Related Manuals for Nortech F20
Summary of Contents for Nortech F20
- Page 1 Twin Earth Fault Indicator USER MANUAL Version 1.2 © Nortech Management Ltd, United Kingdom November 2016 www.nortechonline.co.uk Doc ref: D_001116...
- Page 2 Twin Earth Fault Indicator Publication Notice Copyright © Nortech Management Limited (NML). All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, including photocopying, electronic, mechanical, recording or otherwise, without the prior written permission of the copyright holder.
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Page 3: Table Of Contents
Technical Assistance ..............13 Simple Test................13 Primary Injection ............... 13 Replace battery ................. 13 Recycling .................. 13 Specification ................... 14 General ..................14 EMC ..................14 Environmental ................15 Notices ..................16 © Nortech Management Ltd, United Kingdom Page 3 of 16... -
Page 4: Description
MV network is responsible for the interruption of consumer supplies. The F20 has two independent Earth Fault (EF) elements. This allows the F20 to be used to monitor both the incoming and outgoing cables at a Ring Main Unit site on the distribution network. -
Page 5: Operation
The default value is 3 hours flashing when a fault is detected. Different indication periods may be selected to suit local requirements either at time of order or in the field using a laptop and the F20 Field Support Kit. Reset... -
Page 6: Test
Twin Earth Fault Indicator The F20 requires the fault to be present for a minimum of 50ms, the operating curve can be assumed to be close to definite time. Test A simple manual test of the F20 is achieved by pressing each of the TEST buttons. -
Page 7: Operation Worked Examples
The examples below illustrate how applying electrical reset can affect detection and indication of faults. The examples assume the F20 is configured with a 3 hour indication period and consider only one Earth Fault element. The three faults occur at 2 hour intervals. After Fault 1 supplies are lost for 1 hour. -
Page 8: Indication With Dc Reset Signal
Fault 2 Fault 3 fault current time DC reset signal In all cases RTU sends DC reset signal as soon as F20 indication is detected. F20 time resets within 1 second of DC reset signal LED indication and relay contacts... -
Page 9: Installation
The LED and buttons are located on the front of the F20. The F20 should be mounted for good visibility and as close as practical to the CT earthing For safety reasons, it is normal practice for the CT to be mounted in a position over the cable sheath or screening tape, and in accordance with local safety regulations. -
Page 10: Ct Connections
Twin Earth Fault Indicator CT connections The CT arrangement the F20 will be used with is a factory set option. Wire the summated output from the CT secondary’s to the CT terminals of the F20. Wire the output from the CT secondary The current transformers should be to the CT terminals of the F20. -
Page 11: Wiring Connections
Twin Earth Fault Indicator Wiring connections F20 wiring connections are provided as screw terminals inside the lid of the enclosure. If mounted within a cable termination enclosure, one core of the CT should be connected to earth for safety. Power Supply If it is not already connected the battery should be plugged in. -
Page 12: Enclosure Mounting
Twin Earth Fault Indicator Enclosure Mounting The enclosure has four 4mm fixing holes suitable for use mounting the F20 on a wall or switchgear bracket. 4 off Mounting holes 90.0mm Rear view of F20 enclosure 122.0mm 110.0mm 120.0mm F20 enclosure fixing holes 4.5.1... -
Page 13: Maintenance
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. © Nortech Management Ltd, United Kingdom Page 13 of 16... -
Page 14: Specification
One set of contacts for each Earth Fault element. DC Remote Reset 12V-24V dc for 1000ms AC Remote Reset 90V-240V ac for 10 seconds The F20 indicator has been designed for compliance in accordance with the high level standard 61326-1:2006 industrial class. Immunity IEC61000-4-2 4kV contact, 8kV air... -
Page 15: Environmental
Humidity 0-95% non-condensing Storage: In addition to the above environmental considerations, the F20 should be stored in an environment that is dry, corrosive-free, and not in direct sunlight. Correct storage: Prevents premature component failures caused by environmental factors such as moisture or corrosive gases. -
Page 16: Notices
Isolate from mains before removing cover (only where 100-240V AC connected by 50-60Hz user) 100mA rated current Disposal Battery and F20 unit should be disposed of in accordance with local regulations. © Nortech Management Ltd, United Kingdom Page 16 of 16...