P09 - Att 14 _West Roxburry Electrical Background and Noise Study.docx

1.0 Electrical Power Evaluation and Design.

Background: West Roxbury campus use 4.16 KV at the switch gear building which were transformed from 23.9 KV from the utility. From switch gear building will then transform to 480V for each building. The switch gear building #70 is located near spring street entrance which could possibly be the normal power source for new MCR. The following 2 locations could be the potential options for future TR towers: Building #2 consists of 2 normal power with 2500A and 1200A on secondary bus; Building #1 consists of 2 normal power with 1200A each on secondary bus.

Evaluate existing electrical and power distribution systems, perform the required tasks noted below, provide recommendations, and provide a design for the items noted herein. (Note that field work related to this effort is included in Task 3.3.1):

Provide an evaluation (load, coordination, short circuit, redundancy, etc.) for the existing 4.16kV service, loop and tie into existing loop based on the added data center and mechanical equipment loads. Provide investigations, evaluations, recommendations, and design for a normal power distribution system to support a TIER 3 data center. Provide survey, recommendations and design for the data center equipment electrical systems, panel board, bus system and branch circuit distribution. Evaluation shall include new location(s) for the substation transformers, duct bank, manholes, feeders, rated barrier, and site security. New substation transformers will require an outdoor location, new duct bank, new primary conductors, new primary switches, new secondary conductors, new fire rated barriers and security provisions in accordance with VA criteria.

The existing emergency power system consists of two emergency generators for building #2 with each sized at 600KW and 750KW, two emergency generators for building #1 with each sized at 600KW. Investigate and evaluate the emergency infrastructure and provide recommendations and design for an emergency distribution system that will support a TIER 3 data center. Design work shall include, but it not limited to, the following: new duct bank, manholes, structural pads, storage tanks, stack, foundations, stairs/platforms, fire alarm, lighting, site security with an upgrade to existing emergency system.

Generator(s) design shall comply with the State of Massachusetts emissions control; dispersion exhaust modeling; exhaust stack design (architecturally compatible with the site); and VA requirements. The facility standard for emergency generators is a generator in free standing, weatherproof, acoustical enclosure with diesel fuel belly tank. Design shall comply with the VA security design guide.

Emergency electrical work shall include the removal of the existing 75KW UPS and batteries, and electrical connections located at the basement of building #2 New UPSs shall be provided at the freestanding enclosure to meet the TIER 3 redundancy requirements.

Provide short circuit analysis, arc flash analysis and electrical coordination for the new equipment. Provide new building ground system, lightning protection system, surge protection system.

Submit recommendations for the generator size and recommended location with the 10% Design Submittal. Submit the results of the Electrical Power Evaluation and Design, including recommendations for upgrades required to comply with the VA design criteria for a TIER 3 data center, in the Design Analysis Report submitted with the 35% Design Submittal.

2.0 Noise Emission Study.

Measure and review baseline noise levels. Provide base line ambient sound level measurements at the location near MCR, TR Towers and CRAC:

The intended objective is to assess the potential impact of operational noise from the new equipment on affected activities and interior building spaces (offices, in-patient rooms, clinics, etc.). Utilize the Noise Criterion (NC) curves, to identify desirable limits of background noise for different interior spaces. Sound measurements performed at interior locations shall be compared to the applicable NC Levels for the applicable type of room.

Ambient sound level measurements shall be performed using instruments that meet ANSI S1.4- 1983 standards for Type 1 sound level meters and that possess real-time frequency analysis capabilities (e.g., the Larson Davis Model 831 or 824 sound level meters, or equivalent). The sound level meters shall be programmed to sample and store A-weighted sound level data including equivalent sound levels (Leq) and percentile levels (Ll , LI O, L33, L50, L90, and L99). The frequency content (in octave bands) of the existing acoustic environment shall be sampled and stored to determine compliance.

A-E shall utilize up to five (5) monitors to collect simultaneous ambient sound level data for a minimum period of 160 continuous hours at each measurement location. Ambient sound levels shall be sampled and stored for time intervals of no more than I -hour in duration. Except during periods of deployment and retrieval, the intent is to leave the monitors unattended (that is, no observer will be present) at each measurement location.

To the extent possible, the compliance noise measurement program shall be scheduled for periods with forecast weather conditions suitable for sound level measurements (i.e., no precipitation, low wind speeds, etc.). Monitor the weather forecast for the area prior to deploying the equipment. Construction documents shall require the contractor to provide post-construction compliance noise measurement survey. Perform operational noise measurements at the same locations that will be utilized during the pre-construction measurements using instrumentation with the same technical specifications. Utilize data to develop noise abatement strategy for the new equipment to include operational restrictions. Submit a Noise Study Data Summary with the 10% Design Submittal. Submit the Final Noise Study Memorandum including recommendations with the Design Analysis Report submitted with the 35% Design Submittal.