DC Ground Fault Protective Relay (64P)
By monitoring the potential difference between the substation
ground pole and the rail, this device detects DC bus line ground
faults in the substation premises for DC electric railways andprotects substation equipment.

Monitors ground faults at
DC bus bar in substation
premises
Monitor potential
difference between
Substation grounding
pole and rail

At or above theregulated voltage,
go trip

Receiving extra-high power

In the event of
DC ground fault,
Trip output

DC busbar64P-Electrical wire＋

During an AC
ground fault,
control theTrip output

AC Output
Suppressi
on Circuit

AC ground
fault

RailHighvoltage
distributionline(AC 6.6 kV)Transformer substation

signal station

DC groundfault
Substation
groundingPurpose and the role of equipment
In the event of a ground fault accident at the substation premises, it is necessary to shut
down the supply of electricity from the substation to the trains.
This device monitors the voltage at the grounding pole (grounding mat) and the negative
return line (rail), and the relay operates and outputs the point of contact if the voltage
exceeds a predetermined value.

No control power supply required
Since no control power supply is required, relay operation is ensured even in theevent of power loss in the plant.

Suppresses unwanted operation of lightning surge
The built-in discharge circuit suppresses unwanted operation due to lightning
damage, etc.

Suppression of Unwanted operation for AC ground fault
The built-in AC/DC ground-fault discrimination circuit and AC suppression filter
circuit ensure that unwanted operations caused by AC ground faults can be avoided.
A 64P (separate product) with AC ground-fault operation suppression is alsoavailable.
We can also customize the system to meet your requirements.

Operating principles
In the event of a ground fault on theDC bus bar Substation, High voltage
between grounding pole and negative
return line (rail) is generated.

RectifierDC bus bar
Bus earth fault
current (Ig)

HSCB

When the electric potential is above thesettling voltage between substation
ground pole and negative return line(rail), the relay operates and outputs acontact point.

Electrical wireRail
DC ground fault
Substation
grounding＋ 64P －Rail leakageresistance(Rr)Groundingresistance(Rg)

Voltage of Ig×（Rg＋Rr）
Ig：Bus earth fault current
Rg：Grounding resistance
Rr：Rail leakage resistance

Earthground

ModelVoltage Rating
Constant Voltage
Tolerance(ambient temperature25°C)

YRV-2

YRV-2-2
1500V

400V/500V/600V

300V/400V/500V

Within ±5% of each regulated voltage

YRV-2L

YRV-3

750V/600V

1500V

200V/250V/300V

400V/500V/600V

Within ±10% of each Within ±5% of each regulated
regulated voltage
voltageReleased voltage

80% or less of each regulated voltage

Control power supplyunnecessary

Ambient
temperature/humidity-10°C to 40°C / 30% to 80%RH (with no condensation)

Operating Time

Within 20ms
(when 110% of each regulated voltage is input)

Within 80 to 160 ms(when 110% of each regulatedvoltage is input)

Action Indication

White (Returned with the attached operating indicator return stick)

Lightning impulse
withstand voltage

Between terminals batch and G (case) ±20kV+, -, A, B, C terminals to other terminals ±20kV+,A terminal to -,B,C terminal ±20kV

Output contact capacity

Contact output 2a Energizing capacity DC 110V 3A (resistive load)
Interrupting capacity DC110V 0.4A (resistive load)

Dimensions
Mass
Coating color

350mm x 400mm x 194.5mm(H x W x D)
Approx. 7.4kg
5Y7/1

YRV-2

620mm x 407mm x 221.5mm(H x W x D)
Approx. 15kg
5Y7/1