Customer case |
10 October 2017
SSG has produced SSG 4510 – Guidelines on the Management of Electric Arc Risks, in order to reduce the risk of accidents in connection with electric arcs. The guidelines provide suggestions of tangible measures to enable people to protect themselves and to make the working environment safer in the area of electrical works.
“These are unique guidelines, and there’s no equivalent in Europe,” says Tomas Kristensson, Senior Advisor at SSG.
SSG 4510 has been drawn up by SSG’s Electrical Engineering Committee, together with a working group from Swedish industry, energy companies, manufacturers and suppliers.
“We were a handful of experts who decided 3.5 years ago to take a closer look at the problem of electric arcs, which a lot of people were talking about but no one had studied in any greater detail. We set up a network, which then became a working group within the SSG Electrical Engineering Committee. We gathered a lot of knowledge and material, and in spring 2016 we started the actual task of drawing up the SSG 4510 guidelines on electric arc risks,” explains Tomas Kristensson, Senior Advisor at SSG.
“It’s been an interesting journey, and we’ve learned a great deal ourselves while working on the guidelines,” says another of the people behind the initiative, Lars-Göran Andersson, Maintenance Manager at Essity Hygiene & Health Products and a member of both the SSG Electrical Engineering Committee and the SSG Safety Committee.
People usually talk about two electrical risks in the field of electrical works.
“One is touch voltage and the risk of an electric shock, which we’ve been focusing on for a long time. This has resulted in an everyday environment and a working environment that are now pretty safe. The other risk is the consequences of electric arcs, an area where there hasn’t previously been the same level of knowledge and awareness,” says Tomas Kristensson.
An electric arc in an electrical installation can cause serious injuries and, in the worst case, it can result in death. Between 2000 and 2015 there were around 200 accidents involving electric arcs that resulted in sick leave, one of which had a fatal outcome. Apart from the human suffering, there is a risk of major financial damage in the form of sick leave, damage to property and production stoppages.
The newly-published SSG 4510 guidelines focus on plant owners and electricians, helping them to improve awareness of the risk level associated with electric arcs, and how electricians can best protect themselves.
“The guidelines provide knowledge and tangible suggestions of measures that can reduce the consequences of an electric arc. These are unique guidelines, and there’s no equivalent in Europe,” says Tomas Kristensson.
In its work to produce SSG 4510, the working group went back to basics and studied how a burn occurs and what energy level is required.
“The skin won’t tolerate much energy. If a kitchen hob is only warm, you have time to remove your hand, but if it’s hot you’ll burn yourself before you can pull back your hand.
During our work we reached the conclusion that you must protect the skin by clothing ourselves in layers, just as we do in the cold. So you get better protection with several layers of clothing than with one layer,” says Tomas Kristensson.
This knowledge has caused several manufacturers of protective clothing to react quickly and conduct new tests.
“Since last year, a lot of new, improved protective clothing and protective gloves have appeared,” says Tomas Kristensson.
Another experience of SSG 4510 is that electricians must disconnect the power sooner.
“You can actually calculate the size of the current risk of an electric arc in each switchgear, and as a plant owner you are obliged by law to provide information about this. When an electrician arrives at a switchgear, he or she can determine immediately on the basis of the information available whether his or her own personal protective equipment (PPE) can handle the energy level for the electrical work. If it can’t, he or she must work without current and switch off/lock. We’ve learned to remove the risk by disconnecting the power at a much earlier stage than we used to do. Many people are currently working for far too long with the power on.”
Another safety measure is to take another person with you.
“If an electrician closes the door for safety reasons, there’s often no one else with a key to get into the switchgear. It can then take an eternity to open the door in the event of an accident. For that reason, many electricians want to have someone who is qualified in life-saving with special knowledge of electrical injuries and an alarm with them in the switchgear in case something happens,” says Tomas Kristensson.
Information about the consequences of electric arcs is now an important part of SSG’s electrical courses. There has been a very high level of interest in SSG 4510 from both companies and the Swedish National Electrical Safety Board. Not least of all Tranemo, the protective clothing manufacturer, which has made sure that all of its sales representatives have access to the guidelines, which they now consider to be “the sales representative’s bible”.
At Essity Hygiene & Health, they are planning to make full use of SSG 4510.
“We’ll be focusing not only on switchgears, but also on cabinets for a winder, for example, where the operators usually perform resets. After we’ve informed them about the risks, some operators don’t want to reset any more. It’s easy to believe that it’s one hundred per cent safe if the door to a switchgear is closed, but that’s not the case. It’s never sealed and there’s always an opening for an electric arc to escape through. We benefited greatly from the knowledge acquired while working on SSG 4510 recently when we replaced one of our switchgears. Now that we can actually use facts to show the risks to personal safety, it’s become easier and more natural to make decisions on investments to remove them,” concludes Lars-Göran Andersson, Essity.
