It's about 1" x 1" x 1/3"...the arrangements of pins is similar to what I see in the pics except mine doesn't have a cutout notch on one of the edges (don't know if it's only meant to help me connect the wires or something like a processor that have a notch).

The chamfer or notched corner is nothing more than a visual identifier indicating the + output terminal. It may or may not have something to do with automated production during installation into large scale manufacturing. In your case, don't concern yourself with it. Just observe which wires attach to their respective terminal. applying some thermal paste between the diode base and the mounting surface as well as tightly securing it in place helps to transfer heat away from the bridge. Hopefully the mfgr. didn't screw it to a plastic case or something equally useless for transferring away heat!

 

[home4sale2]

The mounting surface is metal (case for a baseboard heater) and not near the heating element. Awaiting the arrival of 35A/600V (it's a 1500W heater, 110V with a 25A/400V rated rectifier). As for thermal paste, is that something I can get from home depot or a computer hardware store? I am thinking that brown goo that is used in PC's to dissipate heat using a heatsink/fan?

 

[HiTech]

Computer stores should have it although that stuff is pricey and a bit overkill for this app. Radio Shack should carry the cheaper stuff.