A02 SOW Attachment 1 PPD IECU 24APR2024.pdf

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PERFORMANCE PURCHASE DESCRIPTION (DRAFT)

AIR CONDITIONERS, HORIZONTAL AND VERTICAL COMPACT

NOTE TO POTENTIAL OFFERORS: This a draft document for which the Government is seeking comments from potential offerors. The Government has indicated by notes some specific areas within this draft where comments are sought. But potential offerors may still comment on any or all other verbiage contained within this draft.

1. SCOPE

1.1. Scope. This performance purchase description (PPD) covers a family of compact air conditioners of both horizontal and vertical configurations, corresponding to the units described in the Improved Environmental Control Unit (IECU) Interface Standard. In this PPD, “air conditioner” will be used interchangeably with “Environmental Control Unit,” or ECU.

2. APPLICABLE DOCUMENTS

2.1. General. The documents listed in this section are needed to meet the requirements specified in sections 3 and 4 of this document. This section does not include documents cited in other sections of this document 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 documents cited in sections 3 and 4 of this document, whether or not they are listed.

2.2. Government documents.

2.2.1. Specifications and standards. The following documents form a part of this PPD to the extent specified herein.

FEDERAL STANDARDS

FED-STD-313 - Material Safety Data, Transportation Data, Disposal

Data for Hazardous Materials Furnished to Government Activities

DEPARTMENT OF DEFENSE

MIL-STD-310 - Standard Practice Identification Marking of U.S.

Military Property MIL-STD-461 - Requirements for the Control of Electromagnetic

Interference Characteristics of Subsystems and Equipment

MIL-STD-810 - Test Method Standard for Environmental Test and Engineering Guidelines

MIL-STD-889 - Dissimilar Metals

MIL-STD-1408 - Improved Family of Military Air Conditioners, General Application Characteristics (Interface Standard for IECUs)

MIL-STD-1472 - Human Engineering MIL-DTL-24308/4 - Connectors, Electric, Rectangular, Miniature, Polarized

Shell, Rack and Panel, Pin Contacts, General Purpose, Class D and G, Crimp Type

(Unless otherwise indicated, copies of federal and military specifications, standards, and handbooks are available from the Standardization Documents Order Desk, Building 4D, 700 Robbins Ave., Philadelphia, PA 19111-5094.)

2.2.2. Other Government documents. The following documents form a part of this PPD to the extent specified herein. Unless otherwise specified, the issues are those in effect on the date of the solicitation.

PUBLICATIONS

SEL Form 1183 - System Safety Design Verification Checklist

(A copy of the above form should be available from the Safety Office overseeing the contract; please contact the Contracting Officer.)

SUPPLY CATALOG

SC 5180-95-C18 - Tool Kit, Refrigeration Equipment (Individual) SC 5180-95-C19 - Tool Kit, Refrigeration Equipment (Base)

(A copy of the above catalog should be available from the Logistician overseeing the contract; please contact the Contracting Officer.)

2.3. Non-Government publications. The following documents form a part of this PPD to the extent specified herein.

AIR-CONDITIONING, HEATING, AND REFRIGERATION INSTITUTE (AHRI)

700 - Specifications for Refrigerants

(Applications for copies should be addressed to the Air-Conditioning, Heating, and Refrigeration Institute, 2311 Wilson Boulevard Suite 400, Arlington, VA 22201.)

AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI)

C101.1 - Leakage Current for Appliances Note: Government seeks comment on the active standard regarding leakage current.

S1.4 - Sound Level Meters – Part 1: Specifications

S1.11 - Octave-band and Fractional-octave- band Filters – Part 1: Specifications

S1.40 - Specifications and Verification Procedures for Sound Calibrators

AMCA STD 210 - Laboratory Methods of Testing Fans for Certified Aerodynamic Performance Rating

Z535.4 - Product Safety Signs and Labels

(Application for copies should be addressed to the American National Standards Institute, 1430 Broadway, New York, NY 10018.)

AMERICAN SOCIETY OF HEATING, REFRIGERATING, AND AIR-CONDITIONING

ENGINEERS, INC. (ASHRAE)

Standard 16 - Methods of Testing for Rating Room Air Conditioners and Packaged Terminal Air Conditioners

Standard 37 - Methods of Testing for Rating Electrically Driven Unitary Air-Conditioning and Heat-Pump Equipment

(Application for copies should be addressed to ASHRAE Publication Sales, 1791 Tullie Circle NE, Atlanta, GA 30329.)

AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME)

Y14.5 - Dimensioning and Tolerancing BPVC.IX - Boiler and Pressure Vessel Code, Section IX, Qualification Standard for Welding, Brazing, and Fusing Procedures; Welders; Brazers; and Welding, Brazing, and Fusing Operators

(Application for copies should be addressed to the American Society of Mechanical Engineers, 345 East 47th St., New York, NY 10017.)

AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM)

B280 - Standard Specification for Seamless Copper Tube for

Air Conditioning and Refrigeration Field Service

AMERICAN WELDING SOCIETY (AWS)

B2.2 - Specification for Brazing Procedure and Performance

Qualification D1.1 - Structural Welding Code - Steel D1.2 - Structural Welding Code - Aluminum

(Application for copies should be addressed to the American Welding Society, 550 NW LeJeune Road, PO Box 351040, Miami, FL 33135.)

COMMERCIAL ITEM DESCRIPTION

A-A-50271 - Plate, Identification

NATIONAL FIRE PROTECTION ASSOCIATION (NFPA)

70 - National Electrical Code (NEC)

(Application for copies should be addressed to National Fire Protection Association, Battery March Park, Quincy, MA 02269.)

SOCIETY OF AUTOMOTIVE ENGINEERS (SAE)

AMS-STD-595 - Colors used in Government Procurement AS33611 - Tube Bend Radii AS34501C - Connectors, Receptacle, Electrical, Wall Mounting, Rear Release, Crimp Contact, AN Type AS34561A - Connectors, Plug, Electrical, Rear Release, Crimp

Contact, AN Type AS50151C - Connectors, Electrical, Circular Threaded, AN Type, General Specification for J184 - Qualifying a Sound Data Acquisition System J429 - Mechanical and Material Requirements for Externally

Threaded Fasteners J492 - Rivets and Riveting J533 - Flares for Tubing J1362 - Graphical Symbols for Operator Controls and Displays on Off-Road Self-Propelled Work Machines

(Application for copies should be addressed to the Society of Automotive Engineers, 400 Commonwealth Drive, Warrendale, PA 15096.)

UNDERWRITERS LABORATORIES (UL)

969 - Standard for Safety Marking and Labeling Systems

(Application for copies should be addressed to Underwriters Laboratories Inc., 12 Laboratory Drive, Research Triangle Park, NC 27709-3995.)

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. Description. The air conditioners described herein are intended primarily for use in mobile tactical electronics shelters and will primarily be powered by tactical generators. The air conditioners shall:

a. be compatible with the requirements of operation in biological and chemical warfare environments as set forth herein.

b. have mounting holes as shown in the Interface Standard.

c. be provided with mounting hardware, which will interface with the mounting holes

(see 6.2).

d. allow input power connection per AS50151C, AS34501C, and as shown in the

Interface Standard. Power connectors shall be equipped with tethered environmental covers.

e. be provided with mating power connector per AS50151C, AS34561A (see 6.2).

f. include a cover for the condenser side of the unit as described in 3.11.5.

g. withstand a storage temperature of -60 to 160 °F.

h. withstand a continuous operating temperature of 0 to 125 °F for cooling (or -25/50 to

125 °F for some units) and -50 to 80 °F for heating.

i. meet Rain, Salt Fog, and Sand and Dust requirements specified in MIL-STD-810.

j. be capable of operating on the electrical power supplies with voltage and frequency variations as specified herein.

k. be equipped with a re-useable filter for the evaporator return air.

l. be suitable for face mounting to walls, ducts, or plenums of the shelter, without protrusions that prevent or impair the ability to environmentally seal the interface with foam gaskets or similar.

m. be suitable for mounting in pairs, side by side, with minimal spacing between (i.e., as little as 3 inches).

n. be suitable for operation during transportation, if required, as cited in the solicitation (see 6.2.l).

3.1.1. Interface Standard. The air conditioners shall be in accordance with the IECU Interface

Standard, and as specified herein. No deviation from the prescribed dimensions or tolerances is permissible without prior approval of the contracting officer. Any data (e.g., shop drawings, layouts, flow sheets, and processing procedures) prepared by the contractor or obtained from a vendor to support fabrication and manufacture of the production item shall be made available for inspection by the contracting officer upon request.

3.1.2. Weight. The weight of the ECU with a full refrigerant charge and all ancillary parts, specified in 3.1, shall not exceed the weight noted in the Interface Standard for that configuration.

3.2. (not used)

3.3. Performance.

3.3.1. Cooling capacity. The minimum net total cooling capacity and the minimum net sensible cooling capacity shall be as stated in the Interface Standard. The ECU cooling capacity shall be tested while operating against an external static pressure differential between the inlet and discharge grille, as stated in the Interface Standard (see Evaporator Airflow for the required external static pressures), and at the conditions stated in Table I.

TABLE I. Cooling Capacity Conditions.

Ambient temperature (dry bulb)

Evaporator Inlet temperature (dry bulb)

Evaporator Inlet temperature (wet bulb)

125 °F 90 °F 75 °F

3.3.2. Evaporator airflow. The minimum evaporator airflow shall be as specified in the Interface Standard, with the static pressure differential measured between the inlet grille and the discharge grille.

3.3.3. Cool mode operating temperatures.

3.3.3.1. High temperature operation. After exposure to 125 °F for four continuous hours, the ECU shall start and operate for one continuous hour in the COOL mode with air at no less than 125 °F surrounding the air conditioner.

3.3.3.2. Low temperature operation.

3.3.3.2.1. Coil frost. The ECU shall operate in COOL mode at 55 °F ambient outdoor temperature, without significantly forming frost or ice on the evaporator, with air at 70 °F dry bulb and 60 °F wet bulb entering the evaporator.

3.3.3.2.2. Low temperature operation. After being subjected to 70 °F on the evaporator side, and 0 °F on the condenser side for a period of four hours, the ECU shall start and operate for one continuous hour in the COOL mode, without system warm-up.

3.3.4. Heating.

3.3.4.1. Heating capacity. The minimum heating capacity of the ECU shall be as specified in the Interface Standard. Power consumption shall be not more than as specified in the Interface Standard.

3.3.4.2. Low temperature operation. After being subjected to minus 50 °F for a period of not less than four hours, the ECU shall be capable of start, operate and restart in the heating mode with air at minus 50 °F into the evaporator inlet.

3.3.5. Electrical performance. The ECU shall operate as specified herein when supplied with rated voltage, with up to +10% and down to –5%, and with input frequencies either 50 or 60 Hz.

3.3.5.1. Power and steady-state current. The maximum total power consumption, minimum power factor, and maximum steady-state current of the ECU operating in the HEAT and COOL modes shall be as specified in the Interface Standard.

3.3.5.2. Inrush current. The inrush current for the ECU, including startup and thermostatic cycle, shall not exceed the maximum current specified in the Interface Standard.

3.3.5.3. Total harmonic distortion. The Total Harmonic Distortion (THD) of the current waveform imposed on the input power line by the ECU shall not exceed 25%.

3.3.6. Inclined operation. The ECU shall be capable of operating in COOL mode without malfunction when the base of the ECU is positioned 10 degrees from the horizontal in any plane.

During inclined operation, the condensate drain line shall remain effective in disposing of condensate. There shall be no evidence of moisture “carryover” in the airflow leaving the conditioned air outlet. All condensate shall drain to the exterior of the outdoor side of the ECU.

The exterior opening of the condensate drain shall be sealable with a threaded plug.

3.4. Controls.

Note: Government seeks comment on whether digital controls and indicators for diagnostics should be acceptable alternatives to the analog controls described below and diagnostics described in 3.17.2.3.1. And what would the size, shape, gloved operation, extreme temperature operation requirements look like in order to meet the same functional and human interface needs?

3.4.1. User Interface. Detent controls shall be selected whenever the operational mode requires control operation in discreet steps. Colors of safety critical indicators shall be yellow for caution, and red for danger. Other functional controls shall be black. Stops shall be provided at the beginning and end of the range of, or limits of, positions if the control is not required to, or should not be operated beyond, the indicated end positions or specified limits. Direction of control movement shall be consistent with the effect of change. For example, the movement of a control forward, clockwise, to the right, up or pressing a control, shall turn the equipment or component on, cause the quantity to increase, or cause the effected element to move forward, clockwise, to the right, or up. Controls shall be designed and located so that they are not susceptible to being adjusted accidentally, particularly critical controls whose inadvertent operation might cause damage to equipment, injury to personnel or degradation of system functions. An indication of control activation shall be provided (e.g., snap feel, audible click, or indicator light illumination).

3.4.1.1. Mode selector control. Operation of the ECU shall be controlled by a single mode selector switch. The mode selector switch shall have four modes of operation: OFF, VENT, COOL, and HEAT. The mode selector switch shall control operation of the ECU as follows (in a general sense without regarding actions due to the thermostat, safety cutouts, or other control actions). The “OFF/RESET” label for the mode selector switch, as shown on the control panel in the Interface Standard, is open to modification. If the unit has no resettable/self-repair functions that would be enabled by cycling the unit on/off, then the switch may be labeled with “OFF” only.

a. When the control is in the OFF position, the electrical heaters, the fan motors, and the compressor shall be de-energized regardless of the position of the thermostat.

b. When the control is in the VENT position, the evaporator fan motor shall be energized. The compressor, condenser fan motor, and the electric heaters shall be de-energized regardless of the temperature selection control setting.

c. When the control is in the COOL position and the thermostat at the coolest setting, the evaporator fan motor, the condenser fan motor, and the compressor shall be energized. The electric heater shall be de-energized.

d. When the control is in the HEAT position and the thermostat at the warmest setting, the evaporator fan motor and the electric heaters shall be energized. The condenser fan motor and the compressor shall be de-energized.

3.4.1.2. Conditioned-air thermostat. The thermostat shall allow operators to regulate the conditioned space temperature approximately between 60 to 90 °F. The thermostat shall have two labels, "COOLER" and "WARMER", to indicate direction of proper operation. The unit shall not allow continued cooling when the evaporator return air drops below 50°F.

3.4.1.3. Control box. The ECU shall have a control box, which shall be capable of operating the ECU both remotely and when installed in the ECU. The mode selector switch and temperature selection control shall be mounted in the control box. The control box shall be capable of being mounted on the face of the evaporator section as shown in the Interface Standard. It shall be designed so that it can be easily removed and replaced in the evaporator section; and removal of the remote control shall not disturb the airflow of the unit (i.e., removal of the control box shall not create an open hole such that general airflow pattern will change). No conductors connected to the remote-control box shall exceed 30 volts.

3.4.2. High pressure cutout. A switch shall de-energize the compressor before the discharge pressure exceeds the compressor manufacturer’s specified maximum operating pressure. The switch shall have a manual reset actuator located as shown in the Interface Standard. When this reset is activated, and the pressure has returned to the manufacturer’s recommended range, the switch shall allow the compressor to be re-energized.

3.4.3. Low pressure cutout. A switch shall de-energize the compressor when the suction pressure reduces below the compressor manufacturer’s specified minimum operating pressure.

When the pressure has returned to a manufacturer’s recommended range, the switch shall re-energize the compressor either manually or automatically.

3.4.4. Heater high limit cutout. A switch shall de-energize the heater in the HEAT mode when the interior of the evaporator compartment reaches between 180 and 250 F. All materials used in the evaporator compartment shall be able to withstand this temperature without smoking, charring, becoming brittle, or otherwise becoming damaged. The switch shall automatically reset when the temperature declines to a range between 80 and 120 F.

3.5. Refrigeration system.

3.5.1. Refrigeration system. The system shall be of the vapor-compression type, using refrigerant(s) compliant with current EPA regulations as cited in the solicitation (see 6.2.k). The purity of the refrigerant shall be in accordance with ARI 700. The system shall use a thermal expansion valve to control the refrigerant flow to the evaporator. All refrigeration system components shall be compatible with the refrigerant and lubricant. The ECU shall include all necessary safety features for the refrigerant. Note-Government seeks input on what safety features are required and which entity governs those safety features.

Note: The Government seeks input on feasibility and maturity of potential improvements for global warming potential in the IECUs; what are near and long term regulatory and industry requirements for refrigerants; and

Note: The Government seeks input on what are the likely refrigerants to be selected in the design of IECUs. Some examples could be seeking waivers to use 410A, using high pressure A2L refrigerants (R454B, R32), or medium pressure A1 units (R513A).

Note: The Government seeks input on the feasibility and maturity of refrigerant flexibility technology and/or refrigeration-agnostic IECUs. The concept is an IECU that can use multiple refrigerants without needing significant changes to IECU design when a refrigerant is phased out.

3.5.2. Restart. The ECU shall be capable of being shut down and restarted within 10 seconds at any operating condition; if any component is designed with a time delay, that time delay process must begin within the stated 10 seconds.

3.5.3. Refrigerant leakage. The entire refrigerant system shall be free from any detectable leakage of greater than or equal to 0.1 ounce per year. The entire refrigerant system shall withstand the maximum pressure without deformation of any component or any detectable leakage.

3.5.4. Pressure relief. The ECU shall have a mechanism to relieve pressure in a safe location and manner. This mechanism shall activate above the compressor manufacturer’s specified maximum operating pressure and shall be resettable.

3.5.5. Refrigerant tubing. Tubing shall be installed such that it does not contact any adjacent component or structure. All tubing bends shall have a minimum centerline bend radius of twice the tube diameter in accordance with SAE AS 33611. Tube ends shall be flared at all flare nut joints in accordance with SAE J533, single 45° Flare.

3.5.6. Charging lines. Two service connection lines, with standard fittings for the refrigerant used, shall be provided on the condenser section, one for high side (discharge) and one for low side (suction). The lines shall be mounted such that they can be accessed through an access panel. Sufficient clearance shall be provided so that a manifold gauge can be connected to these lines by hand. Captive protective caps shall be provided for these lines. The external side of the access panel shall be marked “SERVICE VALVES”. The lines shall be labeled “DISCHARGE” and “SUCTION” with 0.25-inch letters in accordance with the labeling criteria specified herein (see 3.16.4.2).

3.5.7. Sight glass. A sight glass shall be easily visible and protected from damage.

3.6. Vibration. When subjected to MIL-STD-810, General Vibration Procedure, Restrained Cargo Category, Transportation scenario (non-operational during the test), the ECU shall show no evidence of structural damage, misalignment or malfunction of components, leaks, fractures, abnormal vibration, or any other irregular operation.

Note: The Government seeks input on the feasibility of the requirements below for “cool on the move” capability.

The IECUs shall be designed to be controllable and function properly and reliably without damage or degradation when operating aboard a vehicle, shelter or container being transported on in all modes of transport in military operations. Shelters or containerized systems the IECUs will be integrated with are often tested on the Perryman Road Test, Munson Gravel Road Test, Munson Belgian Block Course, 2-inch washboard course, and radial washboard course with 2–4” waves. Other factors to be considered when designing for cool-on-the-move capability include operability or automatic shutdown at severe vehicle angles, protection of the condenser and fans from airborne objects and dust, accounting for winds from various angles, and protection from precipitation including rain, sleet, and snow. As currently envisioned, the vehicle or integrated system will provide power to the IECU in accordance with the Interface Standard. On the move performance testing shall use the methods described in ARI-1110 2024, the Air Conditioning & Refrigeration Institute’s “Performance Rating of Vapor Compression Transport Refrigeration Units.”

3.7. Shock. When subjected to MIL-STD-810, procedure for Bench Handling, the ECU shall show no evidence of structural damage, misalignment or malfunction of components, leaks, fractures, abnormal vibration, or any other irregular operation.

3.8. Electromagnetic Interference (EMI). The ECU shall meet all test method requirements specified herein, per MIL-STD-461. When specific application requirements are specified in MIL-STD-461, “Ground” and “Army” shall apply.

3.8.1. Radiated. Electromagnetic field emissions shall not be radiated from the ECU or any interconnecting cables in excess of those shown in Method RE102, electric field, 2 MHz to 1 GHz.

3.8.2. Conducted. Conducted emissions on power leads shall not exceed the applicable values shown in Method CE102, power leads, 10 kHz to 10 MHz.

3.8.3. Susceptibility. If the unit contains any circuit cards or electronic controls, the unit shall not be susceptible to conducted or radiated EMI in accordance with the following tests:

a. Method CS101, power leads, second harmonic to 150 kHz.

b. Method CS114, bulk cable injection, 10 kHz to 200 MHz.

c. Method RS103, electric field, 30 MHz to 18 GHz.

3.9. Noise. The noise levels produced by the ECUs shall comply with the following:

a. The noise level on the evaporator side shall not exceed 76 dB(A) at one meter from any point on the perimeter of the evaporator side of the housing.

b. The noise level on the condenser side shall not exceed 85 dB(A) at one meter from any point on the perimeter of the condenser side of the air conditioner.

3.10. Reliability and maintainability.

3.10.1. Reliability. The minimum mean time between essential function failure (MTBEFF) shall be 2,100 hours, with 80% confidence level. Essential functions are the minimum operational tasks that the system must be capable of performing to successfully complete its mission. The loss of an essential function, regardless of when it occurs, will be considered as an essential function failure (EFF). The two essential functions for the IECU are: (a) The IECU must provide thermostatically controlled, clean, cooled, and de-humidified air at its rated output, and (b) The IECU must provide thermostatically controlled, clean, heated air.

3.10.2. Maintenance ratio. When tested as specified in 4.3.10.2, the air conditioner shall have a maintenance ratio of not more than 0.017 maintenance man-hour per operating hour.

3.10.2.1. Scheduled maintenance. The air conditioners shall not require scheduled maintenance more often than once every 250 hours of operation.

3.11. Evaporator and condenser compartment.

3.11.1. Compartment design. The air conditioner design shall alleviate ingestion of airborne contaminants into the evaporator compartment from the condenser side. Preventive measures shall include assuring that the evaporator compartment is never at a lower pressure than the condenser compartment (i.e., evaporator is a push-through design).

3.11.2. Evaporator compartment air leakage. The air leakage from the evaporator compartment shall not exceed 20 standard cubic feet per minute (scfm) when the evaporator compartment is subjected to an internal static pressure of 1.0-inch water gauge (wg).

3.11.3. Evaporator directional louvers. The air conditioner shall have directional louvers on the evaporator outlet. The louvers shall be adjustable such that air can be directed up or down, and right or left.

3.11.4. Condenser exhaust louvers. Condenser exhaust louvers may be used.

3.11.5. Condenser cover. A removable cover shall be attached to the air conditioner for use during transportation and storage. The cover shall be capable of being rolled up and secured in place and of being unrolled and fastened easily (e.g., by zipper or quarter-turn fastener) to cover all condenser openings. The cover shall be waterproof, flame resistant, and oil resistant. The color shall be identical to the color of the air conditioner (see 6.2). The minimum initial breaking strength shall be 225 lbs. The minimum tearing strength shall be 38 lbs.

3.11.6. Fresh-air flow. A fresh-air inlet with a damper shall be provided per the Interface Standard. This assembly shall provide fresh air from the exterior of the air conditioner and the inlet shall be installed in the condenser section of the air conditioner. When the evaporator fan is operating, outside air shall flow into the evaporator compartment when the damper is opened, with a flow rate not less than:

a. 35 scfm for 9,000 Btu/hr ECU

b. 70 scfm for 18,000 Btu/hr ECU

c. 140 scfm for 36,000 Btu/hr ECU

The damper shall be controlled from the indoor side of the air conditioner and shall be labeled to indicate fully open and fully closed positions. The damper shall be as close as is feasible to the exterior opening of the inlet to alleviate NBC (Nuclear, Biological, and Chemical) contamination of the ECU and to facilitate NBC decontamination of the inlet and damper. The damper shall be designed so that normal operation position is closed, but it has the capability to be locked open.

When closed, no air shall pass through or around the damper.

3.12. Electrical system. The air conditioner shall be designed to comply with the National Electrical Code (NFPA 70) and as specified herein.

3.12.1. Wiring. Cables and wires shall be secured to ensure that cables or wires do not hinder or obstruct equipment maintenance, and to prevent chaffing from contact with adjacent structures. Cables and wires shall not be spliced at any point throughout their cable/harness runs.

Electrical isolators shall be used between all wiring and metal components to prevent abrasive action to wire insulation. Cables shall be routed neatly, with cable bundles attached to bulkhead walls or other permanent structures using cable clamps or tie wraps at no greater than 6-inch intervals. Cables shall be routed preferably using 90-degree angles to change directions. Any connectors used in the cabling shall be either clamped or supported. Wiring shall minimize the possibility of water intrusion damage by using of waterproof connectors, drip loops, sealants, gaskets, anti-capillary wire, and/or separation of line voltage and signal voltage wires as suitable.

3.12.2. Power connector. The connector for power input to the air conditioner shall be as stated in the Interface Standard, or an equivalent commercially available connector, and shall include a captive cover. It shall be possible to connect the power leads to the air conditioner on the evaporator face and the condenser face. The units shall be designed so that only one power input connector can be used at a time; the second power input shall not be energized when the other is in use. Power connectors shall use safe compatible alternatives to Cadmium plating, such as Nickel-PTFE.

3.12.3. Power conductor color-coding. All power conductor colors shall be in accordance with NEC. For three phase systems, L1 shall be Black, L2 shall be Red, and L3 shall be Orange.

Low voltage conductors shall be Blue.

3.12.4. Wire marking. All wiring shall be marked to indicate points of origin and ending using nomenclature that is consistent with the electrical schematics and wiring diagrams supplied with the ECU.

3.13. Safety.

3.13.1. General. The air conditioner shall be designed so that under all conditions of normal use (installation, operation, and maintenance) and under likely fault conditions (including human error), it protects against the risk of electric shock and other hazards. All hazards shall be eliminated or reduced to the lowest risk level practicable using methods in the following order of precedence: design; incorporation of safety devices; incorporation of warning devices; and procedures/training. Catastrophic or critical hazards shall not rely solely on warnings, cautions, or procedures/training for control of risk. All safety hazards not eliminated through design shall be addressed in the appropriate technical manuals. Information regarding hazard-avoiding procedures and safety warning labels on equipment shall be included in all manuals. The air conditioner shall comply with SEL Form 1183, which shall be appended to the Safety Assessment Report.

3.13.2. Electrical safety.

a. Any component with voltages exceeding 30V shall not be accessible to operators.

Stored electrical energy will not be exposed to operators while disconnecting the system from its power source.

b. Protection will be provided to personnel during maintenance and repair to prevent unintentional contact with voltages exceeding 30V. Capacitors shall discharge to less than 30V and 20J energy prior to maintainer access.

c. Equipment leakage current to ground shall not exceed 3.5 mA, when tested IAW ANSI C101.1. Redundant equipment grounding conductors may be used to reduce the leakage current. Hinges and slides shall not be relied upon as the sole means of grounding.

d. The ECU shall be provided with a means at the ECU (i.e., not at the remote-control location) to prevent accidental system activation while system is configured for remote operation. The design of the connector shall be such that the operator is not exposed to electrical shock or burns when prescribed disconnecting methods are used.

3.13.3. Mechanical safety. The following shall be incorporated into the ECU design:

a. The equipment shall provide maximum access and safety to personnel during installation, operation, and maintenance.

b. The ECU shall be designed so that it can be moved, handled, and lifted safely. Single person lift limit for user replaceable components is 37 pounds. Replaceable components exceeding single person lift limit shall be labeled with the total weight and shall be supplied with lifting eyes.

c. Pressurized systems shall be provided with relief valves which vent in a safe location and manner.

d. All rotating or reciprocating parts and parts subject to high operational temperatures that are of such nature or so located as to be a hazard to operating personnel shall be guarded or insulated to the extent necessary to eliminate the hazard. Protective guards shall not have openings larger than 1/2 square inch.

3.13.4. Environmental/Chemical safety.

a. Hazardous materials that can be exposed to personnel or the environment during any operational (to include fabrication, transportation, and setup/teardown) procedure, maintenance procedure, or as a result of damage to the equipment, or require special disposal procedures, shall be kept to a minimum. Non-toxic/environmentally acceptable substitutes shall be used whenever possible.

b. Use of any hazardous materials and disposal of hazardous waste, shall be in accordance with current applicable Federal, State, or local laws, regulations, standards, and requirements. Hazardous material exposure to personnel shall be controlled to levels below the OSHA Permissible Exposure Limits, the American Conference of Governmental Industrial Hygienists, Inc (ACGIH) Threshold Limit Values, or other applicable standard.

3.13.5. Noise related hazards. Operator exposure to noise shall be limited to 85 dB(A) irrespective of exposure time. A noise level evaluation shall consider exposure to noise during maintenance with panels removed/opened. Warnings shall be provided (including headsets, handsets, earplugs, etc.) where noise levels exceed the above requirements during maintenance.

3.14. Lift provisions. The air conditioner shall have provisions for lifting. The 9K and 18K units shall have handles for carrying the air conditioner, located as per the Interface Standard.

The minimum inside dimensions of the handles shall be 4.75 inches wide by 2.5 inches high. The 36K units shall have sling lifting rings, with a minimum interior diameter of 1.75 inches, and located as per the Interface Standard. The handles and lifting rings shall be non-protruding and self-retracting.

3.15. Material protection. The ECU shall be fabricated from compatible materials, inherently corrosion resistant or treated to provide protection against the various forms of corrosion and deterioration that may be encountered in any of the applicable operating and storage environments to which the ECU may be exposed. Protection against corrosion shall be in accordance with SAE ARP 1481 and J447.

3.15.1. Dissimilar metals. Dissimilar metals shall not be used in intimate contact with each other unless protected against galvanic corrosion.

3.15.2. Recovered materials. For the purpose of this requirement, recovered materials are those materials which have been collected from solid waste and reprocessed to become a source of raw materials, as distinguished from virgin raw materials. The components, pieces, and parts incorporated in the ECUs may be newly fabricated from recovered materials to the maximum extent practicable, provided the ECUs meet all other requirements of this specification. Used, rebuilt, or remanufactured components, pieces and parts shall not be incorporated into the ECU.

3.15.3. Fungus and moisture resistance. The electrical circuitry, including all components and connections shall be protected from the effects of fungus growth and moisture. Hermetically sealed components may not be treated for fungus growth and moisture.

3.15.4. Externally exposed surfaces. All externally exposed surfaces of the ECU shall be cleaned, treated, and painted, except when such paint is undesirable. For example, sight glass and various informational plates shall not be painted because painting them will make those parts ineffective. Unless otherwise specified, the paint shall be a chemical agent resistant coating (CARC), color complying with AMS-STD-595 green 383 or tan 686. Prior to painting any units, the contractor shall be able to provide documentation showing that the CARC paint is certified.

The contractor shall also use a CARC paint system from an Army Research Laboratory qualified vendor. (A list of qualified vendors can be obtained by contacting the US Army Research Lab, Weapons and Materials Directorate, ATTN: AMSRL-WM-M, Aberdeen, MD 21005-5069.)

The CARC final film shall be applied over a compatible lead and chromate free and chemical agent resistant epoxy primer. Surface preparation and painting shall be in accordance with best commercial practices. The equipment shall be marked with the word “CARC” stenciled in CARC paint in close proximity to the nameplate. A contrasting color shall be used for the marking (e.g. black marking on a green surface). The letters shall be no less than one inch high.

3.15.5. Interior surfaces. All sheet metal interior to ECU shall be cleaned and treated. Cables, wiring, controls, heater coils, refrigerant coils, refrigerant system components, electrical system components, refrigerant lines and hoses, identification plates, instruction plates, data plates, schematics and wiring diagram, control panel, labels, air filters, connectors, refrigerant connectors, interior nuts, bolts, and washers, and any rubber components, plastics or fabric shall not be painted.

3.16. Marking and labeling.

3.16.1. General.

a. Marking shall be as permanent as the normal life expectancy of the marked item and shall be capable of withstanding the environmental conditions and cleaning procedures for the marked item.

b. The method of marking shall be such that it will not adversely affect the life and utility of the marked item.

c. All markings shall be capital letters with letter height of at least 0.16-inch, except as specified herein, or shall be easily interpretable icons. Numerals shall be Arabic, except when Roman numerals are used for type designation in specifications or standards. Text type shall be Gothic No. 2 or equivalent.

d. Variable controls, such as the temperature controls, shall be labeled with a symbol for a continuously variable control conforming to SAE J1362.

e. No deterioration, corrosion, or damage to any marking, labels, information plates, or the plates and fasteners utilized for marking shall be observed when the air conditioner is subjected to the conditions specified herein.

f. Marking materials creating hazardous conditions shall not be used.

3.16.2. Information plates. The following plates shall be permanently attached to the air conditioner: identification plate, refrigeration system schematic, electrical schematic, and wiring diagram. If any of the specified character size yields respective plate size beyond practical limit, that character size will be reduced accordingly.

3.16.2.1. Identification plate. The identification plate shall conform to A-A-50271, Composition A (Class 2) or C. The marking color shall be white or silver on a black background.

All characters on this plate shall be at least 1/8-inch high. The identification plate shall be permanently attached to the housing in a location where it is visible. It shall include the following information:

a. Item nomenclature (e.g., AIR CONDITIONER, 9,000 BTU/HR HORIZONTAL

COMPACT, 115 V, 1 PH, 50 AND 60 HZ)

b. Date of manufacture (e.g., MAR 2004)

c. Contract number

d. National Stock Number

e. Type of refrigerant (e.g., R-410A)

f. The refrigerant charge amount (e.g., 3 LB 6 OZ)

g. Weight (e.g., 150 LB)

h. Notice of Warranty

i. Technical Manual number

j. Manufacturer’s name

k. CAGE code

l. Part number

m. Serial number

n. IUID symbol in accordance with MIL-STD-130, UII Construct #2, Format Code 06, with CAGE, Part number, and Serial number (17V + 1P + S)

3.16.2.2. Schematics and wiring diagram. An electrical schematic, refrigeration system schematic, and wiring diagram shall be photoetched on plates conforming to A-A-50271, Composition C. All characters on these plates shall be at least 3/32-inch high. These plates shall be permanently attached to the air conditioner housing in a location such that they are visible.

Identification markings of control devices and connections shall be shown on all diagrams and shall coincide with markings on all items, which are identified in the applicable schematic or wiring diagram.

3.16.3. Safety markings and labels. Safety markings and labels, in accordance with ANSI Z535.4, shall be provided identifying any potential hazards to personnel. Safety labels shall comply with the durability requirements of UL 1950, paragraph 1.7.15 and/or UL 969. Voltages in excess of 30V shall use the signal word “WARNING”. All characters on these plates should be at least 1/4-inch high whenever space allows. Markings shall be readily visible. They should not be on a part which can be removed from the unit (e.g., access panel or door).

3.16.4. Labeling.

3.16.4.1. General. Labels shall be provided to identify operator or maintainer-related controls, displays, access covers, refrigerant lines, and cable connectors, except where it is obvious to the operator what an item is and its function and operation. Controls shall be labeled to indicate functional result of control movement (e.g., “ON”, “OFF”, “COOLER”, etc.). All labels shall be capital letters with letter height of at least 0.16 inch or shall be easily interpretable icons. Labeling marking shall be directly on the item itself, or by mounting of a label with the pertinent information.

3.16.4.2. Items requiring labeling. At a minimum, the following items in the air conditioner shall be labeled:

a. Refrigerant charging valves. The suction-side and discharge-side valves shall be labeled as per 3.5.6.

b. Refrigeration components. At a minimum, refrigeration components shall be labeled with identification marking correlating to the refrigeration system schematic. They shall also be labeled with the component’s vendor information and mechanical and electrical characteristics to the extent that it is practicable.

c. Electrical components. At a minimum, electrical components shall be labeled with identification marking correlating to the electrical schematic and wiring diagram.

They shall also be labeled with the component’s vendor information and electrical characteristics to the extent that it is practicable.

d. Altered items. The contractor shall label the item with, at a minimum, a contractor-unique parts number for use in obtaining spare and repair parts. The item shall also be labeled with the component’s mechanical and electrical characteristics to the extent that it is practical. The item vendor’s information shall not be removed.

e. Other repairable and replaceable components shall be labeled with unique part numbers for use in obtaining spare and repair parts.

3.16.4.3. Human factors for labeling.

3.16.4.3.1. Standardization. Labels shall be located in a consistent manner throughout the equipment.

3.16.4.3.2. Abbreviations. Only standard abbreviations shall be used and only if complete words will not fit in the available space. Capital letters shall be used. Periods shall be omitted except when needed to preclude misinterpretation. The same abbreviation shall be used for all tenses and for both singular and plural forms of a word.

3.16.4.3.3. Label colors. The label color shall be either white text on a black background, or black text on a green No. 383 background, in accordance with AMS-STD-595.

3.17. Human performance and human factors engineering (HFE). The air conditioner shall comply with all of the following human performance and HFE criteria:

3.17.1. Human performance. The air conditioner shall be operable and maintainable by 5th through 95th percentile soldiers dressed in the Battle Dress Uniform (BDU), cold-wet weather protective clothing, and protective ensembles for Mission Oriented Protective Posture (MOPP) Levels I through IV. The air conditioner shall also minimize personnel and training requirements.

3.17.2. HFE. The air conditioner design shall conform to Army accepted HFE criteria. The major aspects of those criteria relevant to air conditioners are:

3.17.2.1. Simplicity of design. The ECU shall represent the simplest design consistent with functional requirements and expected service conditions. It shall be capable of being operated, maintained, and repaired in its operational environment by personnel with a minimum of training.

3.17.2.2. Hot surfaces. Any surfaces which, in normal operation, expose personnel to temperatures in excess of 140 °F as a result of inadvertent contact or 120 °F during handling shall be appropriately guarded. Surface temperatures induced by climatic environment are exempt from this requirement.

3.17.2.3. Design for maintainer. The ECU shall be designed for ease of maintenance.

Standard parts shall be used whenever practicable. Mission critical items, which require rapid maintenance, shall be most accessible. When relative criticality is not a factor, items requiring most frequent access shall be most accessible. High failure rate items shall be accessible for replacement without moving non-failed items. Items shall be so located and mounted that access to them can be achieved without danger to personnel from electrical charge, heat, moving parts, chemical contamination, etc. Those items that require access shall be located away from structural frame, if possible, to enhance accessibility. The air filter shall be accessible without having to remove the top cover of the unit or having to remove the unit from its mounting bracket.

3.17.2.3.1. Embedded diagnostics. A diagnostic system shall be embedded in the ECU. This system shall allow an individual to determine the ECU’s operational state with no more removal than one external panel or cover of the ECU which shall not require dismounting of the ECU from its normal operation setup. The diagnostic system shall use visual indicators or low voltage test points that can be easily read with a standard multimeter. At a minimum, the diagnostic system shall allow determination of (1) discharge and suction pressures, (2) inlet and outlet evaporator air temperatures, and (3) evaporator coil temperature. A failure of this diagnostic system shall not affect the ECU operation.

3.17.2.3.2. Special tools. The IECUs shall be maintainable using only the tools specified in SC 5180-95-C18 and SC 5180-95-C19, supplemented by those tools required for the required refrigerant (see 6.2.k). The refrigerant tools include: (1) Refrigerant Recovery Machine, (2) Manifold Gauge with Hoses, and (3) Leak Detector. NSNs are yet to be determined. The list for supply catalogs and tool kits available are provided at www.ldac.army.mil.

3.17.2.3.3. Error proof design. To assist assembly and installation, and preclude improper assembly or installation, the system shall incorporate the following:

a. Physical measures to preclude interchange of items of a same or similar form that are not in fact functionally interchangeable.

b. Physical measures to preclude improper mounting of units or components.

c. Measures (e.g., coding) to facilitate identification and interchange of interchangeable items. Measures (e.g., alignment pins) to facilitate proper mounting of items.

d. Measures to ensure that identification, orientation, and alignment provisions include cables and connectors.

All parts having the same part number shall be functionally and dimensionally interchangeable.

Interchangeable parts are defined as two or more parts possessing such functional and physical characteristics as to be equivalent in performance and durability and capable of being exchanged one for the other without alteration of the parts themselves or adjoining parts, except for adjustment, and without selection for fit or performance.

3.17.2.3.4. Captive fasteners. Captive fasteners shall be used where dropping or loss of such items could cause damage to equipment or create a difficult or hazardous removal problem.

Captive fasteners shall also be provided for access covers, the remote-control box, and other items which require frequent removal.

3.17.2.3.5. Access panels. The design shall include mechanisms to prevent inadvertent loss of opened and/or removed panels (e.g. hinges or linkage cable/chain).

3.18. Workmanship.

3.18.1. Metal fabrication. Metal used in fabrication shall be free from kinks and sharp bends.

The straightening of material shall be done by methods that will not cause injury to the material.

Corners shall be square and true. All bends shall be made by controlled means to ensure uniformity of size and shape. Precaution shall be taken to avoid overheating materials. Heated steel shall be allowed to cool slowly. All surfaces shall be free of burrs. All exposed edges and corners shall be rounded to a minimum of 0.03-inch radius. All exterior edges and corners that present a personal safety hazard or potential damage to equipment during usage shall be suitably protected or rounded to a minimum radius of 0.25-inch.

3.18.2. Welding. Welding shall be done in accordance with AWS D1.1, AWS D1.2, and/or ASME Boiler and Pressure Vessel Code, as applicable.

3.18.3. Brazing. Brazing shall be done in accordance with AWS B2.2 or ASME Boiler and Pressure Vessel Code, as applicable.

3.18.4. Bolted connections. Bolt holes shall be accurately formed and shall have burrs removed. Washers or lock washers shall be provided where necessary. Matching thread areas securing bolts conforming to SAE J429 or capscrews shall be of sufficient strength to withstand the tensile strength of the bolt.