BPU PD - 14 Aug 08.doc

PD05WRLEEG11

CAGE 98752

14 Aug 2008

PURCHASE DESCRIPTION (PD)

BASIC EXPEDITIONARY AIRFIELD RESOURCES (BEAR) POWER UNIT (BPU)

1. SCOPE

1.1 Scope. This specification defines the requirements for a Basic Expeditionary Airfield Resources (BEAR) Power Unit herein referred to as BPU. The BPU is a trailer mounted, EPA compliant diesel engine-driven generator set which will be used as a prime power unit to provide electrical power in support of BEAR forward operating military bases.

1.2. Classification. The BPU shall be classified as 800 kilowatts (kW), Prime Power (Type II), Utility (Class 2A), Mode I (50/60 Hz) as defined in MIL-STD-1332B.

1.3. BPU rating. The BPU shall be rated at 800 kW at 60 Hz prime power output at 0.75 power factor (PF) lagging at up to 122° F ambient temperature and up to 4,000 feet above sea level in altitude. The BPU shall meet all defined ambient temperature and altitude requirements while using JP-8 fuel and shall be re-connectable for the following line‑to‑line voltage ratings:

a. For 60 Hz operation: 2400/4160 Volts, 3 Phase, 4 wire.

b. For 50 Hz operation: 2200/3800 Volts, 3 Phase, 4 wire.

2. APPLICABLE DOCUMENTS

2.1 General. The documents listed in this section are specified in sections 3, 4, or 5 of this specification. This section does not include documents cited in other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirements of documents cited in sections 3, 4, or 5 of this specification, whether or not they are listed.

2.2 Government documents.

2.2.1 Specifications, standards, and handbooks. The following specifications, standards, and handbooks of the exact revision listed below form a part of this specification to the extent specified herein.

FEDERAL STANDARDS

FED-STD-595B

Colors Used in Government Procurement

COMMERCIAL ITEM DESCRIPTIONS

A-A-393A Extinguisher, Fire, Dry Chemical (Hand Portable)

A-A-52464B Coupler, Drawbar, Ring: Light Duty, 60,000 lb GVW; Offset (Taper Shank), 60,000 lb GVW; and Heavy Duty, 120,000 lb GVW

MILITARY SPECIFICATIONS

MIL-DTL-5541F Chemical Conversion Coatings on Aluminum and

Aluminum Alloys

MIL-DTL-0053030B Primer Coating, Epoxy, Water Reducible, Lead and

Chromate Free

MIL-PRF-23377J(2)

Primer Coatings: Epoxy, High-Solids

MIL-PRF-26915D Primer Coating, for Steel Surfaces

MIL-PRF-62048C

Air Cleaners, Automotive: Heavy Duty, Dry-Type (For Internal Combustion Engines).

MIL-PRF-85285D(1)

Coating: Polyurethane, Aircraft and Support Equipment

MILITARY STANDARDS

MIL-STD-130N

Identification Marking of U.S. Military Property

MIL-STD-209K

Lifting and Tiedown Provisions

MIL-STD-461F

Requirements for the Control of Electromagnetic Interference Characteristics of Subsystems and Equipment MIL-STD-705C Generator Sets, Engine Driven Methods of Tests and Instructions

MIL-STD-810F Environmental Engineering Considerations and Laboratory Tests

MIL-STD-882D

Standard Practice for System Safety

MIL-STD-889B(3)

Dissimilar Metals

MIL-STD-1332B

Definitions of Tactical, Prime, Precise, and Utility Terminologies for Classification of the DOD Mobile Electric Power Engine Generator Set Family

MIL-STD-1472F(1)

Human Engineering

DEPARTMENT OF DEFENSE HANDBOOKS

MIL-HDBK-781A

Handbook for Reliability Test Methods, Plans, and Environments for Engineering, Development, Qualification, and Production

MIL-HDBK-1791

Designing for Internal Aerial Delivery in Fixed Wing Aircraft

MIL-HDBK-1791

C-17 Appendix Designing for Internal Aerial Delivery in Fixed Wing Aircraft C-17 Appendix

(Copies of these documents, except for copy of MIL-HDBK-1791 C-17 Appendix, are available online at http://assist.daps.dla.mil/quicksearch/ or www.dodssp.daps.mil or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094. A copy of MIL-HDBK-1791 C-17 Appendix can be obtained from the Procuring Contracting Officer (PCO) or requested by contacting Air Transportability Test Loading Agency (ATTLA) at 937-255-6296.)

2.2.2 Other Government documents, drawings, and publications. The following other Government documents, drawings, and publications form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract.

US Army Tank Automotive Command AMSTA-IM-MM

11682345

Vehicle Receptacle Assembly NATO Intervehicle Power, 24 VDC (Application for additional information should be addressed to US Army Tank Automotive Command AMSTA-IM-MM, 11 Mile Rd, Warren MI 48397.)

2.3 Non-Government publications. The following documents form a part of this document to the extent specified herein. Unless otherwise specified, the issues of the documents which are DoD adopted are those listed in the issue of the DoDISS cited in the solicitation. Unless otherwise specified, the issues of documents not listed in the DoDISS are the issues of the documents cited in the solicitation or contract.

Cooper Power Systems Inc

LE215A06X

Load Elbow Connector, 200A, 15 kV

(Applications for additional information should be addressed to Cooper Power Systems Inc, 2300 Badger Dr, Waukesha WI 53188-5951.)

DRS TSI

1R0396 Fuel Manifold Assembly - Hose Assembly, Manifold to Generator

(Applications for additional information should be addressed to DRS TSI, 12930 Worldgate Drive Ste 700, Herndon VA 20170.)

International Organization for Standardization (ISO) 5011 Inlet Air Cleaning Equipment for Internal Combustion Engines and

Compressors – Performance Testing

8528-1 Reciprocating Internal Combustion Engine Driven Alternating Current Generating Sets

(Applications for copies should be addressed to ISO Copyright Office, Case postale 56, CH-1211 Geneva 20, Switzerland, www.iso.org.)

National Electrical Manufacturers Association (NEMA)

MG‑1

Motors and Generators

MG-2

Safety Standard for Construction and Guide for Selection, Installation and Use of Electric Motors

(Applications for copies should be addressed to NEMA, 1300 North 17th Street, Suite 1847, Rosslyn, VA, 22209, www.nema.org.)

National Fire Protection Association (NFPA)

National Electrical Code, 2005

(Application for copies should be addressed to NFPA, Batterymarch Park, Quincy MA 02169-7471, www.nfpa.org.)

Pirelli Power Cables and Systems North America

Q5Q030A

High Voltage Aluminum Cable, 1/0 AWG, 5 kV

(Applications for additional information should be addressed to Pirelli Power Cables and Systems North America, United States: 246 Stoneridge Drive, Columbia, SC 29210, www.na.pirelli.com.)

Society of Automotive Engineers (SAE)

ARP1247C

General Requirements for Aerospace Ground Support Equipment, Motorized and Nonmotorized

AS35061

Connector, Receptacle External Electric Power, Aircraft, 28 Volt DC Operating Power

AS8090

Equipment, Towed Aerospace Ground, Mobility J1349 Engine Power Test Code—Spark Ignition and Compression Ignition—Net Power Rating (Application for copies should be addressed to SAE, Inc., 400 Commonwealth Drive, Warrendale PA 15096.)

The Tire and Rim Association

2008 Year Book

(Application for copies should be addressed to The Tire and Rim Association, Inc., 175 Montrose West Ave., Suite 150, Copley OH 44321.)

2.4 Order of precedence. In the event of a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained.

3. REQUIREMENTS

3.1 Preproduction samples. When specified (see 6.2), eight samples shall be subjected to preproduction inspection in accordance with 4.2.

3.2 BPU description. The BPU shall be a fully enclosed, trailer mounted, mobile generator set. The BPU shall consist of a single diesel engine directly connected through a coupling to a single brushless alternating current (AC) generator and all necessary subassemblies and components to meet the requirements of this specification.

3.2.1 BPU output power. The BPU shall provide the power output characteristics listed below.

3.2.1.1 Output power rating. The BPU shall be capable of delivering at least 800 kW prime output power, 2400/4160 VAC, 60 Hz, 3 phase, at 0.75 power factor lagging, in an ambient temperature not less than 122° F and at 4,000 feet altitude while using JP-8 fuel. The BPU shall also be able to deliver prime power output for 50 Hz loads at the power output rating specified by the manufacturer and shall be re-connectable for the following line‑to‑line voltage ratings:

a. For 60 Hz operation: 2400/4160 Volts, 3 Phase, 4 wire.

b. For 50 Hz operation: 2200/3800 Volts, 3 Phase, 4 wire.

3.2.2 Continuous operation. The BPU shall be designed to provide prime power output of 800 kW at 60 Hz, with a 0.75 power factor lagging and prime power output rating (kW) specified by the manufacturer at 50 Hz, with a 0.75 lagging power factor for continuous operation with varying loads and as defined in 13.3.2 of ISO 8528-1:1993, First Edition.

3.2.3 Overload capability. The BPU shall be capable to provide 10% overload power in an ambient temperature not less than 122° F and at 4,000 feet altitude while using JP-8 fuel: at least 880 kW at 60 Hz and 10% overload power of power output rating (kW) specified by the manufacturer at 50 Hz for 1 hour within a 12-hour period of operation.

3.2.4 Steady state output voltage and frequency. The BPU output voltage shall be three (3) phase, four (4) wire configuration and 2400/4160 VAC at 60 Hz and 2200/3800 VAC at 50 Hz at the BPU output terminals. The output voltage shall be adjustable to ± 10 percent from nominal, but shall have a steady state regulation of ± 1 percent at all settings from no load to full load. The output frequency shall be adjustable to ± 4 percent from nominal, but shall have a steady state regulation of ± 0.25 percent at all settings from no load to full load.

3.3 Design and construction. The BPU shall be constructed so that parts do not work loose in service and shall withstand the loads, shocks, vibrations, and other conditions incident to operation, shipping, and storage without permanent distortion and with minimum loss of time for maintenance, repair, and servicing. The BPU design shall ensure safe, efficient, and economical operation. All assemblies, controls, and installed equipment shall be located so that there is no adverse interference with each other, or with the operation, and shall be readily accessible for maintenance, operation, removal, and replacement. All cable connectors shall be secured, covered, and weather protected when not in use.

3.3.1 Fire prevention, system safety, design, and construction practices. The BPU shall be designed to minimize the risk of fire. It shall be equipped with a fire extinguisher in accordance with A-A-393A, Type I, Class 1, and Size 5, mounted on the exterior of the enclosure. The BPU design shall not contain any system safety mishap risk categories greater than medium as defined in Table A-IV of MIL-STD-882D. The design and construction of the electrical portions of the BPU shall be in accordance with NFPA 70. The BPU shall have a solidly grounded neutral and the electrical grounding of the BPU shall be accomplished in accordance with Article 250 of NFPA 70. Two grounding points shall be provided. One grounding point shall be located externally for the grounding electrode. A second grounding point shall be located in the immediate vicinity of the load break elbow connections. All parts (grounding rods, clamps, ground cable, etc.) for grounding assembly shall be provided and stored within the BPU enclosure.

3.3.2 Environmental conditions.

3.3.2.1 Operating temperature range. The BPU shall be capable of operating in ambient temperatures ranging from -25o F to +122o F (Threshold), from -25o F to +140o F (Objective) without de-rating.

3.3.2.2 Storage temperature range. The BPU shall be capable of being stored in ambient temperatures ranging from -65o F to +160o F.

3.3.2.3 Altitude. The BPU shall be capable of operating at any altitude from sea level to 4,000 feet without de-rating. De-rating of the BPU shall be allowed at altitudes above 4,000 feet. The BPU shall be capable of storage and transportation at any altitude from sea level to 40,000 feet.

3.3.2.4 Rain. The BPU shall be capable of storage and operation during rainfall of 5-inches per hour for three consecutive hours and 10-inches per hour for 10 consecutive minutes, with winds of up to 35 knots; and with 6-inches of rain per hour impinging on the BPU at angles from vertical to 45°.

3.3.2.5 Solar radiation. The BPU shall not be adversely affected by full time exposure to solar radiation, such as those conditions encountered in desert environments.

3.3.2.6 Fungus. All materials used in the BPU shall be fungus resistant or shall be suitably treated to resist fungus. Materials treated for fungus resistance shall retain their original electronic and physical properties, shall not present toxic hazards, and treatment shall last for the entire service life of the part. The BPU shall be suitable for operation and storage in conditions encountered in a tropical environment.

3.3.2.7 Salt fog. The BPU shall be capable of storage and operation in high temperature, high humidity, salt laden, sea coast environments without damage or deterioration of performance.

3.3.2.8 Sand and dust. The BPU shall be capable of storage and operation during exposure to 1400 milligrams per cubic meter wind-blown sand (particle size 150-1000 microns) for 90 minutes or dust (particle size 10-150 microns) at wind speeds up to 60 miles per hour (mph) for 12 hours without damage or deterioration of performance.

3.3.2.9 Snow and ice. The BPU shall be capable of storage and operation during snow accretion up to 2-inches per hour for at least 12 hours and up to 37 mm of ice.

3.3.3 Weight and dimensions. Overall weight in air transport configuration and dimensions shall not exceed:

Weight

- 40,000 pounds.

Length - 432 inches.

Width - 96 inches.

Height - 116 inches.

The BPU air transport configuration is full of coolant and lubricating oil, but with the fuel tank drained. The center of gravity of the BPU shall be stenciled on the unit within 1.0 inch of the calculated center of gravity.

3.3.4 Materials, protective coatings, and finish.

3.3.4.1 Protective coatings. Materials that deteriorate when exposed to sunlight, all environmental conditions specified herein, or operational conditions normally encountered during the service life of the BPU shall not be used or shall have means of protection against such deterioration that does not prevent compliance with the performance requirements specified herein. Protective coatings that chip, crack, or scale with age or extremes of climatic conditions or when exposed to heat shall not be used. Fasteners, handles, and fittings used in the assembly of the BPU shall also be primed and painted. Surface preparation and pretreatment shall be in accordance with the respective primer and topcoat specifications. Structures shall be cleaned and degreased and scuffed or blasted prior to priming; primer shall be applied before any oxidation or rusting occurs. Ferrous structures and surfaces shall be primed with a water reducible zinc rich primer in accordance with MIL-PRF-26915D Notice 2, Type II, Class B; this shall be followed, within four hours, by a coat of MIL-DTL-0053030B intermediate primer in a wet-to-wet primer application. This two part primer system shall yield a dry-film thickness of 2.0-2.5 mils for the zinc rich primer and 0.9-1.1 mils for the intermediate primer. After the two primer system is applied, the surface shall be allowed to fully cure, per the manufacturers directions, prior to topcoating. Aluminum surfaces shall have MIL-DTL-5541F, Type I, Class 1A, chromate conversion coating applied per the manufactures direction prior to priming. Aluminum and mixed aluminum and ferrous structures and surfaces shall be primed with strontium chromate based corrosion inhibitor, Type I, Class C2 of MIL-PRF-23377J(2). This single part primer system shall yield a dry-film thickness of 0.6-0.8 mils. Raw metal edges, to include fastener and drain holes, shall be coated with the primer before applying topcoat. Topcoat shall be polyurethane in accordance with Type I, Class H of MIL-PRF-85285D(1). Neither Chemical Agent Resistant Coating (CARC) nor powder coating shall be used. Topcoat shall be applied to a dry-film thickness of 1.6-2.4 mils in all instances, regardless of the primer system utilized. The topcoating shall be free from runs, sags, orange peel, or other defects.

3.3.4.2 Dissimilar metals. Dissimilar metals, as defined in MIL-STD-889B(3) Notice 2, shall not be in contact with each other. Metal plating or metal spraying of dissimilar base metals to provide electromotively compatible abutting surfaces is acceptable. The use of dissimilar metals only when separated by suitable insulating material is permitted, except in systems where bridging of insulation materials by an electrically conductive fluid can occur. Sealants or gel type gasket materials shall be used between faying surfaces and butt joints.

3.3.4.3 Finish. The exterior finish color shall be Sand Matte, Color Number 33446 of FED-STD-595B.

3.3.4.4 Sound suppression material. Sound absorbing/suppression material shall be of the non-moisture absorbing type, so that condensation and rain water are not absorbed and held adjacent to metal structure and panels. Fiberglass, felt, and open cell foam shall not be used for sound suppression.

3.3.4.5 Fluid traps and faying surfaces. There shall be no fluid traps on the BPU. Faying surfaces of all structural joints, except welded joints, shall be sealed to preclude fluid intrusion.

3.3.5 Markings. All external devices (i.e., ground terminal, paralleling receptacle, caution plate, lifting, tie down, forklift opening, center of gravity, etc) which require an operational or maintenance interface shall be marked in accordance with MIL-STD-130N. Painted markings shall be one inch high block letters unless prohibited by the available space. In such cases, the markings shall be the largest size possible, but shall not be less than one-half inch high. Markings, Information/Caution shall be Lusterless Black, Color Number 37038 of FED-STD-595B, and Markings, Warning/Danger shall be Lusterless Red, Color Number 31136 of FED-STD-595B.

3.3.5.1 Identification plate. An identification plate in accordance with MIL-STD-130N shall be securely attached to the BPU in a readily accessible location. The identification plate shall contain the following information: nomenclature, part number, kW, Hz, voltage, power factor, phase ratings, serial number, date of manufacture, manufacturer’s name, Commercial and Government Entity (CAGE) code, date of warranty expiration, and National Stock Number (NSN). The BPU and any BPU components meeting Unique Identification (UID) criteria shall have UID information in accordance with MIL-STD-130N permanently affixed near the respective identification plate(s).

3.3.5.2 Start-up/shut-down instructions. Step-by-step operating instructions for start-up/shut-down of the BPU shall be imprinted on the unit and easily visible while operating controls on the control panel.

3.3.5.3 AC/DC schematic wiring diagrams. The BPU AC and DC schematic wiring diagrams shall be securely attached to the inside panel doors.

3.3.6 Human engineering. The BPU shall be designed in accordance with MIL-STD-1472F (1) for ease of operation, inspection, and maintenance, including the use of arctic mittens and Mission-Oriented Protective Posture (MOPP) Level 4 Chemical Warfare Gear.

3.3.7 Sound levels. The BPU, at any load from no load to rated load, shall have a maximum sound level of 84 dBA at 7 meters from the perimeter of the BPU when measured at 1.75 meters above the ground.

3.3.8 Vibration. The vibration of the engine shall not exceed 5 mils and a maximum velocity of 0.70 inches per second in the horizontal, vertical, and transverse planes. The vibration of all components in the BPU except the engine shall not exceed 6 mils and a maximum velocity of 0.70 inches per second in the horizontal, vertical, and transverse planes. Vibration shall not cause damage such as loosening of parts, breakage of fasteners, breaking of electrical or hydraulic connections, or anything else that will impair the function of the BPU.

3.3.8.1 Torsional vibration. The BPU engine idle speed and continuous operating speeds for both 60 Hz and 50 Hz power generation shall not be within the range of 60 percent to 150 percent of any engine-generator torsional resonance speed.

3.3.9 Electromagnetic interference. The BPU shall be in accordance with the following radiated emission and susceptibility requirements of MIL-STD-461F: RE102 and RS103.

3.3.10 Electrostatic discharge. The design of the BPU shall preclude equipment damage due to electrostatic discharge (ESD), protect personnel from electrical shock due to static charging, and prevent ignition of explosive atmospheres due to sparking.

3.3.11 Component protection. All space in which work is performed during operation, service, and maintenance shall be free of hazardous protrusions, sharp edges, or other features which may cause injury to personnel. All rotating and reciprocating parts and all parts subject to high operational temperatures or subject to being electrically energized, that are of such nature or so located as to be hazardous to personnel, shall be guarded or insulated to eliminate the hazard.

3.3.12 Foolproofness. Where improper installation of an item causes a malfunction, an asymmetric mounting system shall be provided, where practical, to ensure proper mounting of the item.

3.3.13 Fastening devices. All screws, bolts, nuts, pins, and other fastening devices shall be properly designed, manufactured, and installed with adequate means of preventing loss of torque or adjustment. Cotter pins, lock washers, or nylon patches shall not be used for this purpose, except for the attachment of trim items or as provided in commercial components. Tapped aluminum threads shall have a minimum thread engagement of at least two times the nominal fastener diameter.

3.3.14 Foreign object damage. All loose metal parts, such as pins or connector covers, shall be securely attached to the BPU with wire ropes or chains. "Dog tag" style beaded chains shall not be provided. Removable panels, if provided, shall be attached with captive fasteners. Tire valve stem caps shall be made of plastic.

3.3.15 Hydraulic system design. If a hydraulic system is utilized, it shall be in accordance with 3.13.1.3 of SAE ARP1247C except as otherwise specified herein. O-ring face seal hydraulic fittings may be used in lieu of flared fittings (see 3.13.1.3.12 of SAE ARP1247C). All hydraulic system components, including the hydraulic tank, shall comply with all corrosion resistance requirements specified herein.

3.4 Engine and related equipment. The engine and related equipment shall be in accordance with Appendix A except as otherwise specified herein. The net power output rating of the engine, when operated on JP-8 fuel at 4,000 feet elevation at +122o F (Threshold), at +140o F (Objective) high ambient temperature and determined in accordance with SAE J1349, shall be adequate for all performance requirements specified herein.

3.4.1 Engine exhaust emissions. The engine shall be a diesel that is certified to comply with the Tier II Environmental Protection Agency (EPA) off-highway emission requirements.

3.4.2 Engine starting. The engine shall start within 15 seconds in any ambient temperature within the required operating range of the BPU. Installed fluid starting aids and heat from the winterization system may be used prior to and during the start period to facilitate engine starting under the following conditions:

Temperature Range

Starting Aids Permitted

A winterization system may be provided for starting in temperatures down to -25° F. The winterization system may include heaters for engine coolant, engine oil, and the fuel tank, as well as battery warmers. The winterization system shall be designed to operate from an external 28-volt DC power source utilizing the external DC connections (see 3.10.3). The winterization system shall incorporate high-temperature shutoff switches to prevent overheating of any fluid or component.

3.4.3 Engine cooling system. The BPU engine cooling system shall be in accordance with A.3.3.3 and shall also be designed to allow the BPU to operate safely and reliably in any ambient temperature specified herein at rated power output level. The engine cooling system shall neither draw nor exhaust air beneath the BPU, nor shall the cooling system air intake be located near the engine exhaust system outlet. The cooling system shall be electrically driven and shall be rated for continuous operation.

3.4.4 Engine air intake system. The engine air intake system shall be in accordance with A.3.3.4 and shall include a centrifugal type pre-filter, a primary replaceable dry element, and a secondary dry element. The air filtration system shall be capable of operation without service for 20 hours while exposed to fine grade air cleaner dust in accordance with ISO 5011 at 2 grams per cubic meter. Replacement of the primary element shall be accomplished in less than five minutes without the use of special tools or removal of the secondary element. The inlet shall not draw air from beneath the BPU and shall not be located near the cooling system air outlet nor the engine exhaust outlet. Joints shall be minimized between the air filter outlet and the actual engine air inlet and shall be designed to ensure no leakage of unfiltered air into the engine. A differential pressure air filter service indicator shall be provided.

3.4.5 Engine lubrication system. The BPU engine lubrication system shall be in accordance with A.3.3.5 and shall be designed so that the BPU can be operated on a ± 8 degrees slope in any direction.

3.4.6 Fuels. The BPU engine shall start and operate satisfactorily on all of the fuels listed with no additional additives required: JP-8 as primary and JP-5, DF-1, DF-2, TS-1 with JP-8 additives, DL-1, DL-2, Jet A, Jet A1, LS1, LS2, DS1, and DS2 as secondary. See A.3.3.6.1 and A.3.3.6.2 for further information on the required fuels.

3.4.6.1 Fuel system. The BPU fuel system shall be in accordance with A.3.3.6.4, A.3.3.6.5, and A.3.3.6.6. The engine fuel consumption shall be in accordance with A.3.3.6.3.

3.4.6.1.1 Fuel tank. The BPU shall be equipped with a fuel tank (day tank) sized to contain sufficient fuel to provide at least one hour of usable fuel for continuous operation at full load. The tank shall be in accordance with A.3.3.6.7. The tank shall be provided with corrosion protection and baffles. The tank shall be designed so that the BPU can be operated on a ± 8 degrees slope in any direction. A drain valve shall be provided for emptying fuel and sediment into a container outside the BPU without removal of the tank or any other major component.

3.4.6.1.2 External fuel feed. An external fuel system shall be provided. It shall include a 2-position fuel selector switch, to allow operator selection of fuel feed from the onboard fuel tank (OFF) or from an external fuel source (ON). The switch shall be labeled “External fuel ON/OFF”. The external fuel system shall include an electric fuel transfer pump, electric valve, fuel level sensor, plumbing, and external fittings; quick disconnect type fittings shall be supplied. The unit shall be capable of drawing fuel from external storage sources, fuel bladders, tanks, fuel trucks, etc, located on the same horizontal level as the base of the BPU and no more than 100 feet away. See 3.10.2 for the external fuel interface.

3.4.7 Exhaust system. The exhaust system shall include a muffler, necessary pipes, and fittings to discharge the exhaust gases to the outside of the BPU. The exhaust system shall be in accordance with A.3.3.7. Exhaust system outlet(s) shall be directed upward, away from personnel accessing the control panel or any enclosure doors, the towbar, the engine air intake and the cooling system air intake, and shall not be directed toward the ground. The design of the exhaust system outlet(s) shall preclude the entry of rain. If the exhaust system doesn’t fit within the shipping dimensional envelope, the reconfiguration in accordance with 3.12.2.1 shall be required prior to shipment.

3.4.8 Governing system. The governing system shall govern the BPU and maintain the specified performance modes at all environmental conditions and on the fuels specified herein. The governing system shall be capable of controlling the BPU load either independently, in parallel with other BPUs, or with the commercial power grid. At the specified environmental, temperature, and altitude conditions specified herein, the governing system shall maintain the engine speed within the frequency limits.

3.4.8.1 Frequency regulation. The governor shall have an adjustable speed droop from 0 to 3 percent of rated frequency. The frequency regulation of zero droop (isochronous mode) shall not exceed ± 0.25 percent (steady state) of frequency setting from no load to full load. The governing system shall also automatically monitor and regulate the output frequency within the limits specified herein.

3.4.8.2 Short-term frequency stability (30 sec). At every constant load from no load to rated load, the speed governing system shall maintain frequency within a bandwidth equal to 0.5 percent of rated frequency. The governing system shall not permit repetitive periodic frequency variation, commonly called hunting, even if within the allowable 0.5 percent band.

3.4.8.3 Frequency drift. With the BPU operating at constant load and voltage, a change in the ambient temperature of 60° F in an 8‑hour period shall not cause the frequency to change by more than 0.5 percent.

3.4.8.4 Frequency transient performance. With a sudden 50 percent change in load between no load and rated load, the speed governing system shall re‑establish stable engine operating conditions within 4 seconds. The maximum transient frequency change above the new steady state frequency (overshoot) shall be not more than 4 percent of rated frequency. The maximum transient frequency change below the new steady state frequency (undershoot) shall be not more than 4 percent of rated frequency. In addition, the circuit breaker shall not trip when the load is suddenly increased and decreased from no load to rated full load and from rated full load to no load in one step.

3.4.8.5 Frequency adjustment. The BPU shall provide ± 4 percent range of rated frequency adjustment for use in parallel operations. Both manual and automatic adjustment capability shall be provided.

3.4.9 Engine protective circuits. The engine protective circuits, when activated, shall shut down the engine operation and activate the fault indication system.

3.4.9.1 Over temperature engine protection circuits.

3.4.9.1.1 Engine coolant temperature. This over temperature protection circuit shall shut down the engine operation when engine coolant temperature exceeds the maximum value defined by the engine manufacturer.

3.4.9.1.2 Engine oil temperature. This over temperature protection circuit shall shut down the engine operation when engine oil temperature exceeds the maximum value defined by the engine manufacturer.

3.4.9.2 Overspeed engine protection circuit. The over speed engine protection circuit shall shut down the engine operation when engine operating speed exceeds the speed defined by the engine manufacturer by 10 percent or at the engine manufacturer’s recommended safety shut down speed.

3.4.9.3 Low oil pressure engine protection circuit. The low oil pressure protection shall shut down the engine when engine oil pressure falls below the allowable oil pressure specified by the engine manufacturer.

3.4.9.4 Low fuel level engine protection circuit. When operating from the internal fuel tank, the low fuel level engine protection circuit shall shut down the engine prior to the fuel tank being emptied so as to prevent the engine fuel system from loosing its prime.

3.4.9.5 Built-in-protection (BIP). The BIP circuitry shall continuously monitor the generator performance, engine function, and protective circuits operation. When a malfunction is detected, the BIP shall inhibit the BPU from operation and activate the fault indication system. The BIP shall perform a complete system self-test prior to start-up through the “Power On” switch. An illuminated “Power On” indicator shall indicate all systems are functional and battery power is available to the engine and control circuits. The BIP shall detect all malfunctions that caused the BPU to fail to operate under its normal conditions.

3.5 Generator. The generator shall be continuous duty alternating current (AC). The generator kW output power rating shall be adequate to meet kW output power rating requirements of the BPU under all conditions specified herein. The generator shall be of the rotating field, brushless, synchronous type and shall be either the single or double bearing type. The generator windings shall be Class H insulation. The generator shall be of the drip-proof, guarded machine type specified, designed, constructed, and installed in accordance with NEMA MG-1 and MG-2, and shall be adequate to meet all performance requirements specified herein.

3.5.1 Winding insulation resistance. The insulation resistance shall not be less than 100 meg‑ohms at 77° F, 40 percent relative humidity when measured between winding and ground.

3.5.2 Generator performance. The generator, together with the excitation system, shall provide for operation at the overload capability of the engine and meet all performance requirements as specified herein. The generator shall have an inherent limit of 150 percent of rated voltage for any condition of load and field at rated frequency and any ambient condition specified herein.

3.5.3 Voltage waveform.

3.5.3.1 Deviation factor. The deviation factor for the line-to-line and line-to-neutral voltage waveform for each voltage test point shall be less than 5 percent.

3.5.3.2 Harmonic content. From no load to full load, the Root Mean Square (RMS) value of the sum of all the harmonic components in the output voltage waveform line-to-line, and also line-to-neutral, shall not exceed 5 percent of the RMS value of the rated voltage. The RMS value of any single component shall not exceed 3 percent of the RMS value of the rated output voltage under the above condition. In addition, there shall be no spikes or notches in the waveform.

3.5.4 Voltage phase balance. The maximum difference between the output voltages of any phase from no load to full load shall not exceed 1 percent of rated line-to-neutral voltage.

3.5.4.1 Voltage unbalance. With the generator under control of the excitation systems, and operating with rated voltage and frequency, the maximum difference between line-to-line voltages shall be no more than 5 percent of rated voltage under the condition of a single phase, unity power factor load of 25 percent of rated current connected line-to-line, with no other load on the set.

3.5.5 Voltage transient performance.

a. With the BPU initially operating at rated frequency and rated voltage, and following any sudden change in load from no load to half load, the instantaneous voltage shall not drop to less than 80 percent of rated voltage and shall reach stable conditions within 3 seconds. No overshoot or undershoot of the final voltage may exceed the initial voltage transient in amplitude.

b. The above requirements shall also apply when load is suddenly changed from half load to no load, except that the initial voltage transient shall involve a voltage rise not to exceed 130 percent of rated voltage.

c. With the BPU initially operating at no load, rated voltage, and rated frequency, the instantaneous voltage shall not drop to less than 60 percent of the no load rated voltage when a balanced 3‑phase, 0.4 power factor or less, lagging static load having an impedance of 0.5 per unit is applied to the output terminals of the BPU. The generator shall recover to not less than 95 percent of rated voltage within 5 seconds and shall stabilize at or above this voltage.

3.5.6 Voltage modulation. The voltage modulation for each of the line-to-line and line-to-neutral voltages for any load up to and including the rated load shall not exceed 1 percent of the peak-to-peak voltage.

3.5.7 Voltage regulation and adjustment.

3.5.7.1 Voltage regulation. At any load, from no load to rated load (steady state), the output voltage of the BPU shall be maintained within ± 1 percent of output voltage setting.

3.5.7.2 Voltage adjustment. At any load, from no load to rated load (steady state), the output voltage of the BPU shall be manually adjustable (± 10 percent) to any value within the line-to-neutral and line-to-line voltage operating range of:

a. 2160V to 2640V/3744V to 4576V at 60 Hz.

b. 1980V to 2420V/3420V to 4180V at 50 Hz.

3.5.8 Output phase sequence. The phase sequence of output voltage shall be positive sequence of A-B-C (AB-BC-CA).

3.5.9 Short circuit. The generator, exciter, and voltage regulator operating as a unit shall withstand the following short circuits at the BPU output terminals, when operating at rated load, without any electrical or mechanical damage and degradation:

a. A 6‑second asymmetrical (line-to-neutral and line-to-line) short circuit with a sustained short circuit current of not less than 400 percent of rated output current.

b. A 10‑second symmetrical three‑phase short circuit with a sustained short circuit current of not less than 300 percent of rated current.

3.5.10 Generator protective devices. Activation of a protective device shall trip the generator circuit breaker and provide an indication of trip action which includes but is not limited to both an audible and visual alarm that indicates there is a problem with the unit. All protective devices shall have manually reset trip indicators.

3.5.10.1 Overcurrent. The overcurrent protective device shall operate when the load current on all three phases exceeds 110 percent of the rated current of the BPU. The device shall trip at the value recommended by the manufacturer.

3.5.10.2 Synchronizing check relay (manual mode of operation). With the parallel switch in the parallel position and the synchronizing switch in the ON position, the synchronizing check relay shall verify that the generator is synchronized (proper voltage, frequency, and phase coincidence) with the bus before the circuit breaker can be closed.

3.5.10.3 Overvoltage. The BPU shall trip off line within 5 seconds of exceeding 110 percent rated output voltage.

3.5.10.4 Undervoltage. The BPU shall trip off line within 5 seconds when voltage falls below 90 percent rated output voltage.

3.5.10.5 Reverse power. The reverse power protection device shall actuate when the power flow into the BPU reaches a maximum of 20 percent of the BPU rating or more stringent as recommended by the manufacturer.

3.5.10.6 Ground fault. The ground fault relay (protection device) shall be provided and actuate at the value recommended by the manufacturer.

3.5.11 Lightning arresters and surge capacitor(s). The lightning arresters and surge capacitor(s) shall be incorporated into the BPU and shall meet all performance requirements specified herein.

3.6 Control systems. The control systems of the BPU consist of an electronic control unit governing system, voltage regulation, electrical output protective circuits, and built-in-test (BIT) circuits. The control systems shall utilize solid-state electronics to provide complete automatic control and to monitor the BPU performance including, but not limited to, the engine, generator, and output power. The control system shall permit up to no less than twelve (12) BPUs to operate in parallel. All BPUs shall share real (kW) and reactive (kVAR) loads in accordance with 3.6.1. Control circuitry shall be designed to prevent a reversed power situation while a BPU is paralleling into the electrical system. Each BPU shall have output contactor(s) or circuit breaker(s) capable of power interruption and shall disconnect or remove power from the main load bus without any damage if the respective power becomes unacceptable or under a fault condition. In a power plant configuration when multiple BPUs are paralleled, they shall be monitored and controlled by a separate computer logic device such as a PC (through a standard communications port, i.e. serial port, USB, industrial bus, or Ethernet) or a removable control panel. The remote control device shall replicate the functions of the on-board control panel.

3.6.1 Parallel operation. The BPU shall have automatic and manual paralleling capabilities integrated into the unit. The BPU shall have manual and automatic paralleling capabilities to operate in parallel with the other BPUs. The BPU shall have manual or automatic paralleling capability to be paralleled with the commercial power grid. When BPUs are operating in parallel, the difference between the BPUs that assume highest and lowest loads shall never be more than 10 percent of the kW and the kVAR ratings of the BPU. All BPUs, when operating in parallel, shall supply power to the primary switching center (PSC) that already exists in the Government inventory. Paralleling cables, if required, shall be provided with each BPU and shall be long enough to connect no less than 12 BPUs in a line parallel to each other spaced a minimum of 15 feet from each other. The paralleling cables shall hang naturally from the BPU and be capable of lying on the ground. Storage for the paralleling cables shall be provided within the BPU enclosure.

3.6.2 Control panel. All instruments and operating controls of the BPU shall be readily accessible and located together on a single panel. The BPU control panel shall have as a minimum the instruments and controls as listed below:

Ammeter. An ammeter with a selector switch to select phase currents shall be provided on the BPU control panel.

Voltmeter. A voltmeter with a selector switch to select Line-to-Line and Line-to-Neutral voltages shall be provided on the BPU control panel.

Frequency meter. A frequency meter shall be provided on the BPU control panel to indicate the output frequency of the BPU.

Power meters.

Wattmeter. A wattmeter shall be provided on the BPU control panel to indicate real kW power output of the BPU.

Reactive power meter. A reactive power meter shall be provided on the BPU control panel to indicate reactive kVAR power output of the BPU.

Power factor meter. A power factor meter shall be provided on the BPU control panel to indicate the power factor of the BPU output.

Synchronoscope. A synchronoscope meter shall be provided on the BPU control panel to be used during manual synchronizing operations.

Synchronizing lights. Lamps or light emitting diodes (LEDs) shall be provided on the BPU control panel to be used when manually paralleling to bring an incoming BPU on line in phase.

Ground fault indicator. A lamp or LED shall be provided on the BPU control panel to indicate a ground fault condition.

Reverse power indicator. A lamp or LED shall be provided on the BPU control panel to indicate a reverse power condition.

Overcurrent indicator. A lamp or LED shall be provided on the BPU control panel to indicate an overcurrent condition.

Overvoltage indicator. A lamp or LED shall be provided on the BPU control panel to indicate an overvoltage condition.

Undervoltage indicator. A lamp or LED shall be provided on the BPU control panel to indicate an undervoltage condition.

Alarm disable. A lamp or LED shall be provided on the BPU control panel to indicate the alarm silence device is in the enabled position.

Output circuit breaker/contactor on. A lamp or LED to indicate that the BPU output circuit breaker/contactor is ON shall be provided on the control panel.

Output circuit breaker/contactor off. A lamp or LED to indicate that the BPU output circuit breaker/contactor is OFF shall be provided on the control panel.

Running time meter. A running time meter (hourmeter) shall be provided on the BPU control panel to register accurate engine running time.

Lubricating oil pressure gauge. A lubricating oil pressure gauge shall be provided on the BPU control panel to indicate the pressure of the engine lubricating oil.

Low oil pressure indicator. A lamp or LED shall be provided on the BPU control panel to indicate low oil pressure of the engine.

Lubricating oil temperature gauge. A lubricating oil temperature gauge shall be provided on the BPU control panel to indicate the temperature of the engine lubricating oil.

High oil temperature indicator. A lamp or LED shall be provided on the BPU control panel to indicate high oil temperature of the engine.

Coolant temperature gauge. A coolant temperature gauge shall be provided on the BPU control panel to indicate the temperature of the coolant leaving the engine.

High coolant temperature indicator. A lamp or LED shall be provided on the BPU control panel to indicate excessive engine coolant temperature.

Exhaust temperature gauge. An exhaust temperature gauge shall be provided on the BPU control panel to indicate the temperature of the exhaust leaving the engine.

Tachometer. A tachometer shall be provided on the BPU control panel to indicate the speed of the engine.

Overspeed indicator. A lamp or LED shall be provided on the BPU control panel to indicate excessive speed of the engine.

Battery charge ammeter. A battery charge ammeter shall be provided on the PBU control panel to indicate charge/discharge rate of the batteries.

Fuel level gauge. A fuel level gauge shall be provided on the BPU control panel to indicate fuel level of the fuel tank.

Low fuel level indicator. A lamp or LED shall be provided on the BPU control panel to indicate low level of fuel in the fuel tank. The indicator shall first illuminate when the fuel level is sufficient for at least 15 minutes, but not more than 20 minutes, of operation at full power before activation of the low fuel level engine protection circuit.

Start/stop/run switch. A start/stop/run switch shall be provided on the BPU control panel to operate start, stop, and run of the engine.

Push-to-test device. A push-to-test button or switch shall be provided on the BPU control panel to test the indicating lamps, LEDs, and display panel for the BPU.

Emergency stop push-button/switches. An emergency stop push-button/switch shall be provided on the control panel and within the immediate vicinity of the engine compartment to stop the BPU. When it is activated, the output circuit breaker/contactor shall open its contact, and then the engine shall be shut down.

Output circuit breaker/contactor. An output circuit breaker/contactor shall be provided on the BPU control panel to open or close the output control device.

Parallel/single unit operation switch. A parallel/single unit operation switch shall be provided on the PBU control panel to select parallel or single unit operation.

Manual and automatic frequency adjusting controls. Manual and automatic frequency adjusting controls shall be provided on the BPU control panel to allow manual and automatic adjustment of BPU frequency within the specified frequency operating ranges.

Manual voltage adjusting control. A manual voltage adjusting control shall be provided on the BPU control panel to manually adjust the BPU output voltage within the specified voltage operating ranges.

System alarm. A lamp or LED shall be provided on the BPU control panel to indicate that fault conditions exist. This indication shall be latched in the ON position during alarm condition and shall remain ON until the alarm reset push-button is pressed.

Alarm annunciator. The BPU shall be capable of detecting and displaying as a minimum the conditions listed in this specification.

Audible alarm. An audible alarm to sound the BPU alarm condition shall be provided on the control panel.

Alarm silence. A device to silence the BPU audible alarm shall be provided on the control panel. This device shall not clear the fault or test failure indicators.

Alarm reset. The BPU shall be provided with a device to reset or clear all alarm or test failure indications. This device shall not prevent a fault from being displayed again if it is still valid.

3.6.3 Illumination. The BPU control panel shall be arranged and adequately illuminated so that all controls, switches, and displays shall be legible and may be operated in any ambient lighting condition to include bright sunlight and darkness. The control panel shall have selectable and variable illumination to allow easy readings of all instruments and controls on the control panel.

3.6.4 Operator remote capabilities. The BPU control system shall have remote operating capability to allow the operator to remotely control and operate up to 12 BPUs through a single device from at least 250 feet away. Any cables, connectors, or equipment (except PC) for remote operation shall be included with each BPU, stored within the enclosure.

3.7 Trailer. The BPU engine-generator shall be mounted on a towable trailer which shall be of the four or six wheel type and shall meet all requirements of SAE AS8090 for Type II, Group C mobility, except that a six wheel, three axle trailer may be provided. (It is noted that SAE AS8090 does not provide for a six wheel trailer.) Trailer lighting (see 3.11 of SAE AS8090) and rear pintle hook (see 3.13 of SAE AS8090) are not required.

3.7.1 Towbar. The BPU shall be equipped with a towbar that has a lunette eye in accordance with A-A-52464B and accommodate any pintle hook height of 22-30 inches.