Had an experience this summer while using my jig saw. It is a top of the line model ( I won’t say what brand at this time) and while rarely using it for once outside to cut some gingerbread trim for a porch I found I could smell smoke. I stopped at once fearing that the house I was at or a neighbors house was on fire began to reach to get my cell while at the same time look for the cloud of smoke that would indicate the location of the fire. The smell of smoke quickly got stronger and that was when I noticed my extension cord and jig saw connection on fire. Pulling the Extension cord out of the wall and throwing it off the porch to the drive removed any immediate threat. However on further investigation I found that it was a broken male end on the double insulated cord that was the cause. As I said it was on fire. The extension cord I had in use was 25′ and a 14 gauge. I can only consider myself lucky that I chose to do the work outside that day and not in my shop where my cord might have been in closer contact with finer sawdust from my drum sander and cabinet saw.
The question I have for you all is
1) I still have the plug connection since I cut the two cord ends off. What would you do with them? (yes I’m pissed with the supplier but am looking for a sensible approach)
2) I have removed all my molded factory installed ends with higher end plugs. Has anyone else had problems as I described or what do you do to prevent such things from happening ?
Thanks in advance.
Scott T.
Replies
Sounds like you got a defective one. It happens. Even to reputable companies. Also you might suspect the male cord cap on the jig saw. Those male ends are subject to being bent, abused and corrosion. Much more so than the female ends. If you were running the saw pretty much full time for ten minutes or more it wouldn't take much to build up heat.
As part of a job site safety program we used to bring in all the extension cords, when we could pry them away from the carpenters, to test them. We would look them over inch by inch and run them through the hand, unplugged, to find bad spots. If I had time I would hook them into a 12A load I rigged up and check for heat build up by feel. i could check a 100' cord in about 15 minutes. Including the stress test.
All this is probably a little involved for a small time carpenter but you could easily do the same thing. Instead of a rigged load just plug in a circular saw, the dummy load was quieter, and feel the cord caps after a couple of minutes. Hotter they get the worse they are. Sometimes a bit of cleaning or straightening of the male prongs will make thing right. Other times replacement is the only course.
I would take the fried cord end to the store where I got it, a receipt might help, and see if they will spring for another. If so you get a cord for your trouble. If they claim the male plug on the saw or job site abuse were the cause you might have to eat it. You might also try the manufacturers technical or service department. Sometimes you get good people who will go out of their way to make it right. Worth a try.
The only way I know of to prevent this happening in the future would be periodic inspection and testing of your cords. You could also check the saw as a defective saw, or other power tool, might draw enough current to overheat the cord caps even if they were in decent shape.
Have heard horror stories of cords melting into fine wool carpets and such. Burning down the HO's house makes for a poor reference. Insurance. Preparedness. Inspections and an little luck.
You point out an interesting scenario when you mention damage or worse yet, destruction of a clients property due to bad cordage. I'm sure too many of us will keep a cord in service past it's life. New quality ends work better at holding the mating plug end, but still, I imagine that these repairs are on the bottom of the list of preventative maintanence. Thanks for the friendly reminder.
One question. Seems to me I remember something about osha and non moulded plug ends. Hearing somewhere that only moulded were street legal. Any idea on that?Remodeling Contractor just outside the Glass City.
Quittin' Time
I seem to remember hearing that OSHA doesn't want non-factory installed cord ends on a job site. They don't trust us to get the polarity right on replacement ends.
Is 14 ga wire appropriate for your use?
a 100ft long, 14 ga extension cord could be overloaded by a moderately high current draw saw, due to the length.
I ask this because the original poster did not say how long his cord was.
Norm
25
Who ever invented work didn't know how to fish....
Edited 11/11/2003 1:54:17 PM ET by IMERC
I am partial to the 12 guage Yellow Jackets. Tough, yet flexible.
edit: as for length, usually not more than 50'
Edited 11/11/2003 7:46:02 PM ET by Shoeman
I too like yellow jacket cords because they have a lifetime guarantee.
ANDYSZ2I MAY DISAGREE WITH WHAT YOUR SAYING BUT I WILL DEFEND TO THE DEATH YOUR RIGHT TO SAY IT.
I looked at the OHSA website and ran a scan on "molded plugs". Didn't find any comments about them. The following are the sections I found referring to extention cords and flexible equipment cords. There could be lots more there than what I looked at, so if anyone else has a specific reference, I would appreciate getting it.
I don't have the NEC Article 400 or the table 400-4 in my abbreviated NEC book, so was not able to check that.
From: http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10706
1926.405(a)(2)(ii)(I) <owalink.query_links?src_doc_type=STANDARDS&src_unique_file=1926_0405&src_anchor_name=1926.405(a)(2)(ii)(I)>
Flexible cords and cables shall be protected from damage. Sharp corners and projections shall be avoided. Flexible cords and cables may pass through doorways or other pinch points, if protection is provided to avoid damage.
1926.405(a)(2)(ii)(J)
Extension cord sets used with portable electric tools and appliances shall be of three-wire type and shall be designed for hard or extra-hard usage. Flexible cords used with temporary and portable lights shall be designed for hard or extra-hard usage.
NOTE: The National Electrical Code, ANSI/NFPA 70, in Article 400, Table 400-4, lists various types of flexible cords, some of which are noted as being designed for hard or extra-hard usage. Examples of these types of flexible cords include hard service cord (types S, ST, SO, STO) and junior hard service cord (types SJ, SJO, SJT, SJTO).
1926.405(g)(1)(i)(H) <owalink.query_links?src_doc_type=STANDARDS&src_unique_file=1926_0405&src_anchor_name=1926.405(g)(1)(i)(H)>
Appliances where the fastening means and mechanical connections are designed to permit removal for maintenance and repair.
1926.405(g)(1)(ii)
Attachment plugs for cords. If used as permitted in paragraphs (g)(1)(i)(C), (g)(1)(i)(F), or (g)(1)(i)(H) of this section, the flexible cord shall be equipped with an attachment plug and shall be energized from a receptacle outlet.
1926.405(g)(1)(iii) <owalink.query_links?src_doc_type=STANDARDS&src_unique_file=1926_0405&src_anchor_name=1926.405(g)(1)(iii)>
Prohibited uses. Unless necessary for a use permitted in paragraph (g)(1)(i) of this section, flexible cords and cables shall not be used:
1926.405(j)(2) Receptacles, cord connectors, and attachment plugs (caps) -
1926.405(j)(2)(i) Configuration. Receptacles, cord connectors, and attachment plugs shall be constructed so that no receptacle or cord connector will accept an attachment plug with a different voltage or current rating than that for which the device is intended. However, a 20-ampere T-slot receptacle or cord connector may accept a 15-ampere attachment plug of the same voltage rating. Receptacles connected to circuits having different voltages, frequencies, or types of current (ac or dc) on the same premises shall be of such design that the attachment plugs used on these circuits are not interchangeable.
from: http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9882
1910.305(g)(1)(iii) Unless specifically permitted in paragraph (g)(1)(i) of this section, flexible cords and cables may not be used:
1910.305(g)(1)(iii)(A) As a substitute for the fixed wiring of a structure;
1910.305(g)(1)(iii)(B) Where run through holes in walls, ceilings, or floors;
1910.305(g)(1)(iii)(C) Where run through doorways, windows, or similar openings;
1910.305(g)(1)(iii)(D) Where attached to building surfaces; or
1910.305(g)(1)(iii)(E) Where concealed behind building walls, ceilings, or floors.
1910.305(g)(1)(iv) Flexible cords used in show windows and showcases shall be Type S, SO, SJ, SJO, ST, STO, SJT, SJTO, or AFS except for the wiring of chain-supported lighting fixtures and supply cords for portable lamps and other merchandise being displayed or exhibited.
1910.305(g)(2) Identification, splices, and terminations.
1910.305(g)(2)(i) A conductor of a flexible cord or cable that is used as a grounded conductor or an equipment grounding conductor shall be distinguishable from other conductors. Types SJ, SJO, SJT, SJTO, S, SO, ST, and STO shall be durably marked on the surface with the type designation, size, and number of conductors.
1910.305(g)(2)(ii) Flexible cords shall be used only in continuous lengths without splice or tap. Hard service flexible cords No. 12 or larger may be repaired if spliced so that the splice retains the insulation, outer sheath properties, and usage characteristics of the cord being spliced.
1910.305(g)(2)(iii) Flexible cords shall be connected to devices and fittings so that strain relief is provided which will prevent pull from being directly transmitted to joints or terminal screws.
The hard rule has been that factory installed, molded, cord caps are required. In this case a single defect in either cord cap or the cord dooms the entire assembly. In this case I'm forced to cut the cord into lengths too short to be reused.
While I understand the logic behind this, even some otherwise qualified electricians can't, won't or don't know how to install a cord cap properly. This with the background that a disproportionate number of job site accidents, injuries and deaths are associated with the misuse or failure to maintain extension cords.
I find it ironic that an electrician trusted to handle high voltage circuits, area GFCIs that protect people working in knee deep water and circuits in confined spaces with explosive atmospheres are not trusted to handle such a simple job.
Some inspectors, local and OSHA, are less gung ho about these rules if a concerted effort is being made by a group of dedicated, well trained and qualified electricians. Assuming they are well supported in time, authority and material a systematic maintenance and inspection program can make a very substantial difference in how the rules are interpreted and enforced. In my case the general contractor authorized two electricians to inspect, confiscate, bar or, where warranted, destroy, any cords or power tools brought onto the job site.
In this case cord caps were allowed to be replaced as long as the work was done by us and the cord was relegated to dry locations. Any subcontractors cords that had replacement cord caps were carefully inspected and redone as needed. All power tools had to be inspected and tested for current leakage and ground on a regular basis.
All of this is beyond the scope of what makes sense for most builders on anything but the largest projects. On smaller sites it is usually only the factory installed cord caps that are likely to be allowed by the strictest rules. Of course with the general condition of the extension cords being marginal to quite foul I suspect that a well installed cord cap wouldn't raise any great alarm. A simple yearly inspection would be a step up.
and right now, as we speak (or write), osha is tracking you down to do a surprise inspection on all your cords and plugs........ ;-)
m
Thank you.Remodeling Contractor just outside the Glass City.
Quittin' Time
For years I've been religiously cutting off mfgr's moulded cord caps and replacing them with super heavy-duty 'Hippo' caps--at a cost of $20 per cap!--because they're made of extremely high-impact, rigid plastic (ie: they don't become impossible to use in -20 temperatures); and the contacts inside the female caps have two times the surface area of the cheap caps that come moulded on standard-duty cords--thus, they hold the connection much better, and there's much less chance of heat build-up at that point.
I stopped buying standard duty 'orange' extension cords years ago; those that I still have are used only for long-run supply to a relatively fixed position (same as my old el-cheap-o air hoses: the tool is never connected directly to them, but to a better grade hose or extension wire). I'm using them until they die and then they get trash-canned but the Hippo end-caps get transferred to 12 or 14-ga. SJOW, which is my standard for all new cords (12-ga. for 10-30 meters; 14-ga. for under 10 meters).
All portable tools running 3-wire power cords get a hippo plug as a replacement cord cap when any wear or damage is noted. Mfgr-supplied cheap-o, plastic-sheathed power cords are changed out for SJOW of the appropriate gauge AT PURCHASE TIME on all but stationery tools (table saws, compressors, etc.).
What's interesting about your post is that it seems I've been going against your federal safety regulators while in fact what I've been trying to do is improve the standard of safety and durability of one of the most important (and potentially dangerous) items on my small jobsites.
Just goes to show, logic can't predict what the guvmint will come up with.
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
Saw dust is hard to burn.
Put new ends on the damaged cords and get on with your life. (I see you did that.) And get on with your life.
Speaking also as a firefighter it is hard to put out without removing all possible areas of combustion. Everytime you stir it up it flares up with the intro of air. It can also smoulder for hours. SEEN ITS RESULTS
By the way I am not letting life pass me by. It's been 3 months since it happened and I've lost no sleep. I think I may be over it. Wait.... yup I'm over it.
Edited 11/11/2003 8:21:20 PM ET by noitall