Mitsubishi Electric MS-T Series Instruction Manual page 26

(6) Prevention of foreign matter entering the display window
Note that the relay may not trip if foreign matter such as wire scraps enters the display window.
(7) Automatic resetting method
CAUTION
The unit is set to manual reset when shipped from the factory. This can be changed to automatic reset
by the user.
However, a stopper is provided at the switching plate to prevent the setting from being changed easily.
TH-T18
[Changeover procedures]
1. Remove the thermal overload relay's auxiliary terminal cover. (Fig. 1)
2. Cut off the stopper, and then press down on the reset bar and slide the switching plate (white) in the
direction of arrow X.
3. Mount the terminal cover, and confirm that the switching plate is at position A. (Fig. 3)
Fig. 1
TH-T25
1. Cut the reset bar's stopper section (shaded section) with a pair of nippers. (Fig. 4)
2. Using a Phillips screwdriver, press in the reset bar and turn it 90° counterclockwise (to position A).
Reset bar
Stopper
(Section to cut off)
Fig. 4
24
 Secure safety by assuming that accidents may occur due to automatic restarting
of the machine device, etc., when the output contact is recovered due to the
automatically-reset thermal overload relay, or when the power is recovered after a
power failure.
Manual reset
Switching plate
X
Fig. 2
Automatic reset
Fig. 3
Manual reset
Stopper
Reset bar
Automatic reset
Fig. 5