Attachment (A) NNSY DWG 2310-286 20-ton AC Unit Specifications REV. B.pdf

Document No. 2353ZN01 Attachment (A)

NORFOLK NAVAL SHIPYARD DRAWING 2310-286

20-TON AIR CONDITIONING UNIT SPECIFICATION

REVISION B

PURPOSE: The purpose of this solicitation is to provide specifications for the fabrication and testing of 4,000 Cubic-Feet per Minute (CFM) Air Conditioning units with a cooling capacity of 20 Tons (240,000 Btu/h) and minimum heating capacity of 50 kW (170,500 Btu/hr). The A/C units shall be delivered complete and ready for operation. The capacity of the units shall not be less than indicated.

1. OPERATIONAL REQUIREMENTS:

1.1. Airflow:

1.1.1. The units must deliver 4,000 CFM (minimum) at static pressures between 0-16 in w.g.

1.1.2. The units must be capable of varying airflow between 2,000-4,000 CFM via use of a Variable

Frequency Drive (VFD). The unit must operate with unrestricted air delivery without blower motor overload at design static pressures.

1.1.3. The system shall provide automatic variable capacity control requiring only initial temperature and mode selection by operator. Air Conditioning units are to be the “blow through” (i.e. blower pushing air through the evaporator coil) configuration.

1.2. Cooling:

1.2.1. The air conditioning units shall have a rating not less than 20 Tons in accordance with Air

Conditioning, Heating, and Refrigeration Institute (ANSI/AHRI) 210/240 using R-410A refrigerant.

1.2.2. The units shall be equipped to operate in the cooling mode at partial cooling loads, during low outside ambient temperatures down to 40º F without evaporator freeze up and/or compressor damage due to slugging (when operating in a closed circuit where return air at 40º F or above is being cooled). A thermostat solely dedicated to compressor protection is to cause the refrigerant liquid line solenoid valve to close (causing “Pump Down” and refrigerant compressor stoppage) any time the return air temperature (or outside air depending upon A/C unit use) drops below 40º

F. The solenoid valve must not reopen until the return (recirculated or supply) air temperature rises to 45º F.

1.2.3. The air conditioning units must be capable of conditioning 4,000 CFM air at a temperature of

100ºF DB and 78ºF WB down to an average evaporator coil exit temperature of 40ºF DB and 40º

WB at static pressures varying between 0 and 16 inches of water gage.

1.3. Heating:

1.3.1. When operating in heating mode, the unit must have electric heaters with the capacity to add at least 170,500 BTU/hr (50 kW) of heat to the air stream at a flow rate of 4,000 CFM.

SECTION 1 – OPERATIONAL REQUIREMENTS

SECTION 2 – MAJOR COMPONENT REQUIREMENTS

2. MAJOR COMPONENT REQUIREMENTS:

2.1. Blower (Fan):

2.1.1. The blower motor shall be TEFC and the blower shall be direct drive.

2.1.2. The blower motor shall be mounted outside the air stream. The blower motor and blower shall be mounted on a common base adequately supported to minimize vibration.

2.1.3. The blower impeller shall be statically and dynamically balanced. The assembled blower / blower motor shall be operationally tested in place in the unit, by the contractor, to ensure operational vibration limits are ≤ 0.15 in/sec peak velocity or vibration displacement limit of 1.5 mm peak to peak measured on the bearings and free end of blower shaft, if applicable.

2.2. Air Filters:

2.2.1. All air (100%) entering the air conditioning unit shall be filtered at the intake. The filter section shall have 2” deep prefilters and 12” deep 95% efficiency filters as appropriate.

2.2.2. Instrumentation shall be provided to indicate the condition (pressure drop in inches of water across the filters) of the filters. The readout shall be a Magnehelic gage mounted in the control panel. See Section 3.

2.2.3. Access to the filter compartment shall be by hinged access doors. The doors shall be equipped with latches to hold each door in both the open and closed positions. Each door is to be equipped with a heavy duty replaceable type gasket material to minimize leakage to and from the air filter compartment.

2.3. Conditioning Air Section:

2.3.1. The unit shall include a single conditioning air section through which 100% of outside air may be passed for conditioning by cooling or heating as determined by the particular mode of operation selected.

2.3.2. Principle components comprising the air path within the A/C unit are the intake hood, intake plenum, blower, refrigerant evaporator, electric heating section, discharge plenum, discharge hood and the interconnecting duct.

2.3.3. Air Path: The air path interconnecting duct is to be a minimum of 12 gage aluminum. The air path components (i.e. blower, evaporator / heating sections, etc.) are to be a minimum 12 gage aluminum and surface coated to resist the corrosive effects of moist salt air. The entire path must be air tight except for blower shaft seals where 1-2 CFM air leakage will be allowed. All seams and instrumentation probe holes shall either be welded or sealed with a suitable air tight sealer with fasteners to form a positive seal and will hold a minimum of 30” w.g. static pressure.

2.3.4. Air Path Leak Test: The contractor shall perform a duct leak test IAW the requirements of the

Nuclear Air Cleaning Handbook (DOE-HDBK-1169-2003) for Level 2 requirements. Areas to be tested include the air intake, discharge, instrumentation penetrations (with condensate drain suitably plugged) to determine integrity of air path.

2.3.5. Insulation: Leak test is to be completed prior to the installation of the insulation. The air path components and interconnecting duct are to be fully insulated using a minimum one-inch thick industrial type insulated panels to the maximum extent practical. Joints are to be covered with suitable sealant or caulking. Unit equipment walls, roof, and floor shall be insulated with thermal insulation enclosed in panels and not exposed to air stream.

2.3.6. Condensate Drain: The evaporator shall be situated with the condensate pan, condensate drain and trap as high as practical to allow for collection of condensate in a collection tank/container.

The condensate drain piping is to be 1 – ¼” diameter schedule 40 pipe terminating with a 1 – ¼” male “Hanson” or equal type fitting. Also, the condensate trap is to be equipped with a plug to allow complete draining of the trap. The condensate drain piping is to be routed inside the unit to the maximum extent possible (i.e. only the “Hanson” fitting should be external to the unit).

2.4. Heaters:

2.4.1. Conditioning of 100% of the outside air by heating shall be accomplished by electric heaters located in the conditioning air section. The heaters shall be installed as assembled and rigidly supported to prevent sagging and adverse movement.

2.4.2. The heaters shall be modulated using five stages to provide the minimum amount of heat necessary to satisfy the demand without exceeding a discharge temperature of 125°F.

2.5. Compressor:

2.5.1. Compressors shall be hermetic scroll type. The compressor shall be equipped with a slide valve for capacity control. An 80-mesh reinforced stainless steel screen (minimum) strainer shall be provided at the suction port of the compressor.

2.5.2. The compressor shall be equipped with a crankcase heater and shall operate on R-410A refrigerant.

2.5.3. The compressor shall be equipped with a liquid injection valve for protection of compressor motor overheating in low load conditions. The A/C unit liquid line solenoid valve is to be interlocked with the blower. If the blower stops for any reason, the liquid line solenoid valve will close, causing the refrigeration circuit to automatically “Pump Down” and stop the refrigerant compressor

2.5.4. Each bearing shall be pressure lubricated by the oil from the oil separator. Compressor casings shall be of a double casting structure designed with high strength inner ribs designed to minimize noise and to ensure rigidity.

2.5.5. The motor shall be semi-hermetic, three phase, refrigerant cooled type. Safety controls shall include a compressor high pressure cutout, manual reset delay low pressure cutout, and compressor anti recycle timer. Provide a three phase monitor to confirm proper phase rotation and shut down the unit on loss of phase.

2.5.6. The compressor electric motor shall be suction gas cooled. It must also have a voltage utilization range of +/-10% of the nameplate voltage. There shall be winding thermostats embedded between three motor windings to protect against excessive winding temperatures. However, since a semi-hermetic compressor is specified, manufacturer installed head temperature sensors may be used in lieu of winding thermostats to shut down the compressor in the event of overloading.

2.5.7. The compartment and door arrangement shall be situated and of ample size to allow removal of the compressor through a side or end door without moving any major component.

2.5.8. The compressor shall be equipped with extra heavy-duty feet and isolation mountings to withstand the shock of unit handing.

2.6. Compressor protection:

2.6.1. The unit shall automatically shutdown and illuminate the Control Panel “High Discharge Pressure” indicator light in the event the compressor discharge pressure becomes excessive. The light shall remain illuminated and the unit shall not restart until manually reset at the control panel.

2.6.2. The compressor shall be protected with a high-pressure cutout that requires manual resetting to restart the compressor. The compressor shall also be equipped with an internal relief valve to prevent damage at very high head pressures.

2.7. Evaporator:

2.7.1. The refrigerant evaporator shall be direct expansion copper tube, aluminum fin, and shall have

AHRI certified minimum capacity of 240,000 BTU/hour.

2.7.2. Circuit loading shall be one to two tons per circuit at design conditions and shall not drop below .4 tons per circuit for partial loading.

2.7.3. Air leaving the evaporator shall be 40° F with no frost build-up on coils.

2.8. Condenser:

2.8.1. Air cooled condenser coils shall be copper tube, aluminum fin and be AHRI certified for minimum

240,000 BTU/hour, tested to 500 psi with sub cooling section.

2.8.2. The condenser coils shall be protected from damage by ½” (min) expanded metal. The expanded metal is to be either painted or corrosion resistant material.

2.9. Expansion Valve(s) and Sight Glasses:

2.9.1. The expansion valves shall be quick response thermo-expansion type capable of maintaining control of super heat over a wide range and eliminating liquid flooding on startup.

2.9.2. Refrigerant line(s) shall be equipped with a suitable sight glass which will indicate if the system is low on refrigerant or liquid is flashing in the liquid line due to an excessive condensing temperature with moisture indicator.

2.10. Refrigerant (R410A) Filters:

2.10.1. The refrigeration circuit shall be equipped with full flow replaceable type refrigerant filters. The filters shall be contained in a standard commercial filter canister equipped with a flange. The refrigeration circuit shall be equipped with filter bypass piping and valves to allow filter change outs without the loss of refrigerant during operation.

2.11. Piping:

2.11.1. Piping shall conform to American National Standard Institute (ANSI) 1331.5.

2.11.2. Soft solder, 50/50, 95/5, or Stay-Brite, for refrigerate piping shall be prohibited. Only silver solder with a minimum of 15% silver shall be used. All silver solder joints for refrigerant piping shall be made up (soldered) with a 100% nitrogen purge in the involved (heated) tubing, piping and fittings.

2.11.3. All refrigerant piping, from the evaporator to the compressor, and any exposed condensate piping inside A/C unit must be insulated with suitable foam type insulation (Armaflex or equal) of minimum 1” thickness. Insulation is to be glued or cemented to the piping and all joints are to be covered with suitable rubberized tape specifically manufactured for this purpose. Cooling mode operation of unit in humid outdoor air (70°F dew point) is to result in no condensation on piping or insulation.

2.11.4. The refrigerant circuit shall be equipped with valves of the “King” type or equal to control pump down and/or isolation of major system components without losing the refrigerant charge.

SECTION 3 – INSTRUMENTATION AND CONTROLS REQUIREMENTS

3. INSTRUMENTATION AND CONTROLS REQUIREMENTS:

3.1. General Instrumentation and Controls Requirements:

3.1.1. The control functions shall be designed and arranged to simplify the operator’s task in starting and stopping the unit and in selecting the conditioning modes of operation and also provide for failsafe operation.

3.1.2. All controls shall be positioned & mounted to provide adequate space for labeling.

3.2. Control panel:

3.2.1. The control panel shall be mounted at the front end of the unit enclosure and shall include the necessary gages, indicators and controls for opening and monitoring unit operation. The control panel and its component parts shall be weatherproof. Control panel shall incorporate a hinged door on the unit’s enclosure.

3.2.2. The door shall include a see-through window to permit viewing the control panel with the door closed. Any electrical connections exposed upon opening the hinged door shall be covered to prevent accidental contact by maintenance personnel.

3.2.3. Devices furnished on the control panel shall include, but are not necessarily limited to the following (all gages, meters, indicators, lighting and controls are to be identified with label plates):

Controls

Start – Stop (unit operation)

Air Flow Control (VFD)

Heat – Vent – Cool selector

On – Off (panel lights)

On – Off (interior lights)

Temperature Control (cooling, heating)

Ventilation unit interlock – “Interlock” or “Non-Interlock” switch

Gages and meters:

Airflow (CFM)

Differential Pressure across the Air Filters (inches w.g.)

Conditioned Air Temperature (at discharge air hood plenum, °F)

Hour meter

Refrigerant suction pressure

Refrigerant discharge pressure

Indicators and Lighting:

Ventilation – Blower “ON”

Cooling – “ON”

Heat – “ON”

Panel lights (for night operation)

Interior lights “ON” / ”OFF”

High Compressor Discharge Pressure (Red Light)

Ventilation Unit Interlock – “Interlock” or “Non-Interlock” position with annotation, “A/C UNIT WILL NOT OPERATE IN THE INTERLOCK POSITION UNLESS

INTERLOCK CIRCUIT IS COMPLETED (THROUGH A VENTILATION UNIT).

3.3. Air Flow Control:

3.3.1. Each Air Conditioning unit is to be equipped to control the conditioned airflow between 2,000 and

4,000 CFM at any output static pressure up to 16 inches of water gage via a Variable Frequency

Drive (VFD). Static discharge pressures are anticipated to normally be in excess of 10 inches of water gage. The air conditioning units are to have a control knob which controls the VFD. Flow is to be manually adjustable from 2,000 to max flow CFM using the VFD.

3.4. General Temperature Control:

3.4.1. The “COOLING”, “HEATING”, and “VENTILATION” modes are to be manually selected at the main control panel. Cooling and heating thermostatic controls are to be separate from each other.

The air quantity will be manually set (between 2,000 CFM and maximum flow rate) via the VFD.

3.5. Cooling Control:

3.5.1. Cooling control is to be accomplished utilizing conventional DDC control. The cooling control range for air leaving the evaporator is to be from 40º F to 90º F. The cooling control set point

(Main Cooling set point) is to be controlled by one adjustment. The Main Cooling set point is to have an adjustable control band from 2° F to 12º F or more.

3.5.2. There shall be a three-minute minimum and five-minute maximum delay between stages and four to five minutes recycle time delay. The cooling thermostat temperature probes are to be situated to sense the evaporator leaving air temperature (upstream of the cooling coil) and thus control the air temperature leaving the evaporator. The units shall be equipped with high and low pressure cutouts, non-recycling pump down, and five-minute start/restart delay timer.

3.5.3. The cooling temperature control shall maintain air temperature leaving the evaporator within plus or minus 5°F of the main cooling set point for air entering the A/C unit above 55°F.

3.6. Heating control:

3.6.1. This thermostat is to control the air temperature leaving the A/C unit in heating mode. The thermostat is to control staged electric heat. There shall be five stages of heat.

3.7. Airflow Measurement:

3.7.1. The unit is to be equipped with an airflow measuring station with a readout (Magnehelic gage) situated in the unit’s control panel. The readout is to indicate flow in CFM and calibrated to read within plus or minus 3% of the actual airflow based on the average velocity. The range of the airflow meter is to be zero to approximately 5,000 CFM.

3.8. Hour Meter:

3.8.1. The unit shall be equipped with a totalizing type hourmeter. This shall be of the non-resetting type and shall have a minimum range of 0 to 100,000 hours in increments of one hour. The least significant digit on the meter readout shall be 0.1 hour. Lesser increments are not acceptable.

3.8.2. Upon reaching the maximum accumulative hours, the meter readout shall automatically revert to zero and continue to totalize time. The meter shall be designed to prevent the entrance of dust and moisture and shall be mounted to withstand shock and vibration generated by the equipment.

The meter shall be located as to be readily visible, but not subject to abuse relative to the operating environment of the equipment.

3.9. Ventilation Unit Interlock Connection:

3.9.1. The interlock is to provide a means to automatically shut down the A/C unit blower while the A/C unit is interlocked with a ventilation unit once the interlock circuit is opened (i.e. ventilation unit is shut down). When not externally connected to a ventilation unit, the A/C unit blower will only run when the ventilation unit interlock switch is in the “Non-Interlock” position. In the “Interlock” position, the A/C unit blower must not operate unless the interlock circuit is completed through an auxiliary contact on the applicable ventilation unit.

3.9.2. The unit is to have a two conductor connection in the form of a screw type weatherproof electric plug for remote lockout control. The female side of the plug is to be mounted on the A/C unit.

Both a weatherproof screw type cover and a mating male plug are to be provided with each A/C unit.

3.9.3. The ventilation unit interlock connection is to be identified with a weather proof label plate annotated, “Ventilation Unit Interlock Connection.”

SECTION 4 – ELECTRICAL REQUIREMENTS

4. ELECTRICAL REQUIREMENTS:

4.1. General Electrical Requirements:

4.1.1. All electrical components including motors, starters, relay, switches, thermostats, and wiring shall conform to and be located in accordance with applicable NEMA, ANSI and NFPA standards for the intended application. All electrical components shall be individually and clearly identified with permanent label plates.

4.2. Supply Power:

4.2.1. The A/C unit power supply will be 460 VAC, three phase. The maximum current shall be 150

Amps. The power connection will consist of three female Camlock type connectors (threaded stud style) mounted on the A/C unit. The color coding will be as follows: Black – phase “A”, White – phase “B” and Red – phase “C”. The following are the applicable connectors:

Series E1016-1626 (or equal) Black

Series E1016-1636 (or equal) White

Series E1016-1633 (or equal) Red

4.2.2. The electrical power connection shall be identified with a weatherproof label plate annotated “460

VAC = 3 Phase -- Amp Service.” The blank is to be filled in by the contractor as applicable.

4.2.3. The Camlock fittings used for NNSY temporary services are normally the type provided by the

Duraline Manufacturing Company to suit the applicable amperage. The electrical connectors are to be situated between 18” and 24” above ground level on the control panel end of the A/C unit.

4.3. Electrical Power Disconnect:

4.3.1. A supply circuit quick disconnect device, fusible motor circuit switch or circuit breaker, shall be provided and installed on the equipment.

4.4. Grounding Lug:

4.4.1. Each A/C unit must be equipped with a grounding stud. This shall be minimum ½” diameter copper supplied with a copper nut and suitable washer. The ground stud shall be identified with a weatherproof label plate annotated “Equipment Ground.”

4.5. Motors:

4.5.1. Motors shall be rated for continuous duty and shall be equipped with ball bearings. Bearings shall not be sealed and shall be equipped with grease fittings and spring loaded relief plugs to allow re-lubrication.

4.6. Control Circuits:

4.6.1. Main and auxiliary control circuits shall operate on a circuit of 115 volts or less derived from isolation transformer(s) integral with the equipment. Thermostatic control circuits shall be 30 VAC or less.

4.7. Electrical Connections:

4.7.1. All electrical connections within the equipment shall be complete and shall be made via terminals on the components, terminal/circuit boards and bussing. In no instance shall splicing of wiring between terminations be permitted in the construction nor the repair of the equipment.

Connections/terminals shall be adequately supported and spaced without dependence upon the wiring in the components and braced as necessary to assure withstanding the distortion forces associated with available short-circuit currents. Proper identification of wiring, bussing, terminals, and circuits for function, polarity, phasing, etc., shall be adhered to throughout the equipment.

4.7.2. Identification shall be in the form of wire markers, color coding, permanently engraved plates, and permanent markings on the devices. Adequate spacing shall be maintained throughout to avoid excessive banding of cabling and wiring, to maintain adequate separation and creepage distances between electrical potentials, and between these potentials and ground, and to permit ease in connection and disconnecting wiring and cabling during trouble-shooting and repair. In no instance shall clearances and creepage distances be less than those prescribed under NEMA

ICS, Part ICS 1-111.

4.8. Grounding:

4.8.1. All exposed, non-current carrying metal parts on the equipment shall be maintained at common zero ground potential. None of the primary circuits in the equipment shall be connected to ground.

A ground stud or lug on the equipment shall provide the means for grounding the equipment for safety to personnel. One-half inch copper 13UNC minimum 1” long painted green and labeled ground.

4.9. Solid State Components:

4.9.1. The use of solid state components is to be minimized to the maximum extent practical.

Conventional electrical controls are to be used wherever practical.

4.9.2. The use of selenium and other similar aging devices shall be permitted only in the application of voltage surge protection to the other solid-state components.

4.9.3. When solid state devices are used, each device shall be selected and installed to have characteristics and withstand ratings compatible with its intended function and application in assuring long life and reliability. Solid-state components shall not be adversely affected when subjected to radiated and conducted type heat resulting from an industrial environment. Series and parallel connections of solid-state devices without forced sharing circuitry for voltage and current respectively shall not be permitted.

4.10. Guards:

4.10.1. Protective guards shall be placed over electrical components / connections as necessary to prevent damage.

4.11. Enclosure (Power and Ground Monitoring Panel):

4.11.1. Unit must utilize a power and ground monitoring system. The purpose of this system is to read incoming power in volts (phase-to-phase and phase-to-ground). The A/C unit power is alternating current (AC). The supply voltage is typically 460 volts AC (VAC). The origin of the supply power is typically from a standard 480 VAC grid system, minus line drop, allowing typical voltage readings at the equipment of approximately 460 VAC.

4.11.2. The “Power and Ground Monitoring Panel Enclosure” must be recessed into the aluminum enclosure of the A/C unit. The enclosure must be constructed of aluminum and must have an aluminum framed safety glass door. The area of the glass must be equal to or greater than 80% of the square area of the door, this to allow the meter to be easily seen without opening the door.

The door must have an aluminum continuous hinge located at the bottom and an aluminum latching device at the top. There must be a braided ground strap attached across the hinge to ensure the equipment ground of the door is not dependent upon the hinge-pin alone.

4.11.3. The door must swing a minimum 180 degrees and rest against the vertical plane of the A/C enclosure. The door must be weatherproof with a gasket to seat the entire perimeter of the door.

The door, when closed, must be flush with the outside vertical plane of the A/C enclosure. The enclosure must allow easy access and must be large enough to allow unrestricted access to the meter and selector switch handle and allow markings to clearly indicate the name and positions of the selector switch: “Selector Switch”, “Phase-to-Phase, (“A”, “B”, “C”); Phase-to-ground”, (“A”, “B”, “C”). The panel must be large enough to allow markings to clearly indicate the “Volt Meter” and its “Range” “0 thru 500 volts”.

4.11.4. There must be adequate room to allow the switch to be rotated without the hand or the selector switch handle obscuring the face of the meter. The Power and Ground Monitoring Panel enclosure must be easily accessed from the outside of the A/C unit enclosure.

4.11.5. Selector Switch: The selector switch must be rated heavy-duty, industrial grade. It must be a six-position (minimum) switch with all unused positions marked as "OFF". The handle of the switch must be readily accessible, non-conductive, and of sufficient size to be easily operated by a man with his hand in a 10,000-volt rubber glove and that glove covered by a leather protective glove.

4.11.6. Meter (digital): The digital meter must be heavy-duty, industrial grade, digital. Each number of the display must be at least 0.375-inch in height. The meter must indicate volts AC. The range of the meter must be from 0 (zero) to 500 (five hundred) volts AC and read to the nearest volt.

Note: decimal portions of a volt are not required, but will be acceptable, provided the whole number of volts is also indicated. The meter must be readily accessible and easily seen with the door open or closed. The meter must have no exposed electrical points of contact.

4.11.7. Testing: Testing and certification of the Power and Ground Monitoring Panel Meter's ability to display the true applied voltage is required. The use of a calibrated meter connected to the source test voltage and verification of the same reading on the panel meter is the minimum acceptable test and certification. Tests must be conducted in each switch position and must include both extremes of the meter. At least eight (8) other intermediate voltages, near or equally spanning the full meter range is also required. Meg-Ohm Meter (Megger) checks of all conductors, after installation and prior to hook-up, is required.

4.12. Current Transformer:

4.12.1. Current transformers (CT) must be securely mounted to ensure they do not move during transport and during normal use of the A/C units. Vibration dampening and chafing material is left to the discretion of the builder. Note: responsibility to ensure no chaffing of any conductors, wiring, wiring harnesses, or components is the sole responsibility of the builder. Any evidence of compromise of conductors, wiring, wiring harnesses, or any components will be grounds for rejection by the government.

4.13. Wiring:

4.13.1. The wiring must be stranded copper. The insulation must meet or exceed Thermoplastic High

Heat-Resistant Nylon-Coated (THHN), Thermoplastic Heat and Water-Resistant Nylon-Coated

(THWN), and Machine Tool Wire (MTW). Special equipment wiring, supplied and warranted by the manufacture of the equipment, is considered acceptable under this specification. The wiring must be rated for the applied voltage and must be capable of carrying the maximum current flow designed for that circuit. The wiring must be routed and supported to protect the conductors from physical damage. The conductors must be color-coded or numbered to ensure ease of troubleshooting. Shielding of conductors to prevent inductive error that will affect the readings of the meter is required.

SECTION 5 – STRUCTURAL REQUIREMENTS

5. STRUCTURAL REQUIREMENTS

5.1. Structural base:

5.1.1. The component parts of the air conditioner shall be properly assembled on a rigid structural aluminum skid base of uniform space dimensions with aluminum frame of heavy gage aluminum channel that is welded, gusseted, and cross-braced as necessary to support the equipment and to withstand the stresses, vibration and shock associated with the rough handling and transport of the complete air conditioning unit by forklift truck and overhead crane in dockside applications.

5.1.2. The design and arrangement of components shall provide ready access to all parts of the equipment to facilitate inspection, maintenance and repair. No component part shall extend outside the perimeter of the skid base except for the condensate pipe, intake and supply duct fittings and power connections.

5.1.3. The unit is to be as compact as practicable but should be no wider than 10 feet. The maximum size shall not exceed 15 feet long x 10 feet wide x 10 feet high (not including the intake plenum which is to be located on the opposite end of the unit from the controls) unless otherwise approved in writing by NNSY.

5.2. Crane Handling:

5.2.1. The air conditioning units shall be equipped with lifting pads attached to the top to accommodate a four (4) point lift. Each lifting pad shall be designed to lift one half (1/2) of the total weight of the air conditioning unit with a design factor of 5 to 1 based on ultimate strength. The lifting pads shall be aluminum.

5.2.2. Each lifting attachment shall be designed to accept a standard anchor shackle (Federal Spec RR-

C-271G, Type IVA). Lifting pads shall be such that the attachments and shackles are not side loaded more than 10° out of the plane of attachment to ensure safe handling and transportation by an overhead crane. The unit, when suspended, shall hang as level as possible with the horizontal.

5.2.3. The four lifting pads must pass a Magnetic Particle (MT) Inspection per MIL-STD-271 with acceptance to MIL-STD-2035A for class 3 welds. The contractor shall provide NNSY with the design calculations and NDT results for the lifting pads.

5.2.4. The gross weight of the unit must be stenciled on all four sides of the unit with minimum two-inch high letters that contrast with the unit coating.

5.3. Forklift Handling:

5.3.1. The air conditioning units shall be equipped with box section tine guide openings in the base for safe handling and transport by forklift truck. The center of gravity of the air conditioning units must be relatively centered between the tine guide openings. The box sections shall extend through the entire length or width of the equipment completely enclosing the forklift tine and shall be fabricated from aluminum having a minimum thickness of ¼ inch.

5.3.2. The box sections shall have inside cross-sectional dimensions of at least 10 inches wide x 5-1/2 inches high. They shall be welded to the base and spaced apart center to center so that a forklift truck, while transporting the equipment, can pass over pavement obstructions causing dynamic

SECTION 5 – STRUCTURAL REQUIREMENTS

stresses representing five times the equipment’s weight without causing the box sections to fracture or part from the base.

5.3.3. The box sections shall be 42 inches apart (center to center) and the full width of the unit. All panel operators, door operators and the condensate drain line shall be located to preclude damage during forklift handling.

5.4. Enclosures:

5.4.1. The air conditioner shall be contained in a housing of a minimum 12 gage aluminum sheeting and welded structural aluminum frame with solid metal floor of sufficient rigidity to withstand rough handling. The floor is to be aluminum plate of at least 1/8” thickness.

5.4.2. Interior lights, switched from control panel, shall provide adequate illumination for personnel to safely perform routine maintenance and inspections in the unit during night operation. The interior lights shall be vapor-proof incandescent marine style lights.

5.4.3. Door or access panel handles are to be recessed flush with the access door or access panel.

Doors and access panels shall have a “rain guard” installed to prevent leakage into the opening and shall have a latch or similar device to secure in the open position.

5.5. Intake and Discharge:

5.5.1. The intake duct connection shall accommodate flexduct of a standard size, minimum diameter

14”. The flexible duct connection outside diameter (OD) shall be a nominal ½” less than design flexduct diameter (e.g. 13 ½” OD for 14” diameter flexduct). The flexible duct connection must be at least 8” long. Connection must be smooth, with no holes or clamping mechanisms along its length.

5.5.2. The discharge duct connection shall accommodate flexduct of a standard size, minimum diameter

14”. The flexible duct connection outside diameter (OD) shall be a nominal ½” less than design flexduct diameter (e.g. 13 ½” OD for 14” diameter flexduct). The flexible duct connection must be at least 8” long. Connection must be smooth, with no holes or clamping mechanisms along its length.

5.5.3. The intake and discharge duct connection shall be designed to minimize friction / turbulence losses.

5.5.4. The area around intake and discharge duct connections shall be unobstructed within at least 6 inches in all directions, to permit bagging of unit openings when unit is not in use.

SECTION 6 – GENERAL CONSTRUCTION REQUIREMENTS

6. GENERAL CONSTRUCTION REQUIREMENTS:

6.1. Label plates:

6.1.1. All label plates (interior and exterior) are to be curable weatherproof plastic or photo-engraved aluminum. All are to be attached with screws or nuts (glued label plates have a tendency to fall off).

6.2. Fastening devices:

6.2.1. All screws, pins, bolts and similar internal and external parts shall be installed with means for preventing change of tightness (e.g. locknuts, lock washers, lock tabs, etc.). Such parts subject to removal or adjustment shall not be swaged, peened, staked, or otherwise permanently installed.

All fastening devices shall be tightened to torque limits as established by the manufacturer’s standard for tightening to preclude loosening by normal operation or vibration.

6.3. Surfaces:

6.3.1. All surfaces of castings, forgings, molded parts, stampings and welded parts shall be cleaned and free from sand, dirt, fins, sprues, flux or other harmful or extraneous materials. External surfaces shall be smooth, and all edges shall be either rounded or beveled unless sharpness is required to perform a function.

6.4. Brazing:

6.4.1. All brazing shall comply with NAVSHIPS Instruction 250-634-6. Brazing shall also comply with

MIL-B-15395. For CU or BRS joints, use Grade III alloy BcuP-5. For CU or BRS to steel joints use

Grade IV alloy BAG-1a.

6.5. Materials:

6.5.1. No lead or mercury may be used in any part of the unit or the instrumentation without prior written approval by NNSY.

6.6. Dissimilar Metals:

6.6.1. Dissimilar metals shall not be used in direct contact with each other without suitable means for preventing electrolytic corrosion.

6.7. Weatherproofing:

6.7.1. The unit shall be enclosed and suitable for use in a seashore environment where dust, dirt, and salt-laden, moist air are prevalent. The portable high pressure air conditioning units will operate in a shipyard environment exposed to rain, snow, and windblown dust. The outdoor ambient temperatures are expected to be between 20º F to 100º F with relative humidity ranging between

30% and 100%.

6.8. Maintainability:

6.8.1. The equipment shall be designed and constructed to permit maintenance personnel to easily and effectively service the equipment using a minimal number of tools. The units shall be equipped with access doors to facilitate inspection, cleaning, and repair or replacement of parts. Consistent with required maintenance and design of Air Conditioning Units, the contractor shall provide any special tools required to service the unit. The contractor shall also provide a recommended spare parts list with the Air Conditioning units.

6.9. Interchangeability:

6.9.1. All replaceable parts shall be manufactured to industry standards, tolerances and clearances so that replacement parts are able to be installed without requiring modification of the Air

Conditioning units.

6.10. Safety:

6.10.1. Each air conditioning unit shall be manufactured from standard, commercially available new components and shall meet the following safety and health requirements.

6.10.2. Covers, guards or other safety devices shall be provided for all parts of all equipment that present safety hazards. The guards shall be made of a minimum 16-gauge aluminum sheeting. The safety devices shall not interfere with operation of the equipment. The safety devices shall prevent unintentional contact with the guarded part, and shall be removable to facilitate inspection, maintenance, and repair of the parts. All machine parts, components, mechanisms, and assemblies furnished on the unit shall comply with all specific requirements of “OSHA Safety and Health Standards (29CFR1910) General Industry” that are applicable to the equipment itself.

6.10.3. Audible noise emitted by the air conditioning units shall not exceed 84 dB at the operator’s work position or at any other point at a distance of three feet from the equipment under all operating conditions, as measured on the “A” weighted scale of a standard sound level meter.

6.11. Additional Specifications:

6.11.1. Sheet metal, structural steel, components, parts, pipe, fittings, electrical and mechanical material, and test methods or ratings must comply with the specifications of Table 1 below.

TABLE 1 – SPECIFICATIONS FOR CONSTRUCTION OF 20-TON AC UNITS

ITEM DESCRIPTION

APPLICABLE

SPECIFICATIONS /

PUBLICATIONS

Filters, Air Conditioning ANSI/ASHRAE 52.1

Federal Specification

Flux Brazing (silver alloy, low melting point) O-F-499D

Brazing Alloys, Silver QQ-B-654A AM1

Traps and Vents (for steam, air and other applications)

A-A-60001A

Screw Thread Standards Federal Standard H28/20B

Fans, Venting, Propeller A-A-50032B

Strainers, sediment: Pipeline, Water, Air, Gas, Oil, or Steam

WW-S-2739

Fan, Centrifugal, Ventilation, Naval Shipboard MIL-PRF-19004B Military Specification Variable Speed Drive System for Induction and

Synchronous Machines

MIL-PRF-32168

Performance Rating of Liquid Line Driers

AHRI Standard 711 (SI)-2009

Air Conditioning and Refrigeration Institute (ARI) Publications

Laboratory Methods of Testing Air Circulating Fans for Rating and Certification

AMCA Standard 230-15 Air Movement Control Association (AMCA) Publications

Malleable Iron Threaded Fittings ASME B16.3-2011

American National Standards Institute (ANSI) Publications

Pipe Flanges and Flanged Fittings: NPS ½ Through NPS 24 Metric/Inch Standard

ASME B16.5-2013

Factory Made Wrought Buttwelding Fittings ASME B16.9-2010

Forged Fittings, Socket Welding and Threaded ASME B16.11-2011

Wrought Copper and Copper Alloy Solder Joint Pressure Fittings

ASME B16.22-2013

Cast Copper Alloy Solder Joint Drainage Fittings –

DWV

ASME B16.23-2011

Refrigeration Piping and Heat Transfer Components

ASME B31.5-2010

Pressure Gauges and Gauge Attachments ASME B40.100-2013

Malleable Iron Threaded Pipe Unions: Classes 150, 250, and 300

ASME B16.39-2014

Valves Flanged, Threaded and Welding End ASME B16.34-2013

Safety Code for Mechanical Refrigeration 15d-2000 American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) Publications

ASHRAE HVAC Systems and Equipment Handbook

Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless

ATSM A53/A53M-12

American Society for Testing, and Materials (ASTM) Publications

Steel Sheet, Zinc Coated (Galvanized) by the Hot Dip Process

ASTM A653/A653M-15

Seamless Copper Tube for Air Conditioning and Refrgeration Field Service

ASTM B280-13

Copper Drainage Tube (DWV) ASTM B306-13

Determination of the Thermal Resistance of Low- Density Blanket-Type Mineral Fiber Insulation

ASTM C653-97 (2012)

Surface Burning Characteristics of Building Materials

ASTM E84-15b

Pipe Hanger and Supports Selection and Application

MSS SP-69 Manufacturers Standardization Society of the Valve and Fittings Industry (MSS) Publications

Bronze Gate, Globe, Angle, and Check Valves

MSS SP-80

National Electric Code NFPA 70 National Fire Protection Association (NFPA) Publications Air Conditioning and Ventilating Systems NFPA 90A

HVAC Duct Construction Standards Metal and Flexible

Sheet Metal and Air Conditioning Contractors National Association (SMACNA) Publications

Factory Made Air Duct Materials and Air Duct Connections

UL 181

Underwriters Laboratories, Inc. (UL) Publications

Temperature-Indicating and Regulating Equipment

UL 873

Filters, Air Conditioning UL 900

SECTION 7 – DELIVERABLES

7. DELIVERABLES:

In addition to Air Conditioning units meeting the specifications of Sections 1-6 above, the following deliverables are to be included as part of this contract.

7.1. Preliminary Report:

7.1.1. Prior to fabrication of the 4000 CFM 20 Ton Air Conditioning units, the contractor is to review the included specifications. If required, submit a written report to the contracting officer indicating any deficiencies and/or desired deviations in the system specifications that would preclude proper fabrication of the specified Air Conditioning units.

7.2. Drawings:

7.2.1. Within 30 working days after contract award, the successful bidder will submit a complete set of drawings (including all structural, mechanical (showing all piping), and electrical (showing all power and automatic control circuits)) and complete list of materials with material specifications to

NNSY for review and approval. The material / components used are to be those listed in the bid under “Specifications” (section 2) unless the contractor has first obtained NNSY’s written permission to substitute specific items. No material procurement or manufacture of the air conditioning units is to commence until after the plans and associated bill of materials are approved in writing by NNSY. NNSY will review and approve or disapprove the drawings and list of material within 20 working days after receipt at NNSY.

7.2.2. All final drawings shall be composed using AutoCAD (2016 edition or earlier) in order to be compatible with current NNSY software. The contractor shall submit hard and electronic copies of these drawings. Hard copies shall be a minimum of C size (16” Wide x 21” High) with fully dimensioned layouts of skid structure, equipment, etc. All drawings shall indicate adequate clearance for operation, maintenance, and replacement of operating equipment services. Final approved assembly drawings shall be submitted to NNSY in the form of AutoCAD (2016 edition or earlier) disk with two hard copies.

7.2.3. Drawings and schematics must represent the "as built" system. These drawings and schematics must be developed and printed in a manner that is conducive to ease of use and understanding while troubleshooting.

7.3. Structural Objective Quality Evidence (OQE):

7.3.1. Documentation must be provided to demonstrate the structural integrity of the Air Conditioning units. This is to include Finite Element Analysis (FEA), and Non-Destructive Testing (NDT) of lifting pads, and load test per Paragraph 5.2.

7.4. Manuals:

7.4.1. Each unit is to be provided with two sets of operation and maintenance manuals, drawings and replacement parts list. This will include the respective manufacturer’s descriptive literature of cataloged products, equipment drawings, diagrams and performance curves. Installation, operation and maintenance manuals for all equipment shall also be submitted.

SECTION 7 – DELIVERABLES

7.5. Site Visit & Performance Test:

7.5.1. The Air Conditioning Units are to be performance tested by the contractor and witnessed by a

NNSY representative from the cognizant technical organization prior to shipment from the contractor’s plant. This contract is to support funding for travel expenses and accommodations for

NNSY representative to witness performance testing at the contractor’s plant.

7.5.2. A copy of the performance test for each unit is to be provided with each unit. There shall be a test result data sheet for each test required by these specifications. Each sheet shall indicate the specific unit, the date, the actual test results obtained, and the name and signature of the person who performed the test(s). The units are to be under warranty for a period of one year

(compressor for five years) or the standard commercial warranty, whichever is longer, from the date of physical receipt at NNSY, Portsmouth, Virginia.

7.6. Certificate of Compliance:

7.6.1. Final acceptance inspection is to be performed at NNSY. Manufacturer shall provide a Certificate of Compliance.

7.7. Training:

7.7.1. The contractor shall provide training/instruction concerning the operation, maintenance, trouble shooting and repair of the air conditioning units. The training shall cover all modes of operation.

Instruction shall only be provided by a manufacturer factory representative who is thoroughly familiar with the air conditioning units provided.