Does supervision by competent persons apply to HV?

[Sparky Ninja]

Chaps,

I was browsing through some sites today and came across this.
I was fascinated at the fact that the guy carried out his duties without the necessary PPE and on someone else's word that it was isolated? I would have assumed it would be down to every individual carrying out the work to HV systems to be competent to work on it, and use the necessary tools and equipment?? Or is this not the case?

 

[sbrown2]

I agree. I would have thought all of the different procedures for ensuring a safe system of work should have formed part of a permit to work procedure. This should have encompassed PPE, types of tools, lock off procedure, authorised person, dead line check etc.

The fines the company received will really deter companies from this malpractice in the future!!!

 

[Deleted member 26818]

It is common practice to rely on someone else's word on isolation for HV systems.
At least, it used to be.

 

[KFH]

This is why so many injury lawyers are in business for the "I was given the wrong sort of ladder" claim. HSE guidance makes it clear that it is the concern of everyone that they have the right equipment, tools and training and that people have to take personal responsibility for their own and everyone else’s safety. Someone successfully claimed against their employers when they put a ladder against the side of the branch they were cutting off a tree with predictable results!

But it is difficult to know what sort of environment is in operating in any business e.g. do you lose your job if you complain? Having said that I want to check myself that something is isolated even on LV and on HV I would want the works in terms of PPE having seen some of the clips on YouTube of what can happen if it goes wrong. In my youth I have tested too many RCDs without using the test button, each time I have become more cautious.

Perhaps we should have an anonymous "I learnt something from that" thread where we can share our embarrassing moments for the benefit of others?

 

[Knobhead]

An authorised person can issue a PTW to a competent or nominated person. The competent should add his safety lock(s) to the Point(s) of Isolation (POI) or Circuit Main Earth(s) (CME) and retain the key. If the work involves contact with HV conductors then a CME should be used, for a mechanical task then POI.

It was drummed in to me “never take anyone’s word”

 

[sbrown2]

It was drummed in to me “never take anyone’s word”

Same here!

 

[malcolmsanford]

Well I always felt that the HV guys were a spanner short of a set ......................why else would they want to work with big cables and big electricity ..................

But in all seriousness I would imagine that me personally I would only trust myself before plunging my hands into 11kV

 

[Engineer54]

You need to be an ''Authorised Person'' to switch any MV equipment upto 24KV. Above 24KV you also need HV endorsement to your authorisation credentials...

On most modern Ring Main Units, you now have a set of 3 live indication neon's for each incoming cable. Whether this facility was present In this instance we don't know!!! What i don't understand about this supervising Engineer, is that any cable from or too that RMU would need to be grounded if work was going to be carried out on that cable. Therefore the position of the cable ground switch should have been in the grounded position. The switch position of a grounded switch, on all makes of RMUs is very clearly marked and would be instantly recognised as being in that position. You can't ground the cable at the RMU, unless the other end of that cable is also isolated, then both ends of the cable would be grounded. You would NEED to ground the cable no matter what, if it is going to be worked on, as MV and HV cables will act as form of capacitor on long runs holding a significant voltages across the cores.... The other thing that is of concern, is that on all such MV equipment you have an interlocking key system, which only let's you perform switching in logical safe sequences. In this case, it would then need to take a released key from this RMU to the downstream isolation point in order to ground that end of the cable!! This Engineer obviously didn't look at, or check anything!!! Which leads me to believe that this Engineer wasn't in fact an Authorised Person....

Cable jointers working on existing live systems normally check both ends of the cable they are going to be working on to check that the grounding switches are in the ON position, be it via RMU, Switchboard, or Fuse Switch etc... and that lock-offs and notices are in place...

A shambles all round if you ask me!!!

 

[Knobhead]

• Engineer “cut that cable and cap it” pointing to a cable emerging from one end of a trench and vanishing in to the other end.
• Me “f**k off, I want it spiked first”
• “There’s no need, it’s the only cable in the area”
• “Here’s the saw you do it” so the silly sod did, I retreated to a safe distance

I later reported him to the area engineer.

I later became an authorised person

As to PPE the first time I phased out an 11KV feeder I was wearing just a tee shirt and jeans while I crawled inside the OCB cubical to use straight “Hot Sticks”, not the flash protection used now. Even the hot sticks have changed, curved so they can be used from the front of the cubical. I’ve got to admit I didn’t like using them. For those that haven’t come across hot sticks imagine the test prods on your meter 2½’ long with the meter built in to the handle of one probe.

 

[Knobhead]

A shambles all round if you ask me!!!

It shouldn’t be if the HV PTW system is implemented properly.

Problems come when people take short cuts. OK it may take a couple of hours to get the isolations, earthing and paper work in order for a five-minute job, but you’re a long time dead if you get it wrong!

As for cable jointers they are trained to deal with the problems of capacitance, induced voltage and circulating currents. I for one would never cut a cable without bonding jumpers to each side of the cut. New PVC sheathed cables are the worse to work on, as unlike the old hessian serving capacitive charge can’t leak away. The longer the cable the bigger the problem. Distribution companies install a spike at each joint now to try to reduce the problem.

 

[Engineer54]

As to PPE the first time I phased out an 11KV feeder I was wearing just a tee shirt and jeans while I crawled inside the OCB cubical to use straight “Hot Sticks”, not the flash protection used now. Even the hot sticks have changed, curved so they can be used from the front of the cubical. I’ve got to admit I didn’t like using them. For those that haven’t come across hot sticks imagine the test prods on your meter 2½’ long with the meter built in to the handle of one probe.

Trouble is, that these days most MV termination points have been heat shrink booted over a mastic compound. So any Hot stick or phasing stick tests now have to be done prior to any termination booting.

 

[Engineer54]

It shouldn’t be if the HV PTW system is implemented properly.

Problems come when people take short cuts. OK it may take a couple of hours to get the isolations, earthing and paper work in order for a five-minute job, but you’re a long time dead if you get it wrong!

As for cable jointers they are trained to deal with the problems of capacitance, induced voltage and circulating currents. I for one would never cut a cable without bonding jumpers to each side of the cut. New PVC sheathed cables are the worse to work on, as unlike the old hessian serving capacitive charge can’t leak away. The longer the cable the bigger the problem. Distribution companies install a spike at each joint now to try to reduce the problem.

Tony, i don't think this Engineer was an authorised person, far too many things missed from what we've been told, and this jointer didn't do himself any good either by not checking things himself. Hell it must have been plain to both, that the RMU grounding/earthing switch on that cable wasn't in the ON position!!! A shambles it most definitly was!! ...lol!!!

 

[Knobhead]

Trouble is, that these days most MV termination points have been heat shrink booted over a mastic compound. So any Hot stick or phasing stick tests now have to be done prior to any termination booting.

I was testing at the OCB spouts. All the terminal boxes on the gear I worked on were compound filled and so couldn’t be made live until the termination was complete.

Hard luck if the phasing was crossed, you had to melt the box out again. The first placed I worked had various plants with correct and reversed phase rotation on the 11KV, a hangover from the works own generating plant.