![background image](http://html1.mh-extra.com/html/eaton/cutler-hammer-d64rpb100-series/cutler-hammer-d64rpb100-series_instruction-manual_526718003.webp)
PUB 50412
D64RPB100 SERIES B1 DIGITAL GROUND FAULT RELAY
Revision 3
April, 2008
Page 3
1.
GENERAL DESCRIPTION
The D64RPB100 is a microprocessor based ground fault relay for use on solidly grounded or resistance
grounded systems. This innovative digital electronic relay measures ground fault current using a built-in
1.81” zero sequence current transformer (CT).
The D64RPB100 reacts to alternating current only and will reject direct current signals. It will maintain
accuracy over a frequency range of 40 to 450 Hz., making it suitable for variable frequency drive
applications.
660 Volts is the maximum system operating voltage for the D64RPB100 when passing the system power
conductors through the built-in CT. However, by using any Eaton’s Cutler-Hammer C311CT 500:1 ratio CT
and connecting the secondary to CT input terminals T1 & T2 or, by using any suitably rated, commercially
available, interposing CT with 5 Amp secondary, and passing the secondary lead through the built-in CT,
the relay can be used on any system voltage.
The ground fault current trip level is set on a front accessible binary DIPswitch array. Using the built-in
1.81” CT or, by using any Cutler-Hammer C311CT 500:1 ratio CT and connecting the secondary to CT
input terminals T1 & T2, trip currents from 30 milliamps - 9 Amps can be selected in 14 discrete steps. By
using an interposing CT with 500:5 ratio, the trip current settings become 3 – 900 Amps. Or, by using an
interposing CT with 5000:5 ratio, the trip current settings become 30 – 9000 Amps. The trip level can be
set just above the charging current
1
. Any deterioration in the circuit will trip the relay. This also permits
scheduled field testing of the relay (by lowering the trip level).
1
The capacitance-to-ground charging current on a system will vary depending on: the overall
length of the cables; the types of loads; the quality of insulation on the phase conductors; the
surrounding equipment grounding, cable trays, junction boxes, etc.; and, the type of transformer.
A "Rule-of-Thumb" for systems 600 Volts and lower: The charging current is 0.5 Amps per 1000
kVA of transformer capacity.
The response time on ground fault trip is set on a front accessible binary DIPswitch array. The range is 20
ms - 5.00 second in 8 discrete steps.
The output relay has Form “Z” (4 terminal) N.O. and N.C. contacts which may be used to operate the
upstream protective device and to indicate a failure of the system. The relay can be set to operate in any
one of the following modes: Failsafe; Non-failsafe; or Pulsed Output Auto Reset, by means of front
accessible DIPswitches.
By double clicking the cover mounted RESET button a functional test of the D64RPB100 is invoked. A
single press of the RESET button resets the relay after a trip. A green RUN LED flashes to indicate when
control power is applied to terminals 1 & 2. A red TRIP LED indicates that the D64RPB100 has sensed a
ground fault current higher than the trip level for a period longer than the trip time and that the output
contacts have operated.
7 point and 3 point pull-apart terminal blocks simplifies connection of field wiring. A captive screw secures
the 7 point block to the relay, safe from the effects of shock and vibration. Terminals are provided for a
remote TEST/REST pushbutton.
A communications port provides access for remote displays (D64D1 or D64D2), computer interface, or
custom interface control modules.
The D64RPB100 operates on any control voltage from 24 – 240 Volts ac or dc.