Littelfuse Startco Protection Relays
Technical Note - Resistance Grounding
RG-06 : SE-VS1002K VOLTAGE SCALER FOR THE SE-325
In some SE-325 NGR Monitor applications the required RES TRIP LEVEL (VAC) setting may be above the 20K
RES set-point range. To increase the RES TRIP LEVEL (VAC) range on an SE-325 when using a 20 k Ω sensing
resistor, install an SE-VS1002K Voltage Scaling Device. For new applications, Littelfuse Startco recommends the
use of an SE-330 NGR Monitor.
101.6
(4.00)
F1
NOTES:
1.
WITH SE-VS1002K INSTALLED ACROSS
R & G OF SE-325 NGR MONITOR AND USIN
20
SENSING RESISTOR
(SE-325 SETTING: RES IN 20K POSITION)
THE RES TRIP LEVEL POTENTIOMETER
RANGE IS TIMES FIVE (100 VAC TO 2 KVAC
CT1 CT2
A
B
L1
L2
GROUND
FAULT
150.0
(5.90)
1.0
RESET
RESISTOR
FAULT
200
1000
0.1
2.0
GF TRIP
TIME (s)
GF MODE RES
4.0 A SH
100K
2.0 A
0.5 A UV 20K
20
100
400
2000
RES TRIP
LEVEL (VAC)
SE-325
NGR MONITOR
SW GI
RI
R
G
40.0
(1.58)
SE-VS1002K
33.0
(1.30)
100 V TO 2 KV SCALE
WITH 20 K SENSOR.
CONNECT ACROSS
R AND G
STARTCO
ENGINEERING LTD.
MADE IN SASKATOON, CANADA
R
G
TO 20 k
Ω
SENSING RESISTOR
SE-VS1002K VOLTAGE SCALER INSTALLATION
© 2011 Littelfuse Startco
www.startco.ca
1
Pub. TN-RG06, June 6, 2005