12
Volts reading = (27245 – 0)
(17,280 - 0)/(32767 – 0) + 0 = 14,368V
2. Current readings
Assume device settings: CT primary current = 200A.
Current engineering scales (see Section 4):
ENG_HI = Imax = CT primary current
2 = 200.00
2 = 400.00A
ENG_LO = 0A
If the raw data reading is 819 then the current reading in engineering units will be as follows:
Amps reading = (819 – 0)
(400.00 - 0)/(32767 - 0) + 0 = 10.00A
3. Power readings
a) Assume device settings (direct wiring): Wiring 4LL3; PT = 1; CT primary current = 200A; Voltage
scale = 828V.
Active Power engineering scales (see Section 4):
ENG_HI = Pmax = Vmax
Imax
2 = (828.0
1)
(200.00
2)
2 = 662,400W = 662.400kW
ENG_LO = -Pmax = -662.400kW
If the raw data reading is 18024 then the power reading in engineering units will be as follows:
Watts reading = (18024 - (-32768))
(662.400 - (-662.400))/(32767 –(-32768)) +
(-662.400) = 364.368kW
If the raw data reading is -500 then the power reading in engineering units will be as follows:
Watts reading = (-500 - (-32768))
(662.400 - (-662.400))/(32767 – (-32768)) + (-662.400) =
-10.097kW
b) Assume device settings (wiring via PT): Wiring 4LN3; PT = 120; CT primary current = 200A;
Voltage scale = 144V.
Active Power engineering scales (see Section 4):
ENG_HI = Pmax = Vmax
Imax
3 = (144
120)
(200.00
2)
3/1000 = 20,736kW
ENG_LO = -Pmax = -20,736kW
If the raw data reading is 12000 then the power reading in engineering units will be as follows:
Watts reading = (12000 - (-32768))
(20,736 - (-20,736))/(32767 – (-32768)) +
(-20,736) = 7,594kW
If the raw data reading is -5000 then the power reading in engineering units will be as follows:
Watts reading = (-5000 - (-32768))
(20,736 - (-20,736))/(32767 – (-32768)) +
(-20,736) = -3,164kW
4. Power Factor readings
Power factor engineering scales (see Section 4):
ENG_HI = 1.000.
ENG_LO = -1.000.
If the raw data reading is 29166 then the power factor in engineering units will be as follows:
Power factor reading = (29166 - (-32768))
(1.000 - (-1.000))/(32767 –(-32768)) +
(-1.000) = 0.89
