HV Authorised Person

[DurhamSparky]

Excellent im now considered one of them now!!! got my letter of Appointment today from work!! learnt some interesting stuff from the tutors on my course (all ex British Steall and DNO workers) with some scary stories and experiences!!

now for one i did not know is if your near a HV breaker and its Hissing at you your actions are to turn and run!! no disconnection no phone calls to the gaffer..... RUN RUN RUN until your at safe distance to make the call..! as explosion is probably not far off!!

 

[rocker]

Barmy!

 

[mechelec]

Have you racked an 11KV circuit breaker in and out of service before? they hiss at you and when they start to hiss I have always been told TURN THE HANDLE FASTER !!!!

 

[DurhamSparky]

not racked a live one in and out thats madness!!

only ones i touched were fixed pattern on 3.3kv!! i got some 11kv ones to play with on site at later date!!

 

[mogga]

well done at getting the Autherised person as for 11kv stuff that for a game I suspect that would make a BIG BANG if it went

 

[rocker]

Theres a video knocking about on here of a poor sod racking a live breaker, getting flashover and ending up a small part of a fireball. I'm not interested in HV at the moment......

 

[Des 56]

Does the license enable you to start your car without ignition

Well done,





When I was apprentice,we had a 11KV compressor motor,scary starting that monster up
It was like an earthquake going on
It seemed like it was measuring 8 on the richter scale

 

[Knobhead]

Run away if you here a hissing sound? Have you isolated a HV breaker? They always hiss as the isolating contacts part. There is no load being broken as the breaker has already done that. It’s just the capacitive charge. If you do run away at that point and leave the contacts hissing there will be a build up of ionised air in the contact spouts, then things get nasty. As mechelec says “turn the handle faster”.

Treat it with respect.

The best courses for HV are run by EMPower they give you practical experience in switching procedures and HV live testing. It’s fun climbing in to a cubical to check 11KV phasing with a “Hot Stick”, NOT!

Since my apprenticeship I’ve worked on 11, 3.3 and 2.5KV systems and seen some hairy stuff. Some pretty stupid stuff as well, on 2 occasions I’ve been there as a “senior authorised person” paralleled 2 main HV feeders via the LV network. On both occasions I was legging it out the door before the switch closed!

1. Learn to prepare switching schedules
2. Have them checked by a second person

If you have any “Dependant Manual” switches on your system operate them “dead” if possible. Otherwise operate them quickly and firmly. DM switches fight back as the contacts close on to load, it’s frightening the first time you do it.

If you PM me I can send you examples of switching scheduals

 

[GrannySmiff]

Well done on that and good luck with it sounds scary, how did you go about becoming autorised, what is the qualification called?.

 

[Knobhead]

Well done on that and good luck with it sounds scary, how did you go about becoming autorised, what is the qualification called?.

Can't find my HV ticket at the moment it's not a formal qualification but an authorisation by the supply authorities for a person to perform switching procedures. Some companies issue limited authorisation for set procedures. Mine covers me to perform and issue switching schedulals

 

[DurhamSparky]

hi tony, i was refering to the hissing sound in the Sub when absoloute no switching is taking place!!
i have some copies of schedules and procedures but thank you very much for offering them, (my company also has pre set ones knocked up by the manufacturer when they commisioned and tested the site.

the qualification was "S4" issued by the Faraday Centre and accredited by EAL and Teeside UNI (they award you with 30 UCAD Points to br used with engineering coursed HNC/D etc)

 

[GrannySmiff]

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that one, it only takes 5 days and you can work with HV? thats crazy. Do you expect to do much HV work, is this all through your company, so you will be going out with experienced people or will you just be sent to the front line?.

 

[DurhamSparky]

we dont do much HV work as we only have 6 subs 4 @3.3 and 2 @ 11kv...! along with 10 gennys as 3.3kv also!

the course is a HV Authorised Person course and is considered a Qualification to allow safe isolation and Restoration of supplies..!

the site i work at is new and all staff are non HV so no experienced guys...! will also be doing the electrical pressure testing course (HV IR) in due time to supplement the AP course!

AT NO POINT WILL WE BE WORKING ON LIVE HV!!!

 

[Knobhead]

Hi Steve

What is the site loading? 10 3.3KV gen sets. Is that plus 11KV external feeds?

 

[DurhamSparky]

Tony,

We have 2x 11kv Incomers to the site Via 2x Transformers, (redundancy etc although we can operate on 1)

this is then utilised to and stepped down to 3.3kv and again to 415v via 4x independant Subs to provide power to our Refrigeration Compound with 7x York Chillers (designed for 8)

our 10 Gen Sets at 3.3kv are 1.8Mw Capacity which can provide power to the FULL site in the event of Incomer A+B Failure (although normal site loading will reduce our 10 Gennys to about 5-6 with 4-5 standby)

we also have 12 UPS 3.3kv/415v Transformers providing our UPS battery backup of 11-12mins

(ups will increase to 24 when phase 2 is built)