Power System Measurements
HV line measurements on all three phases are made as follows:
| Parameter | Value |
|---|---|
| Voltage Range (RMS Phase/Earth) U27/UR27/E27 | 2...15 kV |
| Voltage Range (RMS Phase/Earth) W | 2...24 kV |
| Voltage Range (RMS Phase/Earth) RL15/RL27 | 2…15 kV |
| Voltage Range (RMS Phase/Earth) RL38 | 2…22 kV |
| Voltage Resolution | 1 V |
| Voltage Accuracy(1) | 2.5% ± 25 V |
| Live Terminal Threshold Voltage range(2) | 2...15 kV |
| Live Terminal Threshold Voltage setting resolution | 1 V |
| Live Terminal Threshold Voltage accuracy(1) | 5% ± 250 V |
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Ratings and Specifications |
|
| Live terminal threshold hysteresis | -20% |
| Phase current range (true RMS) |
1.5...800 A |
| Earth current range (true RMS) | 1...800 A |
| Current resolution | 1 A |
| Phase current accuracy(1) |
± 1.0% ± 1 A over range 10...800 A |
| Earth current accuracy(1) |
± 1.0% ± 1 A over range 10...800 A |
| Apparent power range |
0...36 MVA: PMSet U Series |
| Apparent power resolution |
1 kVA |
| Apparent power accuracy(1) |
± 3% over range 20...800 A |
| Real power range(3)(4) |
-36...+36 MW: PMSet U Series |
| Real power accuracy(1) |
± 3% at (Power Factor) PF> 0.9 |
| Real power resolution | 1 kVA |
| Reactive Power Range |
0...36 MVAR: PMSet U Series |
| Reactive power Resolution |
1 kVAR |
| Reactive power accuracy(1) | ± 4% at PF = 0.5 |
| Unsigned PF | 0.0...1.0 |
| PF resolution | 0.01 |
| PF accuracy | ± 0.05 |
| Measurement filter time constant (step response) | 2 s |
| Measurement update rate | 0.5 s |
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(1) Includes accuracy of switchgear CT and VTs. (2) Used for live/dead display, live load blocking and loss of supply detection. (3) In database for transmission by a protocol. (4) Used to accumulate kWh reading for weekly maximum demand data. |
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