External Current Sensors


The external Residual Current Sensors are available in 500:1, 1000:1, 2000:1 and 10.000:1 ratio and are limited for the output voltage to max. 27 Vrms. High voltages in the case of loose or broken wires are thus avoided. The Current Sensor measures the residual ground fault current according to the Core Balance principle, in that all the current carrying conductors, including the Neutral wire, are fed through the sensor.
Normal Core Balance Transformers are made from 2 possible metal groups, mu-metal or Silicon Iron and have an as low as possible winding count to make sure that a high amplification factor is maintained. Both metals have their drawbacks:
Both metal groups are not linear and have their largest error in the low current region.
Mu-metal is very sensitive to low temperatures. Below 0°C most mu-metals stop operating, just when ice deposition is a ground fault hazard.
The power conversion of Silicon-Iron is poor, so bigger cross-section cores are used. The lower the detection level, the bigger the cross-section has to be.
Mu-metal is sensitive to lock-up due to DC currents. Over a long time it may restore, but one never knows when and how good the core will perform when needed. A high AC current can restore the correct trip point, at the cost of a system trip.
Modern electronics, with some precautions, can overcome the standard problems with Silicon-Iron materials. The drawbacks of mu-metals are material related and cannot be handled by electronics and are most dangerous to use due to lock-up and low temperature behaviour.
Our state-of-the-art Ground Fault protection devices consisting of Silicon-Iron core material with a small cross-section area to save material and highly integrated electronics make it possible to have an accurate trip current range from 30 mA to 60 A and a Short Circuit detection of over 160 A using one and the same Current Sensor.
These sensors are compatible with all ground fault relays produced by GFS: DGF7-types, DGF10, DGF100, GFU20 and GFU21.
This includes the products brand labelled for Eaton Corp. : D64RPBH13, D64RP14, D64RPBH15, D64RP18, D64RPB30 and D64RPB100.
Brand labelled for Eaton Corp. South Africa : JCB61, JCB61-1, JCB61-1 JM and JCB61-1 JM1
GFS manufactures Current Sensors brand labelled for Eaton Corp. known under the following names:
CS5-028
CS5-050
CS5-065
CS5-090
CS5-150
CS5-240
C311CT28
C311CT1
C311CT9
C311CT2
C311CT5
C311CT6
CS5-1517
CS5-1035
CS5-3030
C311CT3
C311CT4
C311CT7
CS100-095
CS100-144
CS100-240
CS100-2028
C311CT14
C311CT12
C311CT13
C311CT15
For the complete list of brand labelled units and sensors go here.
Round window External Current Sensors


Dimensions in mm | Current ratio | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
A | B | C | D | E | F | G | H | I | 500 | 1000 | 2000 | 10.000 |
65 | 112 | 63 | 30 | 120 | 15 | 17 | 29 | --- | --- | --- | --- | |
90 | 125 | 75 | 30 | 136 | 15 | 17 | 29 | --- | --- | --- | --- | |
95 | 150 | 75 | 45 | 150 | 25 | 16 | 23 | --- | --- | |||
144 | 207 | 105 | 48 | 204 | 28 | 20 | 37 | 55 | --- | |||
150 | 207 | 105 | 40 | 204 | 20 | 20 | 37 | 55 | --- | --- | --- | |
240 | 305 | 150 | 40 | 305 | 20 | 20 | 37 | 55 |
Click on the name of the Current Sensor to go to the product page
Ratio | Window size | |||||
---|---|---|---|---|---|---|
65 | 90 | 95 | 144 | 150 | 240 | |
500:1 Price Stock |
€ |
€ |
--- |
--- |
€ |
€ |
1000:1 Price Stock |
--- |
--- |
€ |
€ |
--- |
€ |
2000:1 Price Stock |
--- |
--- |
€ |
€ |
--- |
€ |
10.000:1 Price Stock |
--- |
--- |
€ |
€ |
--- |
€ |
Square window External Current Sensors


Dimensions in mm | Current ratio | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
A | B | C | D | E | F | G | H | I | J | K | L | 500 | 1000 | 2000 |
150 | 170 | 293 | 225 | 180 | 265 | 20 | 20 | 40 | 20 | 38 | 55 | --- | --- | |
103 | 250 | 373 | 196 | 140 | 345 | 20 | 20 | 40 | 20 | 38 | 55 | |||
102 | 350 | 477 | 198 | 142 | 449 | 20 | 20 | 40 | 20 | 38 | 55 |
Click on the name of the Current Sensor to go to the product page
These sensors are available in both split and un-split versions.
In un-split versions dimensions E, F and G are not applicable.
Ratio | Window size Square |
||
---|---|---|---|
1517 | 1025 | 1035 | |
500:1 Price Stock |
€ |
€ |
€ |
1000:1 Price Stock |
--- |
€ |
€ |
2000:1 Price Stock |
--- |
€ |
€ |
Top-Hat External Current Sensors

Dimensions in mm | Current ratio | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
A | B | C | D | E | F | G | H | I | J | K | L | M | 500 | 1000 | 2000 | 10.000 |
300 | 300 | 470 | 440 | 360 | 406 | 30 | 60 | 64 | 260 | 440 | 12 | 17 | --- | --- | --- | |
200 | 286 | 387 | 282 | --- | --- | --- | 40 | --- | 241 | 363,5 | 12 | 17 |
Click on the name of the Current Sensor to go to the product page
The CS5-3030 is available in both split and un-split versions.
In the un-split version dimensions E, F and G are not applicable.
For the CSxx-2028 split-core versions are not available
Ratio | Window size | |
---|---|---|
2028 | 3030 | |
500:1 Price Stock |
€ |
€ |
1000:1 Price Stock |
€ |
--- |
2000:1 Price Stock |
€ |
--- |
10.000:1 Price Stock |
€ |
--- |
External Current Sensors


The external Residual Current Sensors are available in 500:1, 1000:1, 2000:1 and 10.000:1 ratio and are limited for the output voltage to max. 27 Vrms. High voltages in the case of loose or broken wires are thus avoided. The Current Sensor measures the residual ground fault current according to the Core Balance principle, in that all the current carrying conductors, including the Neutral wire, are fed through the sensor.
Normal Core Balance Transformers are made from 2 possible metal groups, mu-metal or Silicon Iron and have an as low as possible winding count to make sure that a high amplification factor is maintained. Both metals have their drawbacks:
Both metal groups are not linear and have their largest error in the low current region.
Mu-metal is very sensitive to low temperatures. Below 0°C most mu-metals stop operating, just when ice deposition is a ground fault hazard.
The power conversion of Silicon-Iron is poor, so bigger cross-section cores are used. The lower the detection level, the bigger the cross-section has to be.
Mu-metal is sensitive to lock-up due to DC currents. Over a long time it may restore, but one never knows when and how good the core will perform when needed. A high AC current can restore the correct trip point, at the cost of a system trip.
Modern electronics, with some precautions, can overcome the standard problems with Silicon-Iron materials. The drawbacks of mu-metals are material related and cannot be handled by electronics and are most dangerous to use due to lock-up and low temperature behaviour.
Our state-of-the-art Ground Fault protection devices consisting of Silicon-Iron core material with a small cross-section area to save material and highly integrated electronics make it possible to have an accurate trip current range from 30 mA to 60 A and a Short Circuit detection of over 160 A using one and the same Current Sensor.
These sensors are compatible with all ground fault relays produced by GFS: DGF7-types, DGF10, DGF100, GFU20 and GFU21.
This includes the products brand labelled for Eaton Corp. : D64RPBH13, D64RP14, D64RPBH15, D64RP18, D64RPB30 and D64RPB100.
Brand labelled for Eaton Corp. South Africa : JCB61, JCB61-1, JCB61-1 JM and JCB61-1 JM1
GFS manufactures Current Sensors brand labelled for Eaton Corp. known under the following names:
CS5-028
CS5-050
CS5-065
CS5-090
CS5-150
CS5-240
C311CT28
C311CT1
C311CT9
C311CT2
C311CT5
C311CT6
CS5-1517
CS5-1035
CS5-3030
C311CT3
C311CT4
C311CT7
CS100-095
CS100-144
CS100-240
CS100-2028
C311CT14
C311CT12
C311CT13
C311CT15
For the complete list of brand labelled units and sensors go here.
Round window External Current Sensors


Dimensions in mm | Current ratio | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
A | B | C | D | E | F | G | H | I | 500 | 1000 | 2000 | 10.000 |
65 | 112 | 63 | 30 | 120 | 15 | 17 | 29 | --- | --- | --- | --- | |
90 | 125 | 75 | 30 | 136 | 15 | 17 | 29 | --- | --- | --- | --- | |
95 | 150 | 75 | 45 | 150 | 25 | 16 | 23 | --- | --- | |||
144 | 207 | 105 | 48 | 204 | 28 | 20 | 37 | 55 | --- | |||
150 | 207 | 105 | 40 | 204 | 20 | 20 | 37 | 55 | --- | --- | --- | |
240 | 305 | 150 | 40 | 305 | 20 | 20 | 37 | 55 |
Click on the name of the Current Sensor to go to the datasheet
Ratio | Window size | |||||
---|---|---|---|---|---|---|
65 | 90 | 95 | 144 | 150 | 240 | |
500:1 Price Stock |
€ |
€ |
--- |
--- |
€ |
€ |
1000:1 Price Stock |
--- |
--- |
€ |
€ |
--- |
€ |
2000:1 Price Stock |
--- |
--- |
€ |
€ |
--- |
€ |
10.000:1 Price Stock |
--- |
--- |
€ |
€ |
--- |
€ |

price: €
In stock:
Square window External Current Sensors


Dimensions in mm | Current ratio | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
A | B | C | D | E | F | G | H | I | J | K | L | 500 | 1000 | 2000 |
150 | 170 | 293 | 225 | 180 | 265 | 20 | 20 | 40 | 20 | 38 | 55 | --- | --- | |
103 | 250 | 373 | 196 | 140 | 345 | 20 | 20 | 40 | 20 | 38 | 55 | |||
102 | 350 | 477 | 198 | 142 | 449 | 20 | 20 | 40 | 20 | 38 | 55 |
Click on the name of the Current Sensor to go to the datasheet
These sensors are available in both split and un-split versions.
In un-split versions dimensions E, F and G are not applicable.
Ratio | Window size Square |
||
---|---|---|---|
1517 | 1025 | 1035 | |
500:1 Price Stock |
€ |
€ |
€ |
1000:1 Price Stock |
--- |
€ |
€ |
2000:1 Price Stock |
--- |
€ |
€ |
Top-Hat External Current Sensors

Dimensions in mm | Current ratio | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
A | B | C | D | E | F | G | H | I | J | K | L | M | 500 | 1000 | 2000 | 10.000 |
300 | 300 | 470 | 440 | 360 | 406 | 30 | 60 | 64 | 260 | 440 | 12 | 17 | --- | --- | --- | |
200 | 286 | 387 | 282 | --- | --- | --- | 40 | --- | 241 | 363,5 | 12 | 17 |
Click on the name of the Current Sensor to go to the datasheet
The CS5-3030 is available in both split and un-split versions.
In the un-split version dimensions E, F and G are not applicable.
For the CSxx-2028 split-core versions are not available
Ratio | Window size | |
---|---|---|
2028 | 3030 | |
500:1 Price Stock |
€ |
€ |
1000:1 Price Stock |
€ |
--- |
2000:1 Price Stock |
€ |
--- |
10.000:1 Price Stock |
€ |
--- |