\n\tWhen I think of using PPE as a controls engineer, I think
\nabout electrical shock and arc-flash safety in working with electrical devices. <\/p>\n
The PPE (Personal Protective Equipment) requirements to work on live electrical
\nequipment is making doing commissioning, startup, and tuning of electrical
\ncontrol systems awkward and cumbersome. We are at a stage where the use of PPE
\nis now required but practice has not caught up with the requirements. While
\nmany are resisting this change, it seems inevitable that we will need to wear
\nproper PPE equipment when working on any control panel with exposed voltages of
\n50 volts or more.<\/p>\n
With many electrical panels not labeled for shock and arc-flash hazard levels,
\nthe default PPE requires a full (Category 2+) suit in most cases, which is very
\nawkward indeed. What can we do to allow us to work on live equipment in a safe
\nmanner that meets the now not so new requirements for shock and arc-flash
\nsafety? <\/p>\n
Increasingly the thinking is to design our systems for shock and arc-flash
\nsafety. Typically low voltage (less than 50 volts), 120VAC, and 480 VAC power
\nwere often placed in the same control enclosure. While this is cost effective,
\nit is now problematic when wanting to do work on even the low voltage area of
\nthe panel. The rules do not appear to allow distinguishing areas of a panel as
\nsafe, while another is unsafe. The entire panel is either one or the other. One
\ncould attempt to argue this point, but wouldn’t it be better to just design our
\nsystems so that we are clearly on the side of compliance?<\/p>\n
Here are my thoughts to improve electrical shock and arc flash safety by
\ndesigning this safety into electrical control panels. <\/p>\n
1. Keep the power components separate from the signal level components so that
\nmaintenance and other engineers can work on the equipment without such hazards
\nbeing present. That’s the principle. What are some ideas for putting this into
\npractice? <\/p>\n
2. Run as much as possible on 24VDC as possible. This would include the PLC’s
\nand most other panel devices. A separate panel would then house only these shock
\nand arc-flash safe electrical components. <\/p>\n
3. Power Supplies could be placed in a separate enclosure or included in the
\nmain (low voltage) panel but grouped together and protected separately so that
\nthere are no exposed conductors or terminals that can be reached with even a
\ntool when the control panel door is opened. <\/p>\n
4. Motor Controls running at anything over 50 volts should be contained in a For example “finger safe” design does not meet the requirements for arc-flash \n\tWhen I think of using PPE as a controls engineer, I think The PPE (Personal Protective Equipment) requirements to work on live electrical With many electrical panels not labeled for shock and arc-flash hazard levels, Increasingly the thinking is to design our systems for shock and arc-flash Here are my thoughts to improve electrical shock and arc flash safety by 1. Keep the power components separate from the signal level components so that 2. Run as much as possible on 24VDC as possible. This would include the PLC’s 3. Power Supplies could be placed in a separate enclosure or included in the 4. Motor Controls running at anything over 50 volts should be contained in a For example “finger safe” design does not meet the requirements for arc-flash
\nseparate enclosure. Try remoting the motor controls away from the power devices
\nwhere possible. This includes putting the HIM (keypad) modules for a VFD
\n(Variable Frequency Drive<\/a>) for example on the outside of the control panel, so
\nthe panel does not have to be opened. Also, using the traditional MCC (Motor
\nControl Centers) enclosures is looking increasing attractive to minimize the
\nneed for PPE equipment. <\/p>\n
\nsafety. Also making voltage measurements to check for power is considered one
\nof, if not the most hazardous activity as far as arc-flash goes.<\/p>\n","protected":false},"excerpt":{"rendered":"
\nabout electrical shock and arc-flash safety in working with electrical devices. <\/p>\n
\nequipment is making doing commissioning, startup, and tuning of electrical
\ncontrol systems awkward and cumbersome. We are at a stage where the use of PPE
\nis now required but practice has not caught up with the requirements. While
\nmany are resisting this change, it seems inevitable that we will need to wear
\nproper PPE equipment when working on any control panel with exposed voltages of
\n50 volts or more.<\/p>\n
\nthe default PPE requires a full (Category 2+) suit in most cases, which is very
\nawkward indeed. What can we do to allow us to work on live equipment in a safe
\nmanner that meets the now not so new requirements for shock and arc-flash
\nsafety? <\/p>\n
\nsafety. Typically low voltage (less than 50 volts), 120VAC, and 480 VAC power
\nwere often placed in the same control enclosure. While this is cost effective,
\nit is now problematic when wanting to do work on even the low voltage area of
\nthe panel. The rules do not appear to allow distinguishing areas of a panel as
\nsafe, while another is unsafe. The entire panel is either one or the other. One
\ncould attempt to argue this point, but wouldn’t it be better to just design our
\nsystems so that we are clearly on the side of compliance?<\/p>\n
\ndesigning this safety into electrical control panels. <\/p>\n
\nmaintenance and other engineers can work on the equipment without such hazards
\nbeing present. That’s the principle. What are some ideas for putting this into
\npractice? <\/p>\n
\nand most other panel devices. A separate panel would then house only these shock
\nand arc-flash safe electrical components. <\/p>\n
\nmain (low voltage) panel but grouped together and protected separately so that
\nthere are no exposed conductors or terminals that can be reached with even a
\ntool when the control panel door is opened. <\/p>\n
\nseparate enclosure. Try remoting the motor controls away from the power devices
\nwhere possible. This includes putting the HIM (keypad) modules for a VFD
\n(Variable Frequency Drive<\/a>) for example on the outside of the control panel, so
\nthe panel does not have to be opened. Also, using the traditional MCC (Motor
\nControl Centers) enclosures is looking increasing attractive to minimize the
\nneed for PPE equipment. <\/p>\n
\nsafety. Also making voltage measurements to check for power is considered one
\nof, if not the most hazardous activity as far as arc-flash goes.<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[67],"tags":[],"class_list":["post-14006","post","type-post","status-publish","format-standard","hentry","category-iacdrive_blog"],"_links":{"self":[{"href":"http:\/\/iacdrive.com\/index.php?rest_route=\/wp\/v2\/posts\/14006","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/iacdrive.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/iacdrive.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"http:\/\/iacdrive.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=14006"}],"version-history":[{"count":0,"href":"http:\/\/iacdrive.com\/index.php?rest_route=\/wp\/v2\/posts\/14006\/revisions"}],"wp:attachment":[{"href":"http:\/\/iacdrive.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=14006"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/iacdrive.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=14006"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/iacdrive.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=14006"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}