[voytek1]

Surge suppressor circuit board 1170-2 contains three varistors.
Which of them is correct for 240-250 volts power supply line:
NTE524V15 or NTE524V25 ?
Can anyone answer?

[john-100]

it could be a mixture of both varistors

if you have just the L1 , L2 and Neutral connections from a transformer like this





you can use a NTE524V15 if its connected between L1 and Neutral or L2 and Neutral

Attachment 404858


you will need to use a NTE524V25 if its connected between L1 and L2

Attachment 404860


while you could trace the connections on the board but
a simple solution without the maintenance manual will be to measure the voltage across the varistor terminals on the board

if the voltage its about 120V use a NTE524V15

if the voltage its about 240V use a NTE524V25

John


PS
found this photo on line

Attachment 404874

its not clear what the 3 screw terminals are but I expect its going to be like this



PPS
if you connected the board to a 3 phase supply with 245 to 250V between phases
like this

Attachment 404878

you will need to use six NTE524V25

[voytek1]

Thanks John-100

[ASIGuy]

Voytec1,

If you don't want to fuss with finding the MOV's, soldering and such, we have the boards in stock ready to plug in.

PCB-0146 (PCB: 510V SURGE SUPPRESSOR; 1170-2\N): $85
PCB-0145 (PCB: 250V SURGE SUPPRESSOR; 1170-2): $90
Both in stock

FadalCNC Tech Support.