118
IM 738-2
Maintenance:
Control Panel Components
Control Panel Components
Manual Motor Protector (MMP)
The manual motor protector (MMP) provides coordinated
branch circuit, short circuit protection, a disconnecting means,
a motor controller, and coordinated motor overload protection.
A short circuit indicator with manual reset is mounted along
side of each MMP as a means to differentiate between a short
circuit and overload trip conditions.
The MMP trip points are factory set. Do not change unless the
motor ampacity changes or the MMP is replaced with a new
device with incorrect setpoint adjustment. Any other
non-authorized trip point or setpoint adjustment voids all or
portions of the unit’s warranty. Authorized setpoint adjustment
is accomplished as follows
1
For motors with a 1.15 service factor, rotate the arrow on
the dial to correspond to the motor FLA.
See
!
2
For motors with a 1.0 service factor, multiply the motor
FLA by 0.9; then rotate the arrow on the dial to correspond
to that value.
To reset a tripped MMP, clear the trip by rotating the knob
counterclockwise to the OFF position; then rotate knob
clockwise to the ON position. See
,
#
.
Other MMP features:
•
Three-position rotary operator: OFF-TRIP-ON
See
#
•
Lockout—tagoutable rotary operator: turn the rotary
operator to OFF, slide out the extension arm, and insert a
lockout pin.
•
Ambient compensated –20°F to +60°F
•
Single-phase sensitivity: if one phase exceeds setpoint, all
three phases open.
•
Trip test: insert a 9/64" screw driver in the slot to simulate a
trip. See
$
in Figure 120
.
Figure 120. Manual motor protector
Circuit Breaker
Circuit breakers are installed upstream of all VFDs to provide
short circuit protection.
To reset a tripped circuit breaker: Clear the trip by rotating the
lever down to the OFF position. See
!
in Figure 121. Then
rotate lever up to the ON position. See
#
in Figure 121.
Figure 121. Circuit breaker
WARNING
If an overload or a fault current interruption occurs, check
circuits to determine the cause of the interruption.
If a fault condition exits, examine the controller. If damaged,
replace it to reduce the risk of fire or electrical shock.
WARNING
If an overload or a fault current interruption occurs, check
circuits to determine the cause of the interruption.
If a fault condition exits, examine the controller. If damaged,
replace it to reduce the risk of fire or electrical shock.
Three-position
rotary operator
Trip test slot
3
Arrow
1
ON position
OFF position
1
2