MPC2000D Issue 2 22/4/98 Page 5
3.1.5. Thermistor/RTD Inputs
Time Delay: 0.5 +/- 0.2 seconds
Thermistors
Range: 0.1 - 30 Kilo-Ohms
Accuracy: +/- 0.1 Kilo-Ohm up to 5 Kilo-Ohm
+/- 3% above 5 Kilo-Ohm
RTD's
Range: 100 to 240 Ohms
Accuracy: +/- 3%
Max. Wire Resistance: 25 Ohms
3.1.6. Overload Alarm and Trip Curves
Fault Time Accuracy: +/- 1 second up to 10 seconds
+/- 1 second +/- 2% above 10 seconds
Threshold Current Level: Overload Setting +/- 1.5%
3.1.7. Current Unbalance Alarm and Trip
Method: Unbalance = 100 x (Imax - Imin) / Ir %
Where Imax = max. of 3 phase currents
Imin = min. of 3 phase currents
Ir = Larger of Imax or Motor FLC
Alarm
Threshold Unbalance Level: 50% of Unbalance current +/- 2%
Fixed Time Delay Accuracy: 1.0 +/- 0.5 seconds
Trip Curves
Threshold Unbalance Level: Unbalance Current Setting +/- 2%
Trip Time Accuracy: +/- 1 second up to 10 seconds
+/- 1 second +/- 2% above 10 sec.
3.1.8. Fault Time Delays
Accuracy: +/- 0.5 seconds or +/- 2% of time
Exceptions
High Set Over-current: -0.1 to +0.2 sec. up to 1 second
Earth Fault Trip: -0.1 to +0.2 sec. for less than
1 second delayTotal Run Time
Accuracy: +/- 2%