catarpilar VR 3F AVR

[themes1]

Dear friends,

this is VR3F Caterpillar AVR unit. can anyone say what is this black coulour part fixed here. i searched everywhere couldn't success. this part is not working.

 

[themes1]

it is having caterpillar 9Y8400 AVR

 

[catserveng]

It is the bridge rectifier. CAT did not supply repair parts for any of the VR3 series regualtors and this is an obsolete regualtor, the current replacment is a VR6, which is nearly identical to a Basler AVC63-12.

Mike L.

 

[themes1]

Thank you sir. in this part u can see 5 pins. 4 and 5 is working as a rectifier. 1 & 2 is reading in both way and 3 is not connected to any pin. someone told me 4 & 5 inside rectifier and 1,2,3 pins inside is a SCR.

that's y still i have a doubt. d u have a schematic diagram for this.

 

[catserveng]

Sorry, no internal schematic for a VR3, CAT never released one I know of, especially since they were pretty tight with anything that could affect parts sales. The technical specification for the VR3 says the field output is SCR controlled. But when working for the dealership going inside a sealed CAT box was a bad thing, so I can't help you much there.

The VR3 has been out of production for some time, as has the original manufacturer, so finding a replacment part may be a pain. If you are trying to save money and not buy a CAT replacement there are plenty of Chinese knockoff's out there at a much lower price.

Mike L.

 

[themes1]

Thank you very much. i found the solution for the problem of my avr. right now i am having 5 avr s to repair. i studied the circuit and i came to know it is a SCR with in side a diode. diode is ok and the problem is from scr. i bought a suitable scr from the market and fixed it separately. tested last night. .....thanks god it works..... still working and today i will repair the others. this avr is very good and giving problem from this avr or one high watt 2.5k resistor only. thanks again sir.