Rockwell Automation 825-P Modular Protection System for Motors User Manual - Manual (Page 106)

106 Rockwell Automation Publication 825-UM004D-EN-P - November 2012
Chapter 7 Metering & Monitoring
Instantaneous Metering
All angles are displayed between –180°…+180°. Delta-connected PT angles are
referenced to VAB or L1 and wye-connected PT angles are referenced to VAN or
L1. If the voltage channels are not supported or if VAB < 13V (for Delta) or
VAN < 13V (for Wye), PT angles are referenced to L1 current.
Thermal Metering
The thermal metering function reports the present values of the RTD input
temperatures and several quantities related to the motor overload protection
function (Table 47).
Table 46 - Measured Values
Relay Option Meter Values
All Models Line Currents L1, L2, and L3
IN (Core-Balance Ground Fault Current) magnitudes (A) and phase angles (°)
IG (Residual Ground Fault Current) magnitude (A) and phase angle (°)
IM (Average Current Magnitude)
Average Motor Load (x I
e
)
Current Imbalance %
System Frequency (Hz)
With Voltage Option VAB, VBC, VCA or VAN, VBN, VCN, VG magnitudes (V) and phase angles (°)
Average Voltage (L-L or L-N)
Voltage Imbalance %
Real Power (kW)
Reactive Power (kVAR)
Apparent Power (kVA)
Power Factor
Real Energy (MWh)
Reactive Energy (MvARh)
Apparent Energy (MvAh)
Table 47 - Thermal Meter Values
Relay Option Thermal Values
All Models Average Motor Load (x I
e
)
Thermal Capacity Used %
Time to Trip (s)
Time to Reset (min)
Starts Available
With External 825-PR12D Module All RTD Temperatures
RTD % Thermal Capacity
NOTE: If the Overload Protection is disabled, the relay always reports % Thermal Capacity = 999
and Calculated Time to Thermal Trip (s) = 9999.