Amendment_2_W911N2-16-Q-0011.pdf

Amendment #2 W911N2-15-Q-0011

Posting of Questions & Answers

Please note that the due date for responses has changed. Responses are now due 28 DEC 2015 10:00 A.M. Eastern Standard Time and the period for questions has closed.

Question Number #2: Probably at the fore is to ask whether we will be permitted to provide a TVSS rated to 400kA/phase per section 1.1.11. I am prepared to articulate the rationale and technical merits to this should this be requested. The section appears to address a service entrance or main service requirement, and would allow a 400kA/phase rate TVSS for the first part of the requirement. The section references a 355kA/phase device in the first part, something with which the 400kA/phase device we will supply complies, in fact exceeds. The second part requires a 655kA/phase device, and it is in this area that we wish to propose a 400kA/phase device rather than the 655kA/phase device mentioned. Suffice it is to say, this is standard practice in the industry.

Answer Number #2: As for the first part of the question; the 400ka would be acceptable for the 355kA (335kA in the purchase description) requirement. However, we need to stay with the 665kA requirement due to the sensitivity of the equipment. A deviation from the required specification is not acceptable because the requirement was set according to the equipment the units will protect. No diagrams will be provided because it is a sensitive operation.

Question Number#3: While we can and will provide 12 of these devices if needed, we anticipate that there is more than a service entrance requirement. The specification references a requirement for 12 units in section 1.1.2. Note that there could be 12 points of protection, and there may be less. To this end I'd like to ask whether an electrical one line diagram exists that specifies the type of device required at each point. Another reason that this is important is that section 1.1 also references 120 volt requirements, typically second level devices.

Typically, we would anticipate that the main service requirement is 277/480 volt with a neutral, or 480 volt no neutral, and then there will be second level devices required at 120 volt or other voltages. Again, here a one line diagram will be useful. This will also clarify the precise number and voltage of TVSS required. Clearly, this is important information.

Answer Number #3: There are different points of protection, but only 1 unit will be required for 480v/1 million amps of protection and 7 units of 120/208V 355,000 amps of protection. The 12 units described in 1.1.2 is an estimation. Please detail your quote per unit. Due to the sensitivity of the operation, no diagram will be provided.

Question Number #4: Section 1.1.1- We have models for all voltages, but we need to know the specific voltage of the electrical panel that you want to protect. Higher peak surge current units are typically installed on service entrance panels, with smaller units (with a lower cost) being installed inside the facility.

Answer Number #4: Section 1.1.1 - We need to have 1 unit to protect 480v with 1 million amps of protection at the main distribution panel and approximately 7 units to protect individual equipment points with voltages ranging from 480v to 120/208v and 355,000 amps of protection.

Question Number #5: Section 1.1.3 - No surge suppressor is designed to explode. But, if you are going into an explosive environment, then do you want the SPDs installed inside an explosion proof enclosure?

Answer Number #5: Section 1.1.3- The units must implode not explode. The units that do not implode actually do explode if a surge is taken. We do not want a unit installed in an explosive proof box when imploding units are available on the commercial market.

Question Number #6: Section 1.1.10 - Where did this requirement come from? There is nothing in UL, IEEE or Nema that sets any minimum component requirement for the size of the MOVs. Indeed, what matters is the strength of the finished product. On what manufacture's product was this section based? This seems like a sole source specification. Can we get an exception from this section?

Answer Number #6: Section 1.1.10 – Current market research indicates that these requirements can be fulfilled by at least two or more commercial vendors. This exception will not be authorized.

Question Number #7: Section 1.1.11- Is the switchgear to be protected rated at over 500kW or over 2500KW?

Also, 90 percent of all SPD manufacturers have listed products that only go up to 400kA per phase. Do you really want 600kA per phase? Can we get an exception from this 600kA requirement? Most mfg only add the components, and there is no independent test certifying that the completed SPD can actually achieve 600kA/phase- 300kA/mode peak surge current.

Answer Number #7: Section 1.1.11 –We require 665kA per phase due to the sensitive equipment that is being protected. An exception for this will not be authorized.

Question Number #8: Are there electronic loads in the facility? If sub panel SPD units are desired, then I suggest that you consider adding a filtering requirement to address the high frequency ring wave transients created by operation of equipment within the facility.

Answer Number #8: The equipment is located inside the facility that will cause the electronic load. This is very sensitive and very expensive unique industrial equipment. An exception for this will not be authorized.

Question Number #9: Finally, how many total electrical panels are to be protected, and what voltages are they at?

Answer Number #9: Please refer to answer #7; in regard to Section 1.1.11 for the answer.