Proposal 11- 104 - (440-65 (New) ): sense leakage currents flowing between or from the conductors of the cord set and interrupt the circuit. If leakage current is allowed to continue
Note: It was the action of the Technical Correlating Committee that this Proposal be reported as "Reject" because less than two thirds of the members eligible to vote have voted in the affirmative.
SUBMITTER: Edward A. Schiff, Technology Research Corp.
RECOMMENDATION: 440-65. Cord Sets with Leakage Current Detection and Interruption Protection
(a) Definition: Cord Sets with Leakage Current Detection and Interruption (LCDI) - a cord set intended to flowing from the conductors, risk of ignition of the surrounding combustible materials and risk of serious injury from electrical shock may result.
(b) All single phase cord and plug connected room air conditioners shall be provided with factory installed cord leakage current detection and interruption protection. The LCDI shall utilize air break contacts and be an integral part of the attachment plug or located in the supply cord within 12 in. (305 mm) of the attachment plug.
SUBSTANTIATION: Electrical cords and plugs are responsible for 7400 fires (attended by the fire service) per year which result in 108 deaths, 539 civilian injuries and $121 million in direct property damage per year in US homes according to The US Home Product Report, 1991-1995
(Appliances and Equipment) published by the NFPA in 1998. The majority of the cord and plug fires were caused by short circuits or ground faults (54.3%). Other electrical failure (23%) and overloads (9.4%) accounted for most of the balance. Following the leadership of the Consumer Products Safety Commission, the electronics Industry Association, AHAM, NEMA, and Underwriters Laboratory, industry has made a significant effort on the development of technologies for improving the safety of electrical products.
The flexible cords on room air conditioners are subjected to excessive abuse during its product life. The power supply cord can be damaged in a number of ways. The cord can be pinched or crimped during installation or storage. The shear mass of the product can permanently damage the cord. Once installed the cord is often within harms way by being pinched by furniture, chewed by a pet or infant or kicked.
This abuse will result in series (broken conductors), parallel (degraded insulation), and/or ground faults in the cord. These conditions will lead to combustion of the cord and/or surrounding material. Examples of recent serious room air conditioner cord fires are contained in table 1 that I have provided. Room and portable air conditioners account for 1,400 fires (attended by the fire service) per year and result in 10 deaths per year, on average according to the NFPA.
Considering that these products are primarily used seasonally in the North East, this would equate to approximately 10 fires per day attended by the fire service (not to mention, all the fires which are controlled without calling 911). In addition, cord damage presents a significant risk of serious injury from shock or death by electrocution. There have also been many incidents of electric shock and even electrocution involving air conditioners. In 1997, an 18-year-old girl was electrocuted in Maryland because a damaged cord was touching the metal frame of her hotel room door. In July of 1999, a seven year old boy in Sabetha, Kansas died from electrocution when he came in contact with a dehumidifier cord on a wet kitchen counter top. Devices which meet this standard sense ground faults, thus providing protection from serious injury from shock or electrocution.
Many precedents exist for incorporating cord LCDI protection for room air conditioners into the code. The safety of service cords has long been viewed as part of the branch circuit wiring by the code for years. Examples include Section 422-49 GFCIs on high pressure spray washers, Section 422-41, Cord and Plug connected appliances subject to immersion (hair dryers), Table 400-4 defining lamp, heater, iron, range, dryer and vacuum cleaner cords, and Article 422 defines a multitude of flexible cord and plug-connected appliance requirements.
A serious safety problem continues to exist. Proven UL recognized / CSA certified cord sets are available from multiple manufacturers which provide this protection at an economical cost. The elimination of these needless deaths is immeasurable and the savings in property losses, injuries, insurance claims, and law suits will be dramatic. Note: Supporting material is available for review at NFPA Headquarters.
PANEL ACTION: Accept in Principle in Part.
Add a new definition to 440-2 as follows:
“Leakage Current Detection and Interruption (LCDI) Protection.
A device provided in a power supply cord or cord set that senses leakage current flowing between or from the cord conductors and interrupts the circuit at a predetermined level of leakage current.”
Add a new 440-65 as follows:
“Leakage Current Detection and Interruption (LCDI). Single-phase cord- and plug-connected room air conditioners shall be provided with factory-installed LCDI protection. The LCDI protection shall be an integral part of the attachment plug or be located in the power supply cord within 300 mm (12 in) of the attachment plug.”
PANEL STATEMENT: The changes are to (1) comply with the NEC Style Manual; (2) include power supply cords; (3) delete the proposed requirement that air break contacts be provided, as being too restrictive and not substantiated.
NUMBER OF PANEL MEMBERS ELIGIBLE TO VOTE: 15
VOTE ON PANEL ACTION:
AFFIRMATIVE: 7
NEGATIVE: 8
EXPLANATION OF NEGATIVE:
BUNCH: There is conflicting data as to actual cause of cited incidents of cord related failures. Although this CDI might lead to a product improvement, it should be regulated through the recognized testing labs and standards, not in the NEC.
COX: Devices, such as proposed, would offer protection of all available portable cord connected devices if they were installed on the branch circuits rather than on individual pieces of equipment. Article 210-12 already provides for similar devices on branch circuits for bedrooms.
HAMER: This should be handled in the product standards, not the National Electrical Code.
RASMUSSEN: The proposal should be rejected. The concept of utilizing advancements in technology to enhance the safety of appliances should be encouraged. However, the submitter's substantiation does not provide clear evidence that the incidents of cord fires cited relate to damage to the room air conditioner supply cord. The involvement of inappropriate extension cords appear to be a factor. For instance, in the Oct. 1998 El Dorado, AR incident, one of the few examples where some detail is given, it states, “The spliced cord was run under a rug across the room, when it overheated and arced.” Before requiring such major change to existing room air conditioner requirements, the submitter is encouraged to provide well documented and verifiable examples of specific incidents where the product improvement being recommended would have prevented the unwanted incident from occurring.
SCHRAM: The information on fires alleged to have been caused by overheating or faults in room air conditioner power supply cords, which was presented to the panel, is vague as to the details of the actual causes of the fires. It is not clear from this material a that a LCDI in the air conditioner power supply cord or plug would have prevented any of the reported fires. The substantiation for the proposal refers to the “excessive abuse” potential for room air conditioner cords, but the material presented to the panel contains no details to support this contention. Further, no data was presented to the panel to support the statements in the substantiation concerning electric shock incidents that could have been prevented by use of a LCDI in the cord or plug. It is my opinion that the NEC is not the proper place for a product safety requirement, such as mandating the factory installation of a LCDI in room air conditioner power supply cords or plugs. I recognize that 422-41 and 422-49 do include similar requirements, but the circumstances that resulted in these code requirements were quite different than the circumstances in this case, and the need was well supported. I would urge the manufacturers of room air conditioners to thoroughly investigate the need for and efficacy of LCDIs on room air conditioners, and if appropriate, revise UL484 to require their use.
SAPORITA: I must vote negative on the panel action. While I believe that this proposal may reduce the likelihood of cord fires, this is a product standards issue.
THOMAS: The cord set with leakage current detection and interruption seems to be a reasonable safety item but I question placing the requirement in the NEC. This is not part of the premises wiring and is not enforceable by the Authority Having Jurisdiction.
WRIGHT: The proposal should be rejected. NEMA agrees with the submitter's concept. However the proposal is too restrictive.
There are other methods of providing this protection.
I understand that it is supposed to detect leakage current from a hot to ground short in the line cord if it's damaged. I would like to know what idiocy mandated a device like that.
