Troubleshooting; Auxiliary Switch Does Not Work; Fail-Safe Does Not Work; Feedback Does Not Work - KMC Controls MEP-4 Series Application Manual

Troubleshooting

Auxiliary Switch Does Not Work

• Check the auxiliary switch setting. See
Switch (MEP-4x2x/4x7x) on page
• Check the wiring. (See
10.)

Fail-Safe Does Not Work

• After initial connection or reconnection to power
on MEP-42x2/45x2/49x2 proportional models,
proper fail-safe operation might be delayed
up to 30 seconds (until the capacitors are fully
charged).
• Check the Fail-Safe Direction switch. See
Safe Direction (MEP-42/45/49xx) on page

Feedback Does Not Work

• Check the feedback switch setting. See
tional (MEP-4xx2) Models Setup on page
• Check the wiring. (See
10.)

No Rotation

• After initial power-up, proportional fail-safe
MEP-42x2/45x2/49x2 actuators delay enabling
motor operation until the fail-safe capacitors are
charged. No actuator rotation will take place for
at least the first 30 seconds.
• Check that direction switches are fully engaged
in the proper position. See
(MEP-4xx2) Models Setup on page 10
Tri-State/2-Position Rotation Direction on page
11.
MEP-4xxx Direct-Coupled Actuators (40 to 90 in-lb.)
Auxiliary
12.
Wiring Issues on page
Fail-
13.
Propor-
10.
Wiring Issues on page
Proportional
and
• Check that the shaft moves freely. (Press and
hold the gear disengagement lever and manually
rotate the shaft.)
• Check for a tripped circuit breaker to the trans-
former (or power supply).
• Check polarity and strength of input signal.
• Check for proper supply voltage from the trans-
former (or power supply) and that it has enough
capacity (VA) for all connected devices. See their
respective data sheets and
24-Volt Power Application Note
• Check the wiring. (See
10.)

Rotation in Wrong Direction

• For proportional models, check the position of
the direction switch (Switch 2). See
(MEP-4xx2) Models Setup on page
• For tri-state and tri-state/two-position mod-
els, check the CW/CCW wiring and rotation
direction switch if applicable. See
Position Rotation Direction on page
• For fail-safe operation, check the Fail-Safe
Direction switch. See
42/45/49xx) on page

Stroke Range Is Wrong

• For proportional models, check the auto-
mapping. See Proportional (MEP-4xx2) Models
Setup on page 10.
• Check the adjustable stop.
• Check the voltage from the controller or thermo-
stat.
9
Tips for Connecting
(AN0604D).
Wiring Issues on page
Proportional
10.
Tri-State/2-
11.
Fail-Safe Direction (MEP-
13.
Applications Guide, AN0513A Rev. J