Does this violate the UL Listing of the equipment

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bigmack11

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I'm a construction engineer for Lockheed Martin and I'm involved in a project to install two rack mounted Emerson ac/dc rectifier systems in a Telecom environment. The original design called for connecting the DC loads to the individual factory provided 60 Amp breakers. We are now being told by the A&E to use a larger conductor than the system is designed to accept (4/0 vs. 2 AWG) and to also bypass all overcurrent devices and to terminate the 4/0 cu directly to the portion of the buss that is reserved for the battery connections. They are attempting to turn the system into a single 400 Amp output distribution instead of individual branch circuit loads. To even make the connections of the 4/0 cable to the battery buss, the buss will have to be drilled to accept the 3/8" hardware for bolting the double barrel lugs to the buss and there are serious space restrictioins between the +/- buss. (the buss is set up with two 1/4"-20 studs 5/8" OC from the factory. To make things even more crazy, the new rectifier system will be used to feed a remote DC distribution cabinet that supports individual 60 Amp loads. My electricians are telling me that this application of the new rectifiers is not correct and that if we follow the instructions of the A&E, a number of NEC violations will be created (no OCD) and we will void the UL Listing for the
Emerson rectifier system.
Not to mention the hazards that are being created for personnel.

Please provide your opinion on this install that is dangerously off track.

Thank you,
bigmack11
 

iwire

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Staff member
Location
Massachusetts
Here is some info directly from UL, it may help.

Field Modifications
What happens to the Listing if a UL-Listed product is modified in the field?
An authorized use of the UL Mark is the manufacturer?s declaration that the product was originally
manufactured in accordance with the applicable requirements when it was shipped from the factory. When
a UL-Listed product is modified after it leaves the factory, UL has no way to determine if the product
continues to comply with the safety requirements used to certify the product without investigating the
modified product. UL can neither indicate that such modifications ??void?? the UL Mark, nor that the
product continues to meet UL?s safety requirements, unless the field modifications have been specifically
investigated by UL. It is the responsibility of the Authority Having Jurisdiction (AHJ) to determine the
acceptability of the modification or if the modifications are significant enough to require one of UL?s Field
Engineering Services staff members to evaluate the modified product. UL can assist the AHJ in making this
determination.
An exception for a field modification authorized by UL is when the product has specific replacement
markings. For example, a switchboard may have specific grounding kits added in the field. The
switchboard is marked with a list of specific kit numbers that have been investigated for use in that
particular switchboard. Only grounding kits that are included on the marking on the product have been
investigated for use in that product.
If a party wishes UL to determine if the modifications made to a UL Listed product comply with UL
requirements, the appropriate Field Engineering Service can be initiated to investigate the modifications.
This investigation will only be conducted after UL consults with the AHJ to ensure that UL?s investigation
addresses all areas of concern and meets all of the AHJ?s needs.
If you have any questions or would like to inquire about a Field Evaluation, contact Field Services at
+1-877-UL-HELPS, prompt #2 (+1-877-854-3577) or visit http://www.ul.com/field/index.html.
 

hurk27

Senior Member
I would say that not only would you violate the UL listing, but also void any Emerson rectifier system warranty for their system, as well as adding the danger of overloading the system as a whole, if the battery banks are also installed, to this buss, and a fault was to occur, you could have a massive runaway battery melt down on your hands. I would get the manufactures involved with this, and get their stamp of approval before any of this takes place, the liability is just to great.
 

r6ckstar

Member
bigmack - without knowing more details to your situation it sounds more like you have some unqualified people attempting the work. If they aren't trained DC Level 4 technicians I would be worried. As far as the batteries landing on the buss bar they should at the very least have some form of disconnect, however usually fused. Also there should be no need to drill the buss bar, I'm not sure why you'd be using double barrell lugs, however burndy does make a single barrell lug to bolt right up. (Part No. YAV28-L2TC14-FX) Hope this helps.
 
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