F20
Twin Earth Fault Indicator
© Nortech Management Ltd, United Kingdom
Page 13 of 16
5
Maintenance
5.1
Technical Assistance
In case of technical assistance please contact either the supplier of the F20 or
Nortech, please see
In case of mal function contact Nortech.
5.2
Simple Test
Press and hold down the left TEST/RESET button (under the EFI1 label). The
left LED (EFI1) will light for 3 seconds then start to flash. The EF1 relay
contacts will not operate. Release the button and the LED will stop flashing.
Repeat for right hand button to test the EFI2 LED.
5.3
Primary Injection
If possible primary injection of current into the CT(s) is recommended.
For core balanced CTs mounted external to the switchgear Nortech
manufacture a Test Set which can be used for this purpose.
For phase CTs mounted internal to the switchgear it is often considered
unnecessary to retest the CT wiring to the F20.
5.4
Replace battery
The battery will provide up to 20 years life and 1000 hours of flashing
indication (or 500 hours if both LEDs are operating). Battery life is subject to
environmental conditions.
When replacement is necessary contact Nortech for a replacement part. The
old battery pack is simply unplugged and the new pack plugged in.
Re-test indicator for correct operation.
5.5
Recycling
When replacing the internal battery dispose of the old lithium battery
responsibly in accordance with local rules.
F20 units may be returned to Nortech for recycling at the end of their life.
