GFU20 product page
The GFU20 has been brand labelled for Eaton Corp. as the D64RPBH13
The GFU20 is a ground fault protection unit for use on solidly grounded or resistance grounded systems. This innovative digital electronic unit measures ground fault current using the zero sequence Current Sensors (CS) series with a ratio of 10.000:1 or 500:1. (Go to Sensors.) External Current Sensors with different cable windows, round or square and split core, and various current ratios are available.
The GFU20 reacts to alternating current (AC) only and will reject direct current (DC) signals. It will maintain accuracy over a frequency range of 40 - 200 Hz, making it suitable for variable frequency drive applications.
The GFU20 houses an isolated universal power supply from 110 - 240 V AC or DC and is equipped with an internal voltage-operated tripping device, form ‘C’ (3 connections) change-over NO-C-NC contact set, with an external toggle handle to operate the upstream protection device and to indicate a failure of the system. The Trip Delay Time (25 ms – 1 s, 14 steps), Ground Fault Trip Current level (2,5 A - 60 A with 500:1 ratio and 50 A - 1200 A with 10.000:1, both in 25 steps), Trip Inhibit mode (enabled/ disabled, the values depend on the trip level settings) and the Relay Operating Mode (Non-Failsafe and Failsafe) are set on a front accessible dipswitch array.
The dipswitch array is made ‘tamper proof’, meaning that manipulating the switches will not change the settings, unless a special procedure is followed. If the procedure is not followed correctly the red and green LEDs will flash alternately, indicating an attempt to illegally change the settings. The original settings will stay valid until the entire procedure is followed.
The measured current is compared against two setpoints. The lower one is the Ground Fault (G/F) setpoint, the higher one is the High Current (H/C) setpoint.
The user can select the operation of the unit to be ‘Trip Inhibited’. Together with an upstream tripping device (fuses or breaker) it can protect local contactor contacts in the case of H/C currents. In this case the unit does not trip initially when the measured current exceeds the H/C setpoint, but waits for the upstream device to take care of current interruption and then trips. The latter trip flags the location of the fault to the user and also allows, after inspection for welded contacts, fast re-closure of the upstream tripping device. Should the upstream device fail to perform, then automatic backup protection makes the GFU20 trip, as a last resort, one second after the H/C occurred. This makes it possible to design a Type 2 coordinated installation, according to the IEC 60755 standard and a Class 2, according to the UL 1053 standard. See Table 2 in the manual for values.
The GFU20 is suitable for use on Service Protection Equipment applications.
The GFU20 constantly supervises the connection to the external CS. Open wires are detected and, as it no longer protects the system, will cause a trip. Please note that the GFU20 does not employ any DC injection to implement this, since even small DC current sent through the secondary windings of a CS can bias its core enough to shift the trip point outside specification on sensitive settings. For the CS supervision to work a CS series sensor with a ratio of 10.000:1 or 500:1 must be installed, as specified in the manual.
The cover mounted ‘RESET’ button can be pressed to reset a trip or double pressed to invoke a functional test of the GFU20, the red LED will signal ‘TEST’ with a solid indication in this situation. Provision is also made for an external test button to do a system test including the CS monitoring feature, the red LED will signal ‘CS FAULT’ by 4 consecutive flashes.
A green ‘RUN’ LED shows correct operation by slowly flashing (1 s on/ 1 s off).
A red ‘LAST TRIP’ LED indicates that the GFU20 has sensed a fault and that the output contacts have operated. The blinking sequence of the red LED indicates the type of fault. When the Control Voltage to the GFU20 is removed, pressing the cover mounted reset button will show the green LED solidly on when no fault was detected before power-down. If a fault was present before power-down, the red LED will indicate the fault by the blinking sequence. The fault can only be reset when Control Voltage is present.
A 8 point Pull-apart terminal block simplifies connection of field wiring. Captive screws secure the blocks to the unit, safe from the effects of shock and vibration.
To ensure that the GFU20 will function in severe circumstances, it is encapsulated in polyurethane (PUR) to make sure it is not vulnerable to mechanical shock, vibration nor weather.
GFU20 product page
The GFU20 has been brand labelled for Eaton Corp. as the D64RPBH13.
The GFU20 is a ground fault protection unit for use on solidly grounded or resistance grounded systems. This innovative digital electronic unit measures ground fault current using the zero sequence Current Sensors (CS) series with a ratio of 10.000:1 or 500:1. (Go to Sensors.) External Current Sensors with different cable windows, round or square and split core, and various current ratios are available.
The GFU20 reacts to alternating current (AC) only and will reject direct current (DC) signals. It will maintain accuracy over a frequency range of 40 - 200 Hz, making it suitable for variable frequency drive applications.
The GFU20 houses an isolated universal power supply from 110 - 240 V AC or DC and is equipped with an internal voltage-operated tripping device, form ‘C’ (3 connections) change-over NO-C-NC contact set, with an external toggle handle to operate the upstream protection device and to indicate a failure of the system. The Trip Delay Time (25 ms – 1 s, 14 steps), Ground Fault Trip Current level (2,5 A - 60 A with 500:1 ratio and 50 A - 1200 A with 10.000:1, both in 25 steps), Trip Inhibit mode (enabled/ disabled, the values depend on the trip level settings) and the Relay Operating Mode (Non-Failsafe and Failsafe) are set on a front accessible dipswitch array.
The dipswitch array is made ‘tamper proof’, meaning that manipulating the switches will not change the settings, unless a special procedure is followed. If the procedure is not followed correctly the red and green LEDs will flash alternately, indicating an attempt to illegally change the settings. The original settings will stay valid until the entire procedure is followed.
The measured current is compared against two setpoints. The lower one is the Ground Fault (G/F) setpoint, the higher one is the High Current (H/C) setpoint.
The user can select the operation of the unit to be ‘Trip Inhibited’. Together with an upstream tripping device (fuses or breaker) it can protect local contactor contacts in the case of H/C currents. In this case the unit does not trip initially when the measured current exceeds the H/C setpoint, but waits for the upstream device to take care of current interruption and then trips. The latter trip flags the location of the fault to the user and also allows, after inspection for welded contacts, fast re-closure of the upstream tripping device. Should the upstream device fail to perform, then automatic backup protection makes the GFU20 trip, as a last resort, one second after the H/C occurred. This makes it possible to design a Type 2 coordinated installation, according to the IEC 60755 standard and a Class 2, according to the UL 1053 standard. See Table 2 in the manual for values.
The GFU20 is suitable for use on Service Protection Equipment applications.
The GFU20 constantly supervises the connection to the external CS. Open wires are detected and, as it no longer protects the system, will cause a trip. Please note that the GFU20 does not employ any DC injection to implement this, since even small DC current sent through the secondary windings of a CS can bias its core enough to shift the trip point outside specification on sensitive settings. For the CS supervision to work a CS series sensor with a ratio of 10.000:1 or 500:1 must be installed, as specified in the manual.
The cover mounted ‘RESET’ button can be pressed to reset a trip or double pressed to invoke a functional test of the GFU20, the red LED will signal ‘TEST’ with a solid indication in this situation. Provision is also made for an external test button to do a system test including the CS monitoring feature, the red LED will signal ‘CS FAULT’ by 4 consecutive flashes.
A green ‘RUN’ LED shows correct operation by slowly flashing (1 s on/ 1 s off).
A red ‘LAST TRIP’ LED indicates that the GFU20 has sensed a fault and that the output contacts have operated. The blinking sequence of the red LED indicates the type of fault. When the Control Voltage to the GFU20 is removed, pressing the cover mounted reset button will show the green LED solidly on when no fault was detected before power-down. If a fault was present before power-down, the red LED will indicate the fault by the blinking sequence. The fault can only be reset when Control Voltage is present.
A 8 point Pull-apart terminal block simplifies connection of field wiring. Captive screws secure the blocks to the unit, safe from the effects of shock and vibration.
To ensure that the GFU20 will function in severe circumstances, it is encapsulated in polyurethane (PUR) to make sure it is not vulnerable to mechanical shock, vibration nor weather.