]2.1.9
Space Temperature Control System
[Provide microprocessor control system integral with unit including
electronic control center, control valves, sensors, wiring, and other
appurtenances for workable system. Provide access panel or door in front
of unit.
Isolate electronic control center from conditioned airstream to allow
service while system is in operation. Provide control sensors in unit for
cooling, dehumidifying, and humidifying. High-voltage circuits in system
shall have individual leg overload protection. Starters, contactors, and
relays shall be controlled by 24 volt control circuit.
High-voltage circuit components shall be protected by safety lock,
dead-front panel. Mount nonautomatic, molded-case circuit breaker in
high-voltage section of electrical panel. Operating mechanism shall
prevent access to high-voltage electrical components until switched to
"OFF" position.]
[Include the following control capabilities:
[a.
Capable of changing the set points and sensitivity of the space
and humidity along with their low and high alarm points.]
[b.
Logging capability of the last 10 alarms and run time.]
[c.
Diagnostics]
[d.
Refrigerant compressor sequencing]]
[Provide controls under Section 15901N SPACE TEMPERATURE CONTROL SYSTEMS.]
[Provide controls under Section 15910N DIRECT DIGITAL CONTROL
SYSTEMS.][Provide a controls interface on CRACU to enable the DDC system to
monitor the following operating parameters and alarm conditions: high and
low computer room temperature, relative humidity, CRACU status, [_____].]
2.1.10
Alarm Panel System
Provide unit with cabinet-mounted alarm panel which shall monitor high and
low space temperature, high and low space humidity, dirty filters, loss of
airflow, [ loss of [water][or glycol] flow,] compressor high head pressure,
and humidifier problems. Provide underfloor water detector. Provide field
accessible local audible alarm with silence pushbutton. Provide
push-to-test lamps or all-lamp test pushbutton. [CRACUs shall have local
devices which provide signals for remote audible and visual alarming
capability for the above specified alarm conditions.]
2.1.11
Air Return and Delivery Orientation
**************************************************************************
NOTE: Select one of the following two paragraphs to
specify air delivery and air return orientation.
Indicate the extent of the acoustical lining in the
downflow discharge duct.
**************************************************************************
[Computer room air conditioning unit[s] shall be downflow discharge, top
return, draw-thru cooling coil, and shall discharge air [into a raised
SECTION 15702N
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