GE AKR-30 Series Maintenance Manual page 160

SECTION 1 4-MicroVersaTrip® Plus and M icroVersaTrip® PM Tri p Units
1 4.8 TRIP U N IT FUNCTIONS
M icroVersaTri p® P l us and M icroVersaTrip® PM tri p units
have specific standard and o ptional fu nctions. All trip
u nits share a series of i nterchangeable rating plugs. The
standard functions for both types of trip unit are as
follows:
•
Protection
- Long-time protection
- Instantaneous protection
•
Status
- Tri p target
•
Metering display
- Phase c urrent (selectable among phases)
The optional functions available on both types of trip
u n it are as follows:
•
Adjustable protection
- Switchable i nstantaneous and g round-fault
protection
- High-range (fixed) i nstantaneous overcurrent
protection
- Short-time protection, with or without I 2T
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- G round-fault protection, with or without 1 2T
- Zone-selective i nterlock, with grou nd fault only
or with both g round fault and short time
Add itional optional functions available only with PM
style trip u nits are as follows. PM style trip u n its requ i re
the presence of external control power.
•
Configurations
- Communication and metering
- Communication and protective relaying
- Communication, meterin g , and protective relaying
•
Metering and protective-relaying functions
- Voltage
- Energy (kWh/MWh)
- Real power (kW/MW)
- Total power (kV AIM VA)
- Frequency (Hz)
- Protective relays (undervoltage, overvoltage,
voltage un balance, current u n balance, and
power reversal)