Specs Needed For SCR

[dnpainting]

Hi,
I am looking for the specs and or replacement suggestion for an SCR. This is for a Baldor BC154 (KB Electronics Manufactured it) DC Motor Control Unit that I purchased. The SCR # is A69258. I have 3 books I've looked thru and searched the web, but came up empty. Thank you for any help.

David

 

[SolderIron]

Knowing the current and voltage on the motor will help. I assume it plugs in the wall socket??

 

[dnpainting]

Here are the specs on the Control Unit:

The motor itself is a 115v, 15.5amp DC

Here is a link for the manual:
http://www.baldor.com/support/Literature/Load.ashx/MN705?ManNumber=MN705

Thank you

 

[SolderIron]

Don’t have the circuit diagram. I am guessing the armature volt is varied to change speed. You may have a Triac instead of SCR. Table 1-5 can be a basis to guess at the semi conductor. If you are using 220 vac, Device PIV > 2 x 1.42 x 230 volt. I > 20A.
110vac, Device PIV > 2 x 1.42 x 120 volt. I > 20A

 

[d3imlay]

SCRs/triacs don't fail very often. Is it shorted?

 

[dnpainting]

On the circuit board, it is labeled as SCR. I have a schematic of an older board for the same controller, I just have to get it printed as PDF and will post it. The one I removed shows a short across all pins. I need to make a tester with a bulb to really test it.

On the older Schematic it is listed as SCR, Parts list says "Power SCR S8015L" but thats the older one.

 

[dnpainting]

I've also found a place that carries the replacements but at $17.00 a piece, I was hoping to get them for cheaper thru Mouser.
http://penta-power.industrialpartner.com/products-a/a69258.htm

Now they don't have the price even listed

 

[dnpainting]

One other thing, I believe who ever had this before put 220vac input when setup for 110vac. There was some black arching across the AC input terminal. Also, the fuse was removed from unit.

 

[dnpainting]

Partial Schematic.

 

[dnpainting]

The specs on S8015L: Older Board

 

[dnpainting]

Well, I got a reply back from "Littelfuse", the company that acquired Teccor, maker of the A69258.

Here is their reply:
"Hi David,
Thanks your inquiry.
But sorry that the A69258 is a customized device and we cannot disclose any information without an LOA(Letter of Authorization). If you just want to repair your products, please try our standard part S8025LTP, although they have some differences. Thanks."

I guess that is what I will do.

 

[SolderIron]

Schematic is missing lines and therefore incomplete. Guessing with the missing lines, the 2 SCRs and diodes makes a full wave phase angle variable turn on. Load being inductive, I would use the #4 estimates to select the replacement.

 

[dnpainting]

Well, there was a broken trace coming off the AC input. I put the SCR back in and jumped the AC line to the next connector and the unit works but I have no control of the DC voltage via potentiometer. I have a constant 110vdc coming out. I sent email to KB electronics and they replied they don't share schematics.

Thank you all for your help, I may just sent it in to get repaired by KB.

 

[Guest106]

Hope this is allowed.
I am not affiliated with nor have I ever purchased parts from these people.

http://www.galco.com/scripts/cgiip.exe/wa/wcat/itemdtl.htm?pnum=A69258-NBR

$3.59 each.

 

[dnpainting]

Thank you for the link Pcbmann. I did order from another source here in So. Cal. that said they were in stock. They sent me the shipment link and it is coming from China, :sigh:. They did not specify that's where it was coming from when I ordered.

 

[d3imlay]

be very leery of the china part. There is a lot of counterfeit parts out there.This appears to be a generic application. If in doubt get one from Mouser. 40A, 600V should be adequate. Assuming it's mounted on a heat sink make sure to use a small amount of of heat sink gresae

 

[dnpainting]

Thanks d3, I know about the China Parts. The guy that sold the unit to me off ebay sent me another unit. Between the 2 of them, I can hopefully get one going.

 

[dnpainting]

Between the 2 Baldor units I now have a working one. Thank you all for your input and help. Now to get it mounted along with the Leeson DC motor for my lathe.