PUB 50411
D64RP18 SERIES B1 DIGITAL GROUND FAULT RELAY
Revision 2
May, 2005
Page 4
Pulsed (Trip) Auto Reset:
Each time control power is applied, the internal processor of the D64RP18 selects this mode
when it sees a closed circuit on terminals R1 & R2 (there is a jumper or a N.C. pushbutton
connected to R1 and R2). In this mode the N.C. button does not perform a reset function.
The output relay N.O. contact is closed when tripped and the N.C. contact is open when
tripped.
The output relay does not change state when control power is applied to terminals N- & L+.
With control voltage on terminals N- & L+ (Green LED slow flashing), when the measured
values reach or exceed the DIPswitch settings for current and time, the output relay changes
state (trips) and the green LED changes to fast blinking. The output relay will remain tripped
until one of the following conditions is met:
-
Three seconds after the ground fault current drops below the trip current set point the
relay will reset and the green LED resumes slow flashing. This is, in effect, pulsed
Auto Reset.
-
If the control voltage is removed by the trip action of the output relay (i.e. it operates
the shunt trip of the breaker that is providing the control voltage), the relay will reset
with a short delay and the green LED is turned off. This is, in effect, Auto Reset.
If the ground fault has not been cleared when control voltage is restored, the relay will trip and
the green LED will resume fast blink after 500 milliseconds, regardless of the time delay set
on the Trip Delay DIPswitch, and the above cycle will be repeated.
If the ground fault has been cleared when control voltage is restored, the relay will remain
reset.
The Pulsed Trip Auto Reset mode can be used when the application calls for Auto Reset.
The Pulsed Trip Auto Reset mode is designed for applications where the output relay is
operating a shunt trip device. The D64RP18 resets automatically 3 seconds after the ground
fault current is interrupted by the tripping action of the circuit breaker. The output contact to
the shunt trip coil opens. This prevents damage to the internal mechanism of the circuit
breaker in the event that the operator tries to reset the circuit breaker. When the control
voltage to the D64RP18 is interrupted by action of the shunt trip, the D64RP18 resets with a
short delay.
Non-Failsafe:
Each time control power is applied, the internal processor of the D64RP18 selects this mode
when it sees an open circuit on terminals R1 & R2 (there is no contact or a N.O. pushbutton is
connected to R1 and R2).
The output relay N.O. contact is closed when tripped and the N.C. contact is open when
tripped.
The output relay does not change state when control power is applied to terminals N- & L+.
With control voltage on terminals N- & L+ (Green LED slow flashing), when the measured
values reach or exceed the DIPswitch settings for current and time, the output relay changes
state (trips) and the green LED changes to fast blinking.
