KRB-5404
9
2-3. Installation Precautions
CAUTION
Electrical work must be done by competent persons.
Do not place the ACB in such an area that is subject to high temperatures, high humidity, dusty air, corrosive gases, strong
vibration and shock, or other unusual conditions. Mounting the ACB in such an area could cause a fire or malfunction.
Be careful to prevent foreign objects (such as debris, concrete powder, dust, chippings, and iron powder) and oil or rainwater
from entering the ACB. These materials inside the ACB could cause a fire or malfunction.
Prior to commencing any work on the ACB, open an upstream circuit breaker or the like to isolate all sources of
power/voltage. Otherwise, electric shock may result.
Fix the draw-out cradle of the ACB firmly on a flat, level surface using mounting screws. Otherwise, the draw-out operation
may cause the breaker body or the draw-out cradle to fall, resulting in damage to the ACB or personal injury.
Take care not to deform or bend protrusions in the bottom face of the draw-out cradle when fixing the draw-out cradle with
mounting screws. Deformation of the protrusions may cause a malfunction (see Fig. 4).
Connect conductors (including screws) to the main circuit terminals in the specified area. Otherwise, a short-circuit may
result.
When terminating conductors to the ACB, tighten terminal screws to the torque specified in this manual. Otherwise, a fire
could result.
For 4-pole ACBs, be sure to connect a 3-phase, 4-wire neutral conductor to the N-phase pole (on the right end). Otherwise, an
overcurrent may hinder the ACB from tripping, resulting in a fire.
Fig. 4 Protrusion on the bottom of the draw-out cradle
For AR440SB, the mounting screw protection covers are installed on two of four mounting screw holes. When fixing the draw-
out cradle, insert the draw-out cradle mounting screws into these two holes while lifting open the covers.
Do not lift open the cover too high. Failure to do so may result in damage to the cover.
(When lifting open the
mounting screw protection cover)
Fig. 5 Mounting screw protection cover
Draw-out cradle mounting screws
Hex head M12 (4) (not supplied)
with spring washer, flat washers (2)
and nut
Tightening torque: 41 - 52 N·m
Protrusion
Draw-out cradle
mounting screw hole
Mounting screw
protection cover
Protrusion
Draw-out cradle
mounting screw hole
