PUB 50411
D64RP18 SERIES B1 DIGITAL GROUND FAULT RELAY
Revision 2
May, 2005
Page 8
Refer to Figure 3 for mounting dimensions of the D64RP18 relay. It is designed to be mounted with
either mounting screws or 35 mm DIN rail.
Two #8-32 x 3/4" (M4 x 20) mounting screws are required for screw mounting.
For DIN rail mounting the rail should be bolted to a flat surface. Install the DIN rail horizontally. Allow at
least ¾” (20 mm) of rail to extend beyond each end of the 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 D64RP18 has a built-in current transformer (CT) with 1.1” (28 mm) opening.
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 D64RP18 Trip Level range is 30 mA to 6.0 Amps when using the built-in CT. The maximum
continuous primary phase current is to be 100 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 D64RP18 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 4 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
D64RP18.
3.4
CONNECTIONS
All connections to the D64RP18 are by means of screw clamp terminals rated 10 Amps, 300 Volts.
Terminals will accept #26-12 AWG solid or stranded conductors.
