Appendix_G_-_CRAH_Specification.pdf

DISA MPE Facilities Engineering

Team April 2017

MINIMUM TECHNICAL

SPECIFICATIONS FOR

COMPUTER ROOM AIR HANDLING (CRAH)

EQUIPMENT

1. SCOPE.

Scope: This specification covers the technical requirements for a Computer Room Air Handler (CRAH) that provides precision environmental control (including temperature, humidity (if requested as an option), and air volume) supporting IT equipment rooms.

2. APPLICABLE STANDARDS.

The CRAH will be designed, manufactured, tested, and installed in compliance with the following standards:

• National Electric Code (NEC) Code 70

• Underwriters Laboratory (UL) Listed in accordance with UL 478, Standard for Electronic

Data Processing Units and Systems, at date of manufacture.

• Fully CSA (NTRL-C) ASHRAE 90, IEEE certified at date of manufacture.

3. REQUIREMENTS.

3.1 Design Requirements - The unit shall be sized for cooling capacities similar to either CW106D with a minimum sensible capacity of 335 kBTUH or CW146D with a minimum sensible capacity of 470 kBTUH specified by the PWS.

3.1.1 Electrical Requirements.

3.1.2 Input - The input voltage to the PDU will be 460-480V AC at 60hz, three phase.

3.1.3 High Voltage Enclosure - The unit shall have a safety locked dead front panel to prevent accidental contact with high voltage components. The high voltage panel shall contain all of the contactors, transformers, overloads, ground bars, and other power gear.

3.1.4 Main Disconnect Switch - The CRAH will be equipped with a main front-panel mounted disconnect switch to provide a means of disconnecting power to the CRAH. This disconnect will be non-locking (the front panel can be opened without the switch being in the OFF position).

3.1.5 Provide an in-unit dual fed automatic transfer switch to accept two power sources to power the unit. However, only one source will be provided per the scope. The second source will be provided in the future under an entirely separate contract from this one.

3.1.6 Premium efficiency motors

3.1.7 65 kAIC Short Circuit Current Rating

3.2 System Type Requirements.

3.2.1 DISA employs chilled water at its data processing sites to provide cooling. The CRAH unit shall be designed to cool on conditioned chilled water supplied at 44 deg. F Chilled Water

3.3 System Discharge - DISA computer rooms are built on raised access computer floors designed for underfloor plenum cooling. Downdraft units are specified for use in these facilities unless special conditions otherwise exist

Downflow Updraft Bottom Front Other (Specified Elsewhere)

3.4 Cabinet and Frame - The exterior shall be powder-coated steel panels with minimum 1”, 1-1/2 pound density insulation on the interior for sound baffling. The cabinet shall be constructed of minimum 14 gauge welded tubular steel for seismic resistance. The maximum system height is typically 84”, but may be lower in some older computer rooms (Dayton and Chambersburg).

Doors and side panels are finished in Black Cream White

3.5 Fans – Air Volume minimum = 17,000 CFM at 0.2 inch ESP. The fans are plug/plenum type, single inlet and shall be dynamically balanced. The drive package shall be direct drive, electronically commutated and variable speed. The fans shall be located to draw air over the A-frame coil to ensure even air distribution and maximum coil performance. The motor shall be premium efficiency. The shaft shall be heavy-duty steel with self-aligning ball bearings with a minimum life span of 200,000 hours.

3.6 Humidifiers - Humidifiers are not specified. DISA intends to use a humidification system independent of the CRAH units in its data center facilities.

3.7 Reheat - Reheat shall be used to control temperature during dehumidification. The electric reheat coils shall be low watt density, 304/304 stainless steel fin tubular construction, protected by thermal safety switches, shall be controlled in three stages. The reheat elements shall be removable from the front of the cabinet

3.8 Filters - Filters shall be deep pleated 4" filters with an ASHRAE 52.2 MERV11 rating (60-65%

ASHRAE 52.1).

3.9 Coil - The unit shall employ an A-frame coil system to maximize face area, decrease necessary face velocity, and minimize pressure drop. The unit shall be equipped with a removable stainless steel corrosion-free condensate catch pan.

3.10 Local Monitoring - The CRAH will have a local graphic monitoring panel affixed to the unit and will be a microprocessor-based system that includes the following:

• Password control.

• System auto restart, with programmable time delay.

• Sequential load activation.

• Sensor calibration.

• Monitoring – current temperature and humidity, current alarms.

• Sensitivity - responds to +/- 0.1 degree F temperature and +/- 1% relative humidity.

• Diagnostics on control board, fan, chilled water valve, alarm.

• Alarm log history.

• Run time log.

• Audible and visual alarm.

• Alarm conditions – change filter, loss of air flow, hi temp, low temp, hi humidity, low humidity, main fan overload, loss of power, loss of water flow., compressor overload, smoke sensor

• Modbus / BACnet Communication

3.11 EC Fan Motors – Electronically Commutated (EC) Direct Drive Fans with Variable speed control.

3.12 Floor Stand -The unit shall be mounted level with the top of the raised floor on an adjustable seismic- rated floor stand designed for the equipment.

3.13 Turning Vane - If the CRAH units are downflow, provide and install a field-mounted turning vane system to mount to the floor stand. The typical raised floor height in DISA facilities is 18-24”. Coordinate with the site Facility Manager for exact height and underfloor obstruction information after award of the contract.

3.14 Semi –Hermetic Compressor - The compressor shall be semi-hermetic with a suction gas cooled motor, vibration isolators, thermal overloads, oil sight glass, automatic reset high pressure switch with control lockout after three failures, pump-down low pressure transducer, suction line strainer, service valves, reversible oil pumps for forced feed lubrication, a maximum operating speed of 1750 RPM. The system shall include cylinder unloaders on the semi-hermetic compressors. The unloaders shall be activated by solenoid valves which are controlled from the microprocessor control. In response to the return air temperature, the microprocessor control shall activate the unloader solenoids and the liquid line solenoids such that four stages of refrigeration cooling are obtained. The stages shall be: 1) one compressor, partially loaded, 2) two compressors partially loaded, 3) one compressor partially loaded, one compressor fully loaded, 4) two compressors fully loaded. On a call for dehumidification, the microprocessor control shall insure that at least one compressor is on full for proper humidity control

3.15 Digital Scroll Compressor - The compressor shall be scroll-type with a variable capacity operation capability. Compressor solenoid valve shall unload the compressor and allow for variable capacity operation. The compressor shall be suction gas cooled motor, vibration isolators, thermal overloads, automatic reset high pressure switch with lockout after three failures, rotalock service valves, pump down low pressure transducer, suction line strainer, and a maximum operating speed of 3500 RPM. Consult factory for 575V availability.

3.16 Refrigerant - The system shall be designed for use with R-407C refrigerant or equal, which meets the EPA clean air act for phase-out of HCFC refrigerants.

3.17 Condensate Pump - The condensate pump shall have a minimum capacity of 145 GPH (548 l/h) at 20 ft. (58 kPa) head. It shall be complete with integral dual-float switches, pump-and-motor assembly and reservoir. The secondary float shall send a signal to the local alarm and shut down the unit upon high water condition.

3.18 Temperature and Humidity sensor location/s

Supply Return

3.19 Leak Detection system under the floor that encompasses the area of the unit and provides local alarming to the panel

3.20 Smoke Sensor with dry alarm contacts for remote alarming

3.21 Controls Requirements

3.21.1 Provide the appropriate communication card or hardware to support connecting the unit to the sites building automation system per the Controls Standards specified in the PWS.

4. INSTALLATION, TESTING & CERTIFICATION.

4.1 Factory Testing - The CRAH will be completely factory tested before shipment.

4.2 Delivery - Plywood or masonite panels shall be used when delivering and installing the unit(s) to distribute equipment weight and prevent damage to carpeting, ramps, and raised floor surfaces.

4.3 Installation - Install in accordance with manufacturer’s installation instructions. Install units plumb and level, firmly anchored in locations recommended, and maintain manufacturer’s recommended clearances.

Minimum standard clearances shall be 34” on the front and sides of the unit, unless the manufacturer’s recommendation is greater.

4.4 Electrical Wiring - Install and connect electrical devices furnished by manufacturer but not specified to be factory mounted. Furnish copy of manufacturer’s electrical connection diagram submittal to electrical contractor. Use di-electric unions when mating dissimilar metals.

4.5 Piping Connections - Install and connect devices furnished by manufacturer but not specified to be factory mounted. Furnish copy of manufacturer’s piping connection submittal to piping contractor.

4.5.1 System shall have a 2-way control valve in order to modulate the flow to the unit.

4.6 Water Circuit: Provide the installation and assembly shown in Figures 1 and 2. Include a circuit setter shown in Figure 1.

Figure 1

Circuit Setter

4.7 Each CRAH shall be piped to provide and return chilled water from either Loop A or Loop B at user’s digression. All four (4) pipes shall have isolation valves to be able to either perform maintenance or isolate to run on only one Loop.

4.7 Field Quality Control - Start up units in accordance with manufacturer’s start up instructions.

Test controls and demonstrate compliance with requirements.

4.8 Submittals - Submittals shall be provided to the site Facility Manager at installation and start up.

These shall include: Installation and Operations Manuals, Single-Line Diagrams, Dimensional- Electrical- Capacity Data, and Piping & Electrical Connection Diagrams.

5. SERVICE:

5.1 Startup, Maintenance, & Warranty - Inside delivery is specified on all orders. The manufacturer will provide one year of warranty against defects in materials and workmanship.

This warranty will provide startup, maintenance, and emergency call back to ensure dependable operation through the warranty period.

Figure 2