Replacing a Solid State Rectifier

[Perkinsman]

This is the first time I've replaced a solid state rectifier and I don't want to screw it up. The existing is a S15VB rectifier and from what I've read the replacement is an NTE5313. I found one at the store but it is significantly smaller. Does anyone know if it is the correct replacement?

[TelRay]

Hi Perkinsman,

I believe that for the guys higher up it would be good to know a bit more about the application the rectifier is being used at. Sometimes instead of just replacing for an equivalent part you could end up upgrading a component for just a few cents more. Giving the full picture might help to give you the proper recommendations.

I believe the reference you have provided is lacking two digits at the end that might help dimension the right rectifier for you.

For instance, I have found an SV15VB60 at Mouser (currently our of stock) https://www.mouser.com/ProductDetail...xr1VwgCg%3D%3D

Also seen on the datasheed values raging from the SV15VB10 to SV15B100 https://www.alldatasheet.com/view_da...age=2&sField=0

[nevetslab]

I looked up the part, and it appears to be a ShinDengen 4-terminal molded Bridge Rectifier....15A 600V, though it doesn't appear to be rated in a High Speed application. Just to be clear, is this a square molded package, mounted with a machine screw/nut/washer thru the center, with four 1/4" Fast-on terminals, connected with either quick-disconnects or leads directly soldered to the terminals? What's the product it's installed in? Have you already measured the bridge rectifier sections and determined any/all of the four diode sections are shorted (or open).? There are multiple mfgrs parts that would be suitable as a replacement, if this is a S15VB60 bridge rectifier. I downloaded this data sheet for clarification:

S15VB60-1863545.pdf

[Perkinsman]

You guys are so good at what you do, I appreciate you! I spoke to the Mouser tech and put the order in earlier today but after reading your message, I just checked the datasheet, it's 29mm square but I told the tech 26mm, so they sent the wrong part: Mouser #12-GBPC1506.

[Enzo]

Wrong? 15A 600v sounds like just what you are looking for. Doesn't matter if the exterior is a millimetre or two different size.

[Perkinsman]

I thought the size had to be exact but Enzo’s correct, the space will accept up to 31.75mm square. I’m hoping that’s all it needs!

[nevetslab]

While we've steered you to a suitable replacement Bridge Rectifier, you haven't yet told us what you found on the existing bridge, such as one or more of the diodes within the epoxy block being shorted, and what this Bridge is installed in......no doubt an amplifier, but.....when a bridge fails, there's often a cause for it, such as shorted power supply filter cap or shorted amp assembly with no means of circuit protection following the bridge, and perhaps AC mains protection circuit (fuse, ckt breaker) didn't open, or wrong fuse value......etc.

[Perkinsman]

This is a Concept 11.0 receiver. It came to me without a fuse or fuse cap, told me that it only had one channel working and then one day just starting smoking and blew the fuse. The reason I think the rectifier is bad is because the area above it on the metal case has a burn shadow all around the rectifier. I did the multiple tests with diode mode of the DMM and one of the tests indicated with an OL when it should have been showing a drop of .4-.7v. It's coming in tomorrow and after I replace it and the 8 amp fuse, I'll bring it up on the dim bulb tester and check back in.

[Perkinsman]

I wanted to update this post since I installed the new rectifier. I ordered and received a 20mm 8A fuse rather than a 30mm so I'll need to wait for those to come in. Is there a problem using a slightly smaller fuse, like a 6A to at least see whether it will start up?

[The Dude]

That shouldn't be an issue for testing. It certainly won't hurt anything. There will be a startup surge, but it shouldn't reach 6A. If you have a variac, bring it up slowly.

[Perkinsman]

It didn't power up...argh...i'm hoping it's the switch and not the transformer. In order to test the tranny, does each primary and secondary have to be removed?

[nevetslab]

It didn't power up...argh...i'm hoping it's the switch and not the transformer. In order to test the tranny, does each primary and secondary have to be removed?

You'll need to disconnect the Secondary winding connections to the circuits, which will unload the xfmr. Leave the primary connected. I'm assuming there are more than one secondary winding...those that go to this 16A Bridge Rectifier, and the associated CenterTap, if there is one. I haven't googled your product to see what it is. It could be the circuits that follow the output connections from the bridge rectifier.

[Jazz P Bass]

"Is there a problem using a slightly smaller fuse, like a 6A to at least see whether it will start up?"
The factory 8 amp mains fuse was selected for the power draw of the amplifier pushing 100 watts into an 8 ohm stereo load. (175 watts into a 4 ohm load)
At idle, the amp should not even draw 1 amp.

[Perkinsman]

You'll need to disconnect the Secondary winding connections to the circuits, which will unload the xfmr. Leave the primary connected. I'm assuming there are more than one secondary winding...those that go to this 16A Bridge Rectifier, and the associated CenterTap, if there is one. I haven't googled your product to see what it is. It could be the circuits that follow the output connections from the bridge rectifier.

I've never tested a transfomer before so I'll need some guidance here. On the primary side (closest to AC cord) there are 2 white wires, 1 orange, 1 blue & 1 yellow. On the secondary side there are 2 red wires, 2 green wires & 1 brown wire. Which ones do I measure resistance between and what values should I expect if it is good?

[nevetslab]

Assuming you don't have the means of measuring AC Mains current, we're just looking to see if the transformer by itself has an internal short (drawing loads of current). if you have a Light Bulb Limiter, use it. With the secondary wires disconnected, so there's NO LOAD on the xfmr, it should draw very little current. The LIght Bulb Limiter wouldn't glow. I'm guessing the two GRN wires are one winding, the two RED wires a separate winging, and perhaps the BRN wire a C/T between the RED wires, though we'll find out. With your DMM, set it to OHMS, lowest range. If it has the ability to NULL the lead wires, short them and NULL, so you get zero ohms. If not, no big deal. Measure between the two RED Wires. If you get a resistance reading, it will be low, typically. And,if you do, see if there's resistance reading between either RED wire and the BRN wire. If no, then measure between the two GRN wires. If you get resistance, it will also be low, typically. See if there's any resistance between them and the RED wires. Then see if the BRN wire has resistance between it and the GRN wires.

If the transformer works, there will be AC voltage between the two RED wires, half that voltage if the BRN wire is a C/T to the RED wires. There should be AC voltage between the two GRN wires, and if BRN is a C/T to the GRN wires, you'd see half that voltage between the GRN and BRN wire. Position the wires so they don't short to each other or the chassis. Of course, it could be that the windings are RED & GRN instead. DMM will point the way.

For measuring the AC Voltage on the Secondary windings, start with the highest range, as if there is a tube circuit, you'd have much higher AC voltage than if it's all Solid State.