Voltage measurement over the
cable
Put the device in test mode. When fT is displayed on the screen, disconnect the
relay board cables and measure the voltage. Touch the probe coming out of the
V
port of the measurement tool to the cable entering the terminal no. 4 of the
relay board, and touch the other end of the probe cable coming out of the
common (COM) port and the other three cables. Voltage values should be
b(21-26) VDC. If this value is not displayed even though the cables
are connected, replace the mainboard. If this value is -(21-26) VDC, the relay
trigger cable may be reversed. In this case, the relay board trigger cable must
be replaced. It will also damage the newly installed relay board and the
mainboard.
Measurement of relay contacts
1- Put the device in test mode. When fT is displayed on the screen, measure
the resistance between the relay contacts after you see that all the LED lamps
on the relay board are lit. There must be a short-circuit between the contacts.
2- Measure the resistance between the contacts when the relays are not
activated. The value should be open-circuit.
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