I've got a question for everyone that does electrical work or inspections in commercial automotive repair garages.
Here is the NEC reference I am concerned about applying (bold added):
511.4 Wiring and Equipment in Class I Locations. (2) Portable Lighting Equipment. Portable lighting equipment shall be equipped with handle, lampholder, hook, and substantial guard attached to the lampholder or handle. All exterior surfaces that might come in contact with battery terminals, wiring terminals, or other objects shall be of nonconducting material or shall be effectively protected with insulation. Lampholders shall be of an unswitched type and shall not provide means for plug-in of attachment plugs. The outer shell shall be of molded composition or other suitable material. Unless the lamp and its cord are supported or arranged in such a manner that they cannot be used in the locations classified in 511.3, they shall be of a type identified for Class I, Division 1 locations.
The 2002 Handbook goes on to say:
The Class I, Division 2 location above grade within a commercial garage extends 18 in. above floor level, unless the authority having jurisdiction determines otherwise because mechanical ventilation provides at least four air changes per hour. The Class I, Division 1 location below grade extends from the floor of the pit or depression to floor level, unless the authority having jurisdiction permits the pit or depression to be classified as Class I, Division 2 because ventilation providing at least six air changes per hour exhausts air at the floor level of the pit or depression. Areas suitably cut off and areas adjacent to unclassified, ventilated garages are not classified as hazardous.
OK. Now for the question. Have any of you actually installed (or in the case of inspection) required the installation of this equipment?
It has been my experience that rarely do garages have the required air changes, especially in the cold weather climate of Ohio, where the ventilation is turned off in the winter to conserve heat.
Everytime I bring up this requirement... no one has ever heard about it, even though it has been in the NEC for several years. This includes the people selling the handlamps, who only seem to carry or push equipment that is not in compliance. Does anyone know of a compliant handlamp that is not over $400?
Comments, concerns, suggestions.
Edited to add bold to NEC reference.
[This message has been edited by safetygem (edited 02-15-2005).]
I agree with I-wire. The code here is worded as an engineer (who thinks he's also a lawyer) would write it...trying to legislate "best" rather than "minimum." I believe that Oliver Wendell Holmes was the US Supreme Court justice who observed "the law is an ass." With all of the other hand-lamp problems (electrocutions, fires, etc), I doubt that you're ever going to see $400 lamps used.
It should also be pointed out that the Class 1 area is only close to the floor...since the introduction of hydraulic lifts, it's been quite a while since I've seen a mechanic use a floor creeper. I don't expect that the lamps enter the "classified" area very often.
Re: Commercial Garage Handlamps#91981 02/16/0512:32 AM02/16/0512:32 AM
This is something that I wondered about for a bit. For a auto shop what class the location would fall into. I never seen anything special used as far as lighing fixtures, outlets, switches, etc. I don't know if I seen a shop yet with a GFI.
The drop lights are pluged in after the fact. I don't think the electricin has much say after he leaves.
The A-bulb is slowly being replaced by the mini florescent which is safer. The A-bulb drop light gets hot with a 75 or 100 w bulb. you get your arms in a tight space with the light and it a matter of time before you burn your self. It will burn the carpet and some plastics.
You never want one of those a-bulb lamps around when working with fuel. I remember once changing a fuel filter but needed to see better. Kept the light hooked on the frame far away. Fuel started running down the frame twords the light. Went to grab it but it fell next to the catch pan. Some gas drip on it and it was all over in a few seconds.
I don't know the flash pionts but I would guess the bulb does not get hot enough to ignight a vapor. I believe cold fuel or solvent hitting a hot bulb could cause the glass to break and start a fire.
Drop lights do end up on the floor all the time. They fall, used as extension cords, or just not put away.
I seen lots of small car and shop fires but I can only think of the one time it was caused by a drop light.
Re: Commercial Garage Handlamps#91982 02/16/0512:37 AM02/16/0512:37 AM
I don’t get to come to this site too often, but I still learn a bit every time I do. This time I’d like to share.
First let me say I agree with the general assessment; however, unless there is substantive change in the definitions of classified locations, this won’t change.
There are several problems; the most serious is that where locations are classified they are usually over-classified and then everyone spends a lot time and effort trying to avoid actually complying with the classification. Classifying them correctly in the first place would be a good start. Often folks just scratch their heads and muddle through.
There is an additional problem with installations covered by Articles 511 through 516. These Articles are generally compelled to coordinate with other Standards that don’t report to the NFPA through the NEC TCC. The folks that define the Classification limits for those Standards are following their interpretation of Section 500. 5 and they tend to be overly conservative – “just to be safe.” (This is why areas get over-classified in the first place.)
The problem with the 500.5 classification definitions is that they are actually based on “possibility” rather than “probability.” However, if they were based on “probability” they would usually take far more time to analyze and be much more difficult to enforce.
500.5 (B) … (1) A Class I, Division 1 location is a location … (1) In which ignitible concentrations of flammable gases or vapors can [not do] exist under normal operating conditions, or
… (2) A Class I, Division 2 location is a location … (1) In which volatile flammable liquids or flammable gases are handled, processed, or used, but in which the liquids, vapors, or gases will normally be confined within closed containers or closed systems from which they can [not will] escape only in case of accidental rupture or breakdown of such containers or systems or in case of abnormal operation of equipment …
A problem with both definitions is that “normal” is not defined as it applies to classified locations.
The original IEC Definitions for Zones are: Zone 0 is: An area in which an explosive gas atmosphere is present continuously or for long periods. Zone 1 is: An area in which an explosive atmosphere is likely to occur in normal operation. Zone 2 is: An area in which an explosive atmosphere is not likely to occur in normal operation and, if it does occur, is likely to do so only infrequently and will exist for a short period only.
These definitions are all “probability” defined. While it isn’t specifically required it is common practice for many to use a logarithmic scale: 1000hr/yr+ is Zone 0, 100hr/yr+ is Zone 1 and 10hr/yr+ is Zone 2.
IEC also defines “normal” as: “The situation when the equipment is operating within its design parameters.” These are like FPNs:
1. Minor releases of flammable material may be part of normal operation. For example, releases from seals which rely on wetting by the fluid which is being pumped are considered to be minor releases. 2. Failures (such as the breakdown of pump seals, flanges gaskets or spillages caused by accidents) which involve urgent repair or shut-down are not considered to be part of normal operation.
Art 505 Definitions “force-fit” the IEC definitions into the “more familiar” NEC format.
Section 500.8(A)(5) says: “Unless otherwise specified, normal operating conditions for motors shall be assumed to be rated full-load steady condition.”
In other words, starting a motor in a Classified location isn’t “normal” per the NEC.
Another difference is that IEC uses area classification to determine other than electrical installations. NFPA 497 reserves it for electrical installations only.
There are several other differences, which is why 505 still needs a “PE” to apply it.
This was all to say that unless there is some serious redefinitions and coordination there will always be what appear to be oddball situations.
[This message has been edited by rbalex (edited 02-16-2005).]
[This message has been edited by rbalex (edited 02-16-2005).]
Re: Commercial Garage Handlamps#91983 02/16/0507:53 AM02/16/0507:53 AM
All I can say is, I had a very good friend that suffered burns over about 30% of his body becasuse of an A lamp and an extension cord type hand held light. The bulb broke and ignited the gasoline on the floor. He lost the car and the garage. This was a residential setting and a homeowner garage so we don't often have any control over what happens in this setting. The hazzard does exist and the code is minimum. If the electrician needs to pay several hundreds or possible thousands of dollars to buy tools to work in his trade, so should any other trade buy the proper tools for his/her trade. I'm kinda glad my dentist don't skimp on tools
I am sorry about your friend but the hazard was the gasoline on the floor, not the lamp. Anything could have started that fire.
Greg You are right of coarse but the principles of fire protection and burn injury prevention are that you can mitigate the fuel, the ignition source, or devise a reliable means to keep them separated. In an auto repair shop it is not logical to act on the idea that all fuel spills can be prevented. Since it is impractical to mitigate the fuel source and the mechanics must have light to work that leaves the ignition source as the only point were mitigation will be effective.
The code forbids the use of exposed incendive lighting in the area were gasoline vapors are likely to be. I've been in Fire and Rescue for over thirty years now and I have seen a few ignition sources that I never would have thought of as likely. In San Francisco, one foggy still night, a car with a damaged gas tank caused enough vapor to accumulate at the bottom of the hill it was sitting on to support the propogation of a back flash that ignited the leaking fuel at the car. The best guess as to the ignition source was the gas light eight feet above ground but four feet below the leaking car vertically.
Gasoline is some weird stuff. In still air it's vapors flow like water and will accumulate in any low spot to form a flammable fuel air mixture. The best answer is probably the use of non incendive rather than explosion proof lights. I do realize that the present code does not recognize that approach. -- Tom H
[This message has been edited by tdhorne (edited 02-16-2005).]
"This alternating current stuff is just a fad. It is much too dangerous for general use" Thomas Alva Edison
I wonder what the insurance report would say ?? "Owner failed to control gasoline spillage in a Class I Div 1 location when the mechanic was using an A lamp hand held light or grinding"?? Owner was at fault.