Mitsubishi Electric UM 5t Instruction Manual page 46

Problem
23. The overload alarm
does not function
properly.
24. The pushbutton will
not go down smoothly
or will not smoothly
pop up.
25. Pressing the DOWN
pushbutton lowers the
load, but pressing the
UP pushbutton also
lowers the load.
Cause
(1) The power supply line is not correctly
connected to the board.
(1) Foreign material caught by inner unit
(2) Defective inner unit
(1) Rotor slippage (The rotor is not properly
engaged with the motor shaft.)
- 42 -
Remedy
(1) Correctly connect the power
supply line. Connect "1"
and "S" to "A" and "B" on the
board.
(1) Check or repair.
(2) Replace.
(1) Replace.
* In this case, releasing the
pushbutton will
immediately stop the
lowering operation.