Built-In Current Transformer; External Current Transformer; Interposing Current Transformer - Eaton Cutler-Hammer D64RPB100 Series Instruction Manual

D64RPB100 SERIES B1 DIGITAL GROUND FAULT RELAY
Secure the relay to the DIN rail ensuring the white release latch at the bottom of the relay engages
the rail. If the relay is to be mounted in any other position take appropriate steps to prevent the
relay from becoming disengaged from the DIN rail.
3.2

BUILT-IN CURRENT TRANSFORMER

The D64RPB100 has a built-in current transformer (CT) with 1.81" (46 mm) opening. Conductors
must be insulated for the system voltage when it is higher than 660 Volts.
Refer to Figure 1. Pass the phase conductors through the CT window. If the neutral conductor is
carrying single phase current, it is to be passed through the window. Do not pass ground
conductors through the CT window. In applications that require shielded wires to pass through the
CT window, return the shields through the CT window before connecting them to ground.
Verify that the polarity of the conductors is correct when they pass through the CT. Verify that
ground paths do not exist that would bypass the CT.
The D64RPB100 Trip Level range is 30 mA to 9.0 Amps when using the built-in CT. The
maximum continuous primary phase current is to be 200 Amps.
3.3

EXTERNAL CURRENT TRANSFORMER

Refer to the Glossary of Terms to determine if an external Current Transformer is required for the
application.
The D64RPB100 will work with Eaton's Cutler-Hammer C311CT current transformers having a
turns ratio of 500:1. These are epoxy molded to give exceptional mechanical properties and have
high-grade silicon iron cores for excellent coupling characteristics.
Refer to section 5 to select the catalog number of the C311CT current transformer with the
opening required for the application.
Phase conductors must be insulated for the system voltage when it is higher than 660 Volts.
Refer to Figure 2. Pass the phase conductors through the CT window. If the neutral conductor is
being connected downstream, it is to be passed through the window. Do not pass ground
conductors through the CT window. In applications that require shielded wires to pass through the
CT window, return the shields through the CT window before connecting them to ground.
Verify that the polarity of the conductors is correct when they pass through the CT. Verify that
ground paths do not exist that would bypass the CT.
Position power cables in the center of the current transformer opening. Keep cables and buswork
clear of the split on split core current transformers.
The two secondary terminals of the external CT are to be connected to terminals T1 and T2 of the
D64RPB100.
3.4

INTERPOSING CURRENT TRANSFORMER

Refer to the Glossary of Terms to determine if an interposing Current Transformer is required for
the application.
The D64RPB100 will work with any commercially available 500:5 or 5000:5 ratio CT.
Phase conductors must be insulated for the system voltage when it is higher than 660 Volts.
Refer to Figure 3. Pass the phase conductors through the CT window. If the neutral conductor is
being connected downstream, it is to be passed through the window. Do not pass ground
conductors through the CT window. In applications that require shielded wires to pass through the
CT window, return the shields through the CT window before connecting them to ground.
Revision 3
April, 2008 Page 9
PUB 50412