RFI 4 Questions and Answers.docx

RFI 4

FA251724Q0029

Medium Voltage DC Power Supply Breaker System

1. The Government's response to question #5 is that the "Contractor shall utilize SetPoint as the Contractor for reconnecting and reprogramming units into the CMSFS BAS". Can the Government please confirm that this should be included in pricing? If so, please provide the point of contact information for SetPoint?

SetPoint Systems is the only contractor that is authorized to work on the Delta Controls Automation system that is in place.

Trey Sellers Account Manager Setpoint Systems Corporation tsellers@setpointsystems.com C: 720.387.1238 | O: 303.733.2300 24/7 Support: 1.800.372.8837 8167 SouthPark Circle, Littleton, CO 80120

2. The Government responded to RFI 1 #3 "SOW line item 1.2.2.3 indicates the function of the new units to be stand alone OR in parallel, please clarify the intended use for either stand alone and parallel." with the answer "The purpose of the system is to charge the batteries. By standalone, they need to be able to handle the load of charging the batteries on that floor. In parallel, they need to be able to charge the batteries on both floors." However, replacing the existing system will not allow both battery cabinets to be charged by only one DC charger/rectifier. If the intent is to truly have either rectifier charge both batteries due to one rectifier failure, then the SOW should be revised.

Can the Government please clarify if it will provide an updated SOW to account for this additional scope?

See the reasoning below for this question based on the excerpted diagrams from the Battery System One-Line drawings provided:

If one rectifier is isolated, that battery is also isolated, even if the DCPA and DCPB load distribution panels are tied together. In order to accomplish this, the batteries must be connected directly to DCPA and DCPB load distribution panels, which would require an additional 200AT breaker to be installed in both panels as it was before the last system update in 2014 according to the electrical drawings provided.

· NORMAL OPERATION:

· Rectifier A charging Battery A and feeding power to DCPA

· Rectifier B charging Battery B and feeding power to DCPB

· RECTIFIER A FAILURE:

· Tie both DCPA and DCPB together

· Rectifier B support both Battery A and Battery B as well as DCPA and DCPB

· RECTIFIER B FAILURE:

· Tie both DCPA and DCPB together

· Rectifier A support both Battery A and Battery B as well as DCPA and DCPB Currently the batteries are only connected to the Rectifiers and isolated from the distribution panels.

The 'Pre-2014 Demo One-Line.png' drawing (attached) shows the one-line drawing before the system was replaced in 2014 with the Always On systems. This configuration would allow one rectifier to support both battery cabinets and both DC load panels.

The 'Current One-Line.png' drawing attached) shows what changes were made in 2014 and how the batteries were moved to each rectifier, limiting the ability for either rectifier to support both battery strings.

The paralleling requirement will be accomplished via the tie between the two respective DC panels. Each DC power supply will be connected to the battery bank, and charge that bank alone, on the same floor as that system.