[alain aleman]

Hi,
I need all varistors code for change, please. The first for right position is fire and i can´t read the correct numbers.
Regards,
Alain

[john-100]

as no one with a HAAS TL_3 has replied

do you have the maintenance manual with the circuit diagrams showing the connections to the varistors ??


going by your photo it looks like you have
EPCOS S20 K250 in positions VR1 & VR4
and what looks like
S20 K460 in positions VR2 , VR3, VR5 and VR6

PDF EPCOS data sheet :-

Attachment 379446

after a quick web search
in the UK , http://uk.farnell.com has them

http://uk.farnell.com/epcos/b72220s0...ngdom%2Fsearch

in the US
Mouser Electronics
https://www2.mouser.com/Search/Refin...yword=s20+k460

John

[alain aleman]

Thank you so mucho my friend, is correct.
Regards,
Alain

[alain aleman]

Hi John,
I was looking the board and the order varistor is not the same. Attached the diagram.

[john-100]

Hi Alain

obviously the photo did not show me enough detail !!!


I have had a look at the HAAS web site but they don't appear to make the circuit details of the PCB's available


assuming no other damage has been done ( like fuses or PCB tracks blown )

I would expect you will measure about

230 to 240 V AC across the S20 K250 varistors

and 420 to 440V AC across the S20 K460 varistors

so you should be able to workout what device was destroyed

by measuring across the PCB terminals


the S20 indicates the varistor's diameter

and the 3 digits after the K is the Max. AC operating voltage


what does the under side of the burnt terminals look like ??

be care full removing the wire ends not to pull out the Via's (plated through holes)
or peel the copper tracks of the board



John