Brochure

PowerPact H-, J-, and L-Frame Circuit Breakers
Motor Circuit Protection
57
02/2016
© 2011–2016 Schneider Electric
All Rights Reserved
Trip Class
• The class is selected as a function of the normal motor starting time.
— Class 5: starting time less than 5 s
— Class 10: starting time less than 10 s
— Class 20: starting time less than 20 s
• For a given class, it is necessary to check that all motor-feeder components are sized to carry the
6 x FLA starting current without excessive temperature rise during the time corresponding to the
class.
Short-Circuits
Short-time protection (I
sd
)
• Provides protection with an adjustable pick-up I
sd
.
• There is a very short delay to let through motor starting currents.
Non-adjustable instantaneous protection (l
i
)
• Instantaneous protection with non-adjustable pick-up l
i
.
Phase Unbalance or Phase Loss (l
unbal
)
• This function opens the circuit breaker if a phase unbalance occurs:
— that is greater than the 30% fixed pick-up I
unbal
— following the non-adjustable time delay t
unbal
equal to:
• 0.7 s during starting
• 4 s during normal operation
• Phase loss is an extreme case of phase unbalance and leads to tripping under the same
conditions.
Indications
Front indications
• The green “Ready” LED blinks slowly when the electronic trip unit is ready to provide protection. It
indicates the trip unit is operating correctly.
• Red alarm LED for motor operation goes ON when the thermal image of the rotor and stator is
greater than 95% of the permissible temperature rise.
Remote indications using SDTAM module
• PowerPact H-, J-, and L-frame devices with a Micrologic 2 M trip unit can be equipped with an
SDTAM module dedicated to motor applications for:
— A contact to indicate circuit-breaker overload.
— A contact to open the contactor. In the event of a phase unbalance or overload, this output is
activated 400 ms before circuit-breaker tripping to open the contactor and avoid circuit breaker
tripping
• This module takes the place of the shunt trip (MN)/undervoltage trip (MX) coils and an auxiliary
switch (OF) contact
SDTAM remote indication relay module with its terminal block.
Note: All the trip units have a transparent sealable cover that protects access to the adjustment rotary
switches.