REPLACEMENT VOLTAGE REGULATOR FOR OLDER CATERPILLAR GENERATOR 1

[generatorman]

I have an older 80's vintage cat gen 446 frame 5n5060 that the original avr has quite working and most parts are obsolete to repair it and I was looking for aftermarket or OEM replacement. The tag reveals excitation at 22.7v and 9 amps with resistance of 2.4 ohms and I can't find an avr that goes that low in resistance. Basler has a few but still unsure if they will work. Thank you for your time!

 

[Ceast]

Cat should have a direct replacement reg for the VR3. Should be a VR6 or CDVR which are made by Basler. The CDVR is a damn fine piece. It's been my experience that the CAT replacement unit is less expensive than the Basler eqivalent unit. Hummmm

 

[catserveng]

The CAT VR6 is the direct replacement, it is a nominal 63 volt 12 amp regulator. The CAT VR6 is only available in 240 sensing.

The Basler AVC 63-12 is nearly indentical to the VR6, and available in three sensing ranges, 120, 240 and 480.

If you are using a droop transformer, you may find it doesn't work very well, best fix is to install a correctly sized 5 amp secondary CT, otherwise use the 1 amp CT input if you use the original CAT droop CT.

The CAT retrofit instructions are a bit confusing sometimes, the Basler manual available on line actually has all the info you need. Also the KATO K56-12B is the same regulator and the KATO manual is very good.

The CDVR is a very good regulator, but usually overkill for a standalone unit in the size you are working with. The CDVR is a custom CAT product built for CAT by Basler, it's features are between the DECS 100 and DECS 200 regulators. Also as a retrofit it is a little harder because you need to order the CAT wiring harness since CAT had it built with connectors and not terminals for wiring interface.

Hope that helps.

 

[generatorman]

does it matter with any of these regulators that my unit is not pmg based because most of these look to require pmg input?

 

[catserveng]

The CDVR and the VR6 can both be wired for SE (non PMG) applications, go to here at Basler for the VR6/AVC63-12 info, wiring connections on page 4.

http://www.basler.com/downloads/9337200991D.pdf

To use line power you will need a transformer to step down from your generator line voltage to the power input which is nominal 120 VAC, and has a power burden of about 1,200 VA.

CAT didn't make this an easy fix, as they have moved away from the traditional SE or PMG arrangements and newer small tail ends have AREP windings in the stator to supply the AVR power, just about all the larger units have PMG's.

Looks like Basler has dropped the 480 sensing version, KATO still has it I think, here is the link to the KATO manual,

http://www.kato-engineering.com/usermanuals/351-01057-00, K65-12B & K125-10B.pdf

There is also a company I ran into at PowerGen last year called McPherson Controls that has a lot of replacement voltage regulators for older generators, I used them for a regulator on an old CAT SRSE generator that CAT no longer had parts available for, their website is,

http://www.mtspowerproducts.com

Hope that helps