CHAPTER 4: ACTUAL VALUES
A2 Metering
Current
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
Courtesy of NationalSwitchgear.com
The relay measures all RMS currents and voltages, frequency, and all auxiliary analog
inputs. Other values like neutral current, symmetrical components, power factor, power
(real, reactive, apparent), are derived. All quantities are recalculated every power system
cycle and perform protection and monitoring functions. Displayed metered quantities are
updated approximately three (3) times a second for readability. All phasors and
symmetrical components are referenced to the A-N voltage phasor for wye-connected
VTs; to the A-B voltage phasor for delta connected VTs; or to the phase A current phasor
when no voltage signals are present.
By scrolling the Up/Down keys the relay shows one-by-one, all metered values as follows:
PH A CURRENT
o
0.0 A 0
lag
Range: 0.0 to 30000 A, 0 to 359
PH B CURRENT
o
0.0 A 0
lag
Range: 0.0 to 30000 A, 0 to 359
PH C CURRENT
o
0.0 A 0
lag
Range: 0.0 to 30000 A, 0 to 359
NTRL CURRENT
o
0.0 A 0
lag
Range: 0.0 to 30000 A, 0 to 359
GND CURRENT
o
0.0 A 0
lag
Range: 0.0 to 30000 A, 0 to 359
GND CURRENT is shown when the GROUND CT TYPE is set to "1A Secondary" or "5A
Secondary".
SENS GND CURRENT
o
0.00 A 0
lag
Range: 0.00 to 15.00 A, 0 to 359
SENS GND CURRENT is shown when the GROUND CT TYPE is set to "50:0.025".
o
lag
o
lag
o
lag
o
lag
o
lag
o
lag
A2 METERING
4–7