Attach 2a. - B1041 Final Design Analysis Report.pdf

Repair Fuel System Generators B1041 – Design XDAT 14-1031

Design Analysis, Equipment Cut Sheets

Final Submittal – March 27, 2019

Prepared For:

Travis Air Force Base, California

Prepared By:

2020 E. 1st Street Suite 525 Santa Ana, CA 92705

714.689.0298 Ι www.DevelopmentOne.net

Repair Fuel System Generators B1041 – Design XDAT 14-1031

Final Submittal – March 27, 2019

Tab 1

Under Separate Cover

Design Analysis

Specifications

Equipment Cut

Sheets

Tab 3

Design Analysis – 1

Repair Fuel System Generators - B1041 Final Design Submittal

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1.0

1.1

1.2

2.0

INTRODUCTION

The existing generators are located at Buildings B1041 at Travis AFB, CA. The generators are used as backup power for POL storage and dispensing facilities. The generators are mission critical and required to ensure continuation of mission capabilities during any planned or unplanned electrical outages. The current equipment at 1041 facility is over 20 years old and are beyond their expected useful life cycle. The existing generator is currently out of commission and does not meet current EPA and AQMD emissions standards. The scope for this project is to design replacement generator and manual transfer switch that are properly sized to support the loads of the building, which include three 125 HP pumping motors along with building and ancillary loads.

This basis of design report will describe where certain assumptions have been made, so that if additional information becomes available, the data can be re-incorporated to achieve the most accurate results possible. The salient features of the assessment of the existing conditions are to the type of electrical equipment, the age of each major system components, the current health of that component, and recommendations for replacement of the existing generators and associated electrical equipment.

ELECTRICAL DESIGN OBJECTIVE

The overall project includes the following scope:

1. Removal of existing generators and transfer switchgear

2. Installation of one new 450kW/562kVA diesel backup generators on new concrete pad

3. Installation of one new manual transfer switchgear

3.0

4.0

SITE VERIFICATION

Faculty from Design West Engineering completed a survey of the existing generator and building electrical system, and collected equipment information on the existing system based on visible name plate information and visual inspections.

The collected information will be incorporated into the 100% design. As-builts could not be obtained for the existing systems.

ASSESSMENT OF EXISTING CONDITIONS

Currently, B1041 consist of a 1200A 480V 3ph 4w electrical service each. An existing 300kW generator is connected through a manual transfer switchboard with kurt-key interlocked circuit breakers at each location. The switchboard feeds a 1200A MCC which feeds the primary POL pumps and contains separate breakers that feed ancillary loads to support the building and generator circuits.

The generators are currently and disconnected from the system and appear to be in poor condition. The manual transfer switchgear appears to be in adequate condition, however, due to the age of the equipment, they will be replaced. The existing conduits from the generator to the building switchgear will be reused where feasible while new conductors will be installed in the existing conduits.

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5.0

6.0

DEMOLITION

The existing decommissioned generator will be demolished along with the existing above ground fuel tank at B1041. The existing main service/manual transfer switchgear within the buildings that are being replaced will be demolished. All obsolete electrical distribution system equipment/components will be indicated to be removed, and not abandoned in place. Obsolete conductors will be indicated to be removed back to source.

Conduits will be indicated to be cut and capped for future use where appropriate.

The Government indicated downtime of the electrical service for replacement of the service switchgear is acceptable but must be scheduled in advance. The design will specify a minimum of 14-day notice be provided for any scheduled outages.

NEW POWER DISTRIBUTION COMPONENTS

Generators: A new backup generator set will be designed to support all critical loads.

The generator is classified as POL (petroleum, oil, & lubricants) /Fuels. The role of the generator is to provide backup power when commercial power is turned off or fails.

Based on initial sizing calculations, in order to support a minimum of 50% load required by Air Force Instruction (AFI) 32-1062, 2.3.1.4, along with motor starting inrush current, the new generators will be sized to 450kW/562kVA with 480V 3ph 4w output and a 800A 100% rated adjustable trip output circuit breaker. The generators will be housed in a level 2 sound attenuated enclosure to mitigate sound concerns and will not exceed 72 dB at 23’ away from the generator. The generators will be designed with a load bank and portable generator connections at both locations. Fuel supply will be 24 hours minimum at full rated load and shall be belly tank type, not external fuel tank. Generator fuel calculations have been provided on plans and indicate that a 1000 gal. tank will provide required run-time. The new generators will conform to all codes referenced in SOW and all applicable building codes along with EPA and AQMD emissions requirements.

The generator will be located away from the buildings on a new concrete foundation. All generator exhaust will be directed away from adjacent building openings and will be a minimum of 10’ away from any building openings. The generator enclosure will be completely enclosed.

Manual Transfer Switchgear: A new 1200A 480V 3ph 4W switchboard will be provided and connected to new generators and existing utility feed to provide manual transfer between utility and generator. Switchboard will be provided with copper bus, draw-out type thermal-magnetic molded circuit breakers with adjustable trip settings (LSIG) . A manual interlock transfer system will be provided for switching between utility and generator power as required by ETL 13.3.4.

Triple Switch: A new interconnection switch will be provided at each location to allow for load bank testing and portable generator connections as required by Air Force Instruction (AFI) 32-1062, 6.5. The switch consists of three interlocked breakers to isolate the permanent standby generator circuit from the service during load bank testing. The switch also provides a means to quickly connect a portable backup generator to the service while the permanent generator is offline.

Grounding and Surge Protection: A new grounding connection will be provided for the new separately derived systems at the generators which will be specified to be directly connected to the existing ground electrode system at the buildings.

Remote Annunciator: A remote annunciator panel will be provided inside the building at each location to provide generator status and alarms.

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7.0 SYSTEM STUDIES AND REPORTS

Fault current analysis, protective device coordination studies, and arc flash analysis studies will be specified to be performed by the installing contractor. Arc flash labels will be installed by the equipment installer for all new electrical components in accordance with study. The specifications will require the installer to perform the study based on the actual equipment being installed. Operational risks/issues identified in the study that require mitigation will be incorporated into the design. All databases for the electrical system studies will be provided to the government in softcopy.

Equipment Cut Sheets - 3