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Re: NEON- Secondary Ground Fault Protection - Rebuttal
I will not take time or space to repeat Eric's arguments. I have been involved
with the changes to NEC 600 and serve on UL's Industry Advisory Panel. There
appear to be several misconceptions being communicated over this issue.
1. The NEC has introduced a requirement for secondary protection.
2. Allanson has a product line with a type of secondary protection integral to
the units.
3. Allanson's product has been listed in the past by UL. The listing had to be
performed under one of their standards and as a ferro magnetic transformer I
would assume that it was evaluated under UL 506, Specialty Transformers. During
evaluation, notice would have been taken of the protection circuitry, but the
standard had no criteria for evaluating performance. UL's only evaluation of
the protection features would be as to their impact on the safety or application
as a standard transformer IAW UL 506.
4. With the 1996 revision to NEC, UL has announced that compliance of
transformers to the NEC requirements will be evaluated within a new standard UL
2161 (which has not been issued to date). Any transformer which is submitted
for evaluation within the requirements of the 1996 NEC will have to comply with
UL2161.
What UL is saying is that the addition of the NEC secondary protection clause
has resulted in their reviewing existing standards and determining that
sufficient criteria do not exist to fulfill UL's role as a listing agency to
insure product safety. No transformer is required to be submitted to UL2161.
However, after a phase out period, UL 506 and UL 1012, Power Units Other Than
Class 2, will cease as viable standards for transformers and power supplies for
discharge tubing. Any transformer which provides secondary protection must be
submitted and pass evaluation under UL2161 standard. This position only makes
sense. Until UL2161 is published, UL's position is that there is no transformer
"listed" for secondary ground fault protection. Since it is their listing, I
don't see who can argue with their position.
Allanson has a product line with secondary protection, but that protection has
not been specifically evaluated for that purpose. Allanson has not identified
any other listing authority which has come forward and specifically stated that
the product is adequate to meet the NEC requirements. It is not the
responsibility of the NEC or the manufacturer to verify this claim! It is the
function of the third party listing authority to stake out that position.
5. The statement that the Allanson product meets applicable UL standards is
ignoring that UL has stated on numerous occasions that the standard as applying
to secondary protection has not been published and therefore compliance can not
be determined at this point in time!!!! This does not necessarily mean that
Allanson's product will not qualify under UL2161 once it is published. But it
also means that it has not currently complied with the requirements to date.
6. Article 90-4 does permit an AHJ to continue to apply the previously approved
NEC if a product does not exist which complies with the more recent code. Most
AHJ's will waive mandatory compliance if only one source of the product in
question exists. NEC is not in the business of creating monopolies. Allanson
has a product with protection for the secondary circuits. Feel free to use it.
Do not expect the local AHJ's to require that you use it. And when UL 2161 is
published, Allanson's products, just as the product of all other transformer
manufacturers will have to be evaluated against the new standard for compliance
y to the NEC requirement.
7. There is a different problem with which to be concerned. Recently, we
installed a new border application using the Allanson product per the customer's
specification. I went to great length to insure that the installation met
Allanson's requirements. Our installation crews were complimented by Allanson's
engineers when they visited the installation for having met their standards
precisely. The reason for their visit? The transformers would not burn! I am
not criticising Allanson's product, they were able to get the transformers to
work after changing out filters on the protection circuit. The problem is that
after doing everything right (at least by Allansons instructions and admission)
the GFI protected transformers did not perform. Our industry is kidding itself
if we think the new NEC requirements arn't going to create major, major
problems.
Tim Cummings
cent@interserv.com
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