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Topic Title: Cable Spiking
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Created On: 10 May 2010 11:19 AM
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 10 May 2010 11:19 AM
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Badshah

Posts: 38
Joined: 22 July 2009

If we want to spike a cable ..what is the safety clearance to be given while pulling out the pin?

If the wrong cable is spiked and still not sure about the dead cable..what other methods can be employed to identify the dead cable?

If the cable is laid in congested area , whether cable spiking can be done, considering the chance of Flashover?

is there any standards or procedures available to refer for this activity?, please mention.

Regards
Badshah
 10 May 2010 01:51 PM
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simongallagher

Posts: 148
Joined: 28 July 2005

Sounds like you need to put in some safe working practices!

First of all you need to identify the cable you wish to work on, this can be done a number of ways (dig back to switch gear, use an approved device to inject a signal that you can pick up in the cable, and not the other).

Always uncover all cables in the vicinity, and check them for the signal.

Only then can you prove in dead by spiking.

Edited: 10 May 2010 at 02:09 PM by simongallagher
 11 May 2010 08:27 PM
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Ben A Prince

Posts: 33
Joined: 22 March 2007

As part of safe system of work on a known cable, spiking provides physical proof that a cable is dead at the point of work. Typically a tone generator is applied to the cable under a test document, the tone is obtained at the point to be spiked and the cable spiked with the tone on (the tone should be lost past the point of spiking as the chisel blade of the spiker acts as a short if successful). Typically the tone generator is then removed, earths reapplied and the test document canceled. A work document can then be issued and the cable cut adjacent to the spiker prior to its removal and the commencement of work proper.

I am much more familiar with the Accles and Shelvoke 'Acvoke' cartridge operated tool than the hydraulic type linked to above. With the cartridge operated tool (and the correct sized cartridge for the cable) the chisel penetrates at great speed, through the cables earthed screen and into the cores. This forceful high speed action (mimicking the action of a fault rated switch) minimises the risk of a flashover if an energised cable were inadvertently spiked. Some sites have rules prohibiting the use of cartridge operated tools but for me the 'risk' of using a slow footpump operated spike into a potentially energised cable seems to present a greater risk. As an alternative I seem to remember another manufacturer produces a remote control battery operated device although I cant remember who.

The real challenge comes with supposedly abandoned cables which don't appear on plans or records and need to be spiked to allow them to be removed. In these cases it isn't possible to isolate, earth and apply a tone (because you don't know where the ends are) and you are left with using a scanner to listen for mains hum (often misleading) and spiking whilst asking anyone with an interest in cables in the vicinity (utility, site owner, etc) to monitor for alarms and loss of power. Not an ideal situation.

Please note my musings do not in any way represent a comprehensive safe system of work and I would suggest that spiking is best implemented by experienced engineers - be careful out there.
 11 May 2010 10:25 PM
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alancapon

Posts: 5759
Joined: 27 December 2005

We went back to the hydraulic spiking tool. Changes to legislation here would have led to us needing a firearms licence and a strong-box for using / carrying the cartridges. It was easier to get the hydraulic tools and surrender the unused cartridges to the police.

Regards,

Alan.
 16 May 2010 03:26 PM
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ArthurHall

Posts: 735
Joined: 25 July 2008

I agree with Alan. A number of years ago we had a batch of faulty cartridges. You pulled the rope and there was just a fizz and a puff of smoke. What do you do then? with a spike possiably only partially into a potentialy live cable.
 17 May 2010 05:58 AM
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Badshah

Posts: 38
Joined: 22 July 2009

Thanks to all

A recent incidnet in our organization caused flashover while cable spiking. For this occasion, what kind of uniform need to be wore by the employee.
Normal FR rated clothing is enough or special flash protection clothing is required? If flash protection clothing is required, what will be the HRC rating for 11KV distribution system.

Once again i thank all for the valuable information & advice.

Regards,
Badshah
 17 May 2010 02:11 PM
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dlane

Posts: 690
Joined: 28 September 2007

As the others have said you should be using cable spiking as a last resort after you have exhausted other means of identifying and proving the cable dead.

I do not know where you are from, but PPE should be a last resort and that is seen as pretty much manadatory here in the UK. You would be expected to take other precaustions such as distancing your self or providing shielding before issuing PPE.

Arc flash isn't just about heat, there is also a pressure wave, shrapnel, noise and light generated that can all cause injuries that FR PPE will not protect against.

In the UK, the fault level on an 11kV system is generalised at around 250MVA, the arc rating of that can be anything from 6 cal\cm^2 upwards depending upon the fault clearance time of the protection system and breaker(s) feeding the circuit.

Standard FR clothing is rated for around 4-5 cal/cm^2 after that it can be torn open by the pressure wave from an arc blast, so you move to appropriately rated arc resistant PPE that is made from the same fabric but utilises different construction methods.

The only way you will know what energy levels you could be exposed to would be to carry out the calculations based on the IEEE 1584 standard or use the tables in the NFPA70E standard if your system falls into the parameters for their use.

Kind regards

Donald Lane
 17 May 2010 05:08 PM
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simongallagher

Posts: 148
Joined: 28 July 2005

If you are so close thet you are considering protecting your people with Arc rated clothing, you are far to close to the spiking gun. PPE is the last line, use other control measures first (robust cable ID policy, well maintained and serviced spiking gun, good distance from point of spike. etc.).
 06 October 2011 05:10 PM
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jdrodri2671

Posts: 1
Joined: 06 October 2011

Badshah, you can get quite a bit of information from some US sites like OSHA.gov. Obviously if you don't live in the US the rules themselves don't apply but at least you will have some sense of what you may need. Cable identification is key but many times in an older system the records and cable tagging are not accurate. That is when the pulse cable identifier are helpful. Keeping your workers as far away as practical is the best practice so remote operation of spikers or at least something that you can use with a long fiberglass hot stick should be considered. We use 8 calorie or higher clothing for field work depending on the available fault current.( Our system is 13kv
 13 June 2012 06:24 PM
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sshamzah1

Posts: 2
Joined: 28 December 2002

the best alternative is remote hydraulic spiking. i have just launched one request for quotation for this type of equipment and expect replies from bidders in two weeks. i have heard about the accles and shelvoke equipment. does anybody have an idea on how efficient and safe is this equipment
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