Sr469 Internal Units Per Channel - GE 469 Communications Manual

COMMUNICATIONS GUIDE
Channel
number
0
469 MOTOR MANAGEMENT RELAY – COMMUNICATIONS GUIDE
1185
11A1
Phase CT
The setpoint in modbus register 1180 provides an external factor for calculating phase
current.
Let A represent external scale, where A = value of register 1180.
Let B represent internal scale, where B = 500 for Phase current on SR469.
SF = A/B.
current
Ground CT (type 1A Secondary or type 5A Secondary)
The setpoint in modbus register 1183 provides an external factor for calculating ground
current.
The setpoint in modbus register 1182 has value 1 or value 2, indicating 1A or 5A secondary.
Let A represent external scale, where A = value of register 1183.
Let B represent internal scale, where B = 500 for Ground current on SR469.
SF = A/B.
current
Ground CT (type Multilin CT 50/0.025)
The setpoint in modbus register 1182 has value 3, indicating Ground CT type Multilin CT.
Let A represent external scale, where A = 1 Ampere.
Let B represent internal scale, where B = 500 for Ground current on SR469.
SF = A/B = 0.002 Ampere
current
Phase Differential CT
The setpoint in modbus register 1185 provides an external factor for calculating phase
differential current.
Let A represent external scale, where A = value of register 1185.
Let B represent internal scale, where B = 500 for Phase Differential current on SR469.
SF = A/B.
current
Phase VT
The setpoint in modbus register 11A1 provides an external factor for calculating phase
voltage. The scale factor is:
Let A represent external scale, where A = (120 Volts) * (value of register 11A1).
Let B represent internal scale, where B = 2500 for Phase voltage on SR469.
SF = A/B.
voltage
Input wiring
Phase A current
Differential CT primary
Voltage ratio
Table 3: SR469 Internal Units per Channel
Internal Nominal
units scale Unit
500 1 x CT
MODBUS MEMORY MAP
Current [Ampere]
Ratio [n:1]
External Scale factor
SF or SF
current voltage
CT primary /500
Modbus
register
1180
17