Veichi AC310 Service Manual page 20

(RCE level changes from high to low, the main relay is disconnected), when
undervoltage, the signal source from CPU changes from low level to high level (5V).
After normal power-on, check whether the primary side of the optocoupler is about
0.5V, and whether the secondary side and COM voltage is 24V, if both are normal, then
consider whether the relay is damaged.
Measure the resistance value, if there is resistance value and the same as the silkscreen
value, the resistance is normal, if different and infinity, it means burned out, replace it.
Put the relay into DC24V, when it is good, the coil will absorb, and the multimeter
will measure that the coil is on. Relay is good. Measurement does not conduct, the relay is
damaged
4. Damage-prone devices
Optocouplers, transistors
5. Device bit number and specification
Resistance
R6=300Ω/0805 R141=5.1K/0805
R110/R11=10K/0805
Optocoupler
O10=EL2501S(K)
AC310 Universal AC Drive Service Manual
Capacitance
C1/c114=100nf/0805
Triode
Q110=MMBT4401LF1
Relay
SQM:6W150RJ
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