December 2021
Service Manual
MDE 252 Rev. 1
Troubleshooting
24
Section 2: Troubleshooting
2.6
The Actuator Does Not Work with
Remote Controls
1.
Move the 3-position selector to LOCAL and check that the actuator works with
local controls.
2.
Move the local selector to REMOTE. If the ESD signal is active, the alphanumeric
display indicates "ESD ON". Check the signal on terminals C3 and C4 and adjust
the ESD configuration. If the alphanumeric display indicates "INT", an interlock
control is present. Check the signal on terminals B3, B4 and B5, and adjust
Interlocks configuration.
3.
Check that:
a.
The wiring to terminals B1-B2 and C1 is correct.
b.
There is no short-circuit between wires.
c.
The electrical load does not exceed 4 W.
d.
If external voltage supply is used check that the value is in the range
20-120 V AC 50/60 Hz or 20-125 V DC.
2.7
The Motor is Very Hot and Does Not Start
1.
Check that no alarm other than motor overheating is present.
2.
Wait until the motor cools down and the normally closed contact of the thermal
switch automatically resets before trying to operate the actuator again.
3.
Check that the number of operations per hour and their duration is suitable for the
actuator service (see the nameplate menu).
4.
Check that the valve operating torque is within the range of the unit’s designed
operating torque.
5.
Check current absorbed and compare con the value stated by nameplate.
