PUB 50411
D64RP18 SERIES B1 DIGITAL GROUND FAULT RELAY
Revision 2
May, 2005
Page 9
The terminals are pull apart.
If an external CT is being used, connect the two secondary terminals of the CT to terminals T1 and T2
of the relay using 14 AWG (minimum). Twist the leads to optimise electromagnetic immunity.
Note
: The CT’s input terminals T1 and T2 are NOT isolated from the control voltage. If an external
CT is used it is grounded internally via the power supply input and
must not
be grounded
again externally (ground loops).
For Non-Failsafe operation leave terminals R1 and R2 open or connect a N.O. momentary contact
TEST/RESET button to these terminals.
For Pulsed Trip Auto Reset operation install a jumper between terminals R1 and R2 or connect a N.C.
momentary contact TEST button to these terminals.
Note
: Terminals R1 and R2 are NOT isolated from the control voltage; terminal R2 is internally
connected to terminal N-.
Connect ac or dc control power to terminals N- and L+. Observe polarity.
In order to meet the Electromagnetic Compatibility (EMC) requirements a chassis bond is required
between terminal N- and the nearest ground point. This distance should be kept to an absolute
minimum. If the D64RP18 is mounted on 35 mm DIN rail a DIN rail mounted ground terminal block can
be installed beside the relay to act as the chassis ground point.
Refer to Figure 1, Figure 2, and Table 2. Decide on the connection of field devices to control voltage
and output relay contact terminals by comparing the desired control of the field devices under various
operating conditions.
Figure 1 shows the D64RP18 using its built-in current transformer and a typical connection of an ac
motor starter coil (1M). A remote Reset button with N.O. contacts is connected to terminals R1 and R2
providing Non-Failsafe operating mode. Comparing the operating mode and the output relay contact
states in Table 2, it can be seen that the N.C. contact, terminals 11 & 12, would be used for the starter
coil circuit and the N.O. contact, terminals13 and 14, would control the external red TRIP light. A
manual reset is required after a ground fault trip
Figure 2 shows the D64RP18 using an external current transformer (C311CT 500:1 ratio) and a typical
connection of a circuit breaker with a shunt trip coil (ST). A remote pushbutton with N.C. contacts is
connected to terminals R1 and R2, providing Pulsed Trip Auto Reset operating mode. Comparing the
operating mode and the relay contact states in Table 2, it can be seen that the N.O. contact, terminals
13 and 14, would be used for the shunt trip coil. The D64RP18 will reset automatically as soon as the
ground fault current is interrupted by the tripping action of the circuit breaker.
3.4.1
CONNECTING MORE THAN ONE D64RP18 TO REMOTE TEST/RESET
Up to 5 D64RP18 relays in the same enclosure may share a common remote Test/Reset button.
Connect one terminal of the button to terminal R2 of
one
of the units, and connect the other terminal of
the button to terminals R1 of
all
the units in parallel.
Those relays that are to operate in the Pulsed Trip Auto Reset mode should be have the R1 terminal of
all
units connected to a N.C. Button. Those relays that are to operate in the Non-Failsafe mode should
have the R1 terminal of
all
units connected to a N.O. Button.
4.
CATALOG NUMBERS
D64RP18
Ground Fault Relay with built-in 1.1” (28mm) CT, 24 – 240 Volts ac or dc control
voltage, for use on 660 Volts maximum, 50/60 Hz power system.
