Rockwell Automation 193-EC4 EC4 Current Monitoring Relay User Manual - Manual (Page 29)

30 Rockwell Automation Publication 193-UM011A-EN-P - September 2010
Chapter 2 Installation and Wiring
Figure 13 - External CT Connection Diagrams
External Ground Fault
Sensor Application EC4 Current Monitoring Relays are intended to provide ground fault protection
when used with the Cat. No. 193-CBCT_ external ground fault (core balance)
sensor. The ground fault sensor mounts separately from the EC4 current
monotoring relay and must be placed within three meters of it. The
customer-supplied cable for wiring the ground fault sensor to the EC4 should
meet the specifications outlined in Table 5.
Power Cable Installation Instructions
1. All power cables (including the neutral when used) must pass through the
sensor window. The equipment ground conductor (the conductor used to
carry the non-current-carrying metal parts of equipment, as defined by
Article 100 of the NEC) must not pass through the sensor window.
2. The power cables through the sensor window should be straight, tightly
bundled, centered in the window, and perpendicular to the sensor for a
length equal to or greater than six times the cable diameter (including
insulation) from the sensor.
3. All other conductors with available fault currents in excess of 1 000 A
should be placed a distance equal to or greater than six times the cable
diameter (including insulation) from the sensor.
4. The power cables of the branch circuit to be protected by the EC4 Current
Monitoring Relay must not be grounded on the load side of the ground
fault sensor.
5. If the power cables are enclosed in a conducting jacket, the jacket must be
grounded on the line side of the sensor. The jacket must not pass through
the sensor window, but must be cut at the window and joined with a
conductor that passes outside the sensor window.
IEC NEMA
L1 L2 L3 L1 L2 L3
E3 E3
M
M
K1
T1/2
T1
T2
T3
T2/4 T3/6 T
L1/1 L2/3 L3/5 L
T1/2 T2/4 T3/6
L1/1 L2/3 L3/5
Primary
Current
Transformers
Primary
Current
Transformers