Rockwell Automation 825-P Modular Protection System for Motors User Manual - Manual (Page 154)

154 Rockwell Automation Publication 825-UM004D-EN-P - November 2012
Chapter 11 Testing & Troubleshooting
Delta-Connected Voltages
Perform the following steps to test delta-connected voltages:
1. Connect the current source to the MCM module, as shown in Figure 50
on page 151.
2. Connect the voltage source to the 825-P, as shown in Figure 52. Make sure
that Xfmr Connection=Delta.
Figure 52 - Delta Voltage Source Connections
3. Use the front panel SET/SHOW or MPS Explorer software to record the
Phase CT Ratio, Phase VT Ratio, and Phase Rotation setting values.
4. Apply the current and voltage quantities shown in Column 1 of Table 88.
Values are given for Phase Rotation = ABC and Phase Rotation = ACB.
5. Use the front panel METER or MPS Explorer software to verify the
results.
Table 87 - Power Quantity Accuracy — Wye Voltages
Applied Currents and
Voltages Real Power
(kW)
Reactive Power (kVAR)
Power Factor
(pf)
PHROT = ABC
Ia = 2.5
∠−26
Ib = 2.5
∠−
146
Ic = 2.5
∠
+94
Expected:
P =
0.4523 • CTR1 • PTR
Expected:
Q =
0.2211 • CTR1 • PTR
Expected:
pf =
0.90 lag
Va = 67
∠
0
Vb = 67
∠−
120
Vc = 67
∠
+120
Measured: Measured: Measured:
PHROT = ACB
Ia = 2.5
∠−
26
Ib = 2.5
∠
+94
Ic = 2.5
∠−
146
Expected:
P =
0.4523 • CTR1 • PTR
Expected:
Q =
0.2211 • CTR1 • PTR
Expected:
pf =
0.90 lag
Va = 67
∠
0
Vb = 67
∠+
120
Vc = 67
∠−
120
Measured: Measured: Measured:
825-P
L1
L2
L3
N
Voltage
Test
Source
VA
VB
VC
VN