172-65316M-08 (MB12A/MB12AF/MB12B/MB12BF) 7 Oct 2021
23
Actuator Unit
Problem
Cause
Remedy
Does not operate
even though control
switch is operating
Actuator is broken
(manual operation is possible, see
p. 12 for manual operation
instructions)
Contact TLV
Improper wiring or control
Correct the problem
Power is not reaching the unit or
the voltage is incorrect (also check
current and fuses)
Correct the problem
Thermal protector is not functioning After allowing the thermal protector
to cool down, begin its operation
again and re-check to ascertain
whether operation of the thermal
protector is the cause
Check the voltage between
terminals T1 and T3 and between
T2 and T3
•
When the valve should be open,
power should be supplied to T1
and T3
•
When the valve should be
closed, power should be
supplied to T2 and T3
Correct the problem
Does not rotate the
full 90°, stops at a
partial rotation
There is a problem with the control
system
Correct the problem
If the above remedies do not restore the equipment to normal operation, make a note of
the operating pressure, operating temperature, frequency of operation, and serial number
of the product, and then contact your sales representative.
In the event of product failure, any necessary repairs shall be carried out by TLV, so do
not disassemble the actuator unit.
