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 Post subject: De facto standard and IEC Standard
PostPosted: Wed Jun 03, 2009 4:14 am 

Joined: Wed Jun 03, 2009 3:43 am
Posts: 10
In some European countries optical sensor based protection (detection of arc-flash light + possibly combining the detection with instantaneous overcurrent information) is de facto standard. This means that practically all new HV/MV substations are equipped with dedicated arc-flash protection relays or numerical relays with arc-flash option. Retrofit installations are very common, both in utility and industrial installations (MV, LV).

"Rapid fault-clearance times initiated by detectors sensitive to light" is recognised by IEC Standard 62271-200 (Switchgear standard), which lists some other alternatives as well.

According to my observations, in Europe the emphasis lies not only on arc-flash safety (protection of personnel). Motivation to install arc-flash protection comes sometimes from intentions to mitigate or prohibit damage to equipment and to save important processes.


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PostPosted: Wed Jun 03, 2009 2:24 pm 
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Location: Scottsdale, Arizona
That is great information. Thanks for sharing it on the forum.

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Jim Phillips, P.E.
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PostPosted: Wed Sep 02, 2009 5:44 pm 
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Joined: Sun Jan 04, 2009 5:00 pm
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Location: Louisville, KY
EU Arc Flash

Thanks for the mention of this standard. These systems are more common in the EU and I have seen utilities and others installing retrofit systems in the US too. But incidents still happen because this is not always retrofitted on all equipment so legacy systems still exist and even these systems can fail.

Another standard common practice in EU facilities since about 1991 has been the practice of separation of supply and control voltages. In Australia this is VERY common among the utilities reducing arc flash risk without exotic systems.

Another common EU practice is making electrical systems "touch safe". This is also little cost if applied when initially installed and reduces shock and arc flash appreciably. I think these are probably of more consequence that optically based safety systems though these can be very effective.

Recently one guy in England noted that they only had 20 electrical fatalities in England all last year. That surprised me but he claimed the equipment changes in installations since 1991 mentioned above had eliminated a lot of arc flash and shock deaths. Need to check this but it was encouraging


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PostPosted: Sun Sep 13, 2009 2:42 am 
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Joined: Mon Jul 09, 2007 11:43 pm
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Location: Sheffield, England
Recently one guy in England noted that they only had 20 electrical fatalities in England all last year. That surprised me but he claimed the equipment changes in installations since 1991 mentioned above had eliminated a lot of arc flash and shock deaths. Need to check this but it was encouraging

Its true that we have an extremely good and proud record in Electrical Safety in the UK and I would like to think that it goes further back than 1991. Finger safe equipment is the norm and I know that Jim Phillips when he was here earlier in the year was very impressed with the standard of specification of equipment. Jim was the main speaker at the arc flash conference in Watford and another speaker was a Principle Specialist Electrical Engineer for the HSE (Enforcing Authorities) One thing that he commented on was how similar the justification for live work to proceed was. In the UK the relevant regulation is;

Regulation 14 of the Electricity at Work Regulations 1989 which says gives that three conditions must be met for live work to be permitted. These conditions are as follows so judge for yourself:

No person shall be engaged in any work activity on or so near any live conductor (other than one suitably covered with insulating material so as to prevent danger) that danger may arise unless –
a) it is unreasonable in all the circumstances for it to be dead; and
b) it is reasonable in all the circumstances for him to be at work on or near it while it is live; and
c) suitable precautions (including where necessary the provision of suitable protective equipment) are taken to prevent injury.

The culture now is that it is very difficult to justify and live work in industrial and commercial premises with the exception of live diagnostic testing and commissioning. If fact the disturbance or removal and replacement of live components is almost non existent outside the utility companies.

We are not complacent however and still have several hundred burn injuries. I for one am very keen to learn from the work that has been done in the States to predict electrical arcing. We had members in the seminar audience that Jim spoke at who had experienced arc flash and one member wrote to say that he nearly died from an incident.

The key for me is to continuously learn (from each other) and adopt a culture of dead working (placing in an electrically safe condition). It is then absolutely right to give the worker as much information and protection against those situations when live working cannot be avoided.


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