SHELF UNIT - GUIDE SPECIFICATIONS
2, 3, and 4 ton
GENERAL
Provide and install a split type air conditioning system designed specifically for use in smallcomputer or electronic equipment areas. The unit shall be capable of cooling, humidifying,
dehumidifying and filtering air. Provide quantities and system configurations as shown on the
project drawings. Units shall be ETL listed.
CONTROLS
Precise temperature regulation shall be provided by a built-in control system. All electrical
components, including capacitors, contactors, relays and control transformers shall be pre-wired
and contained in an electrical box. A factory installed micro-switch will disable the unit prior to
condensate pan overflow should the drain become plugged with debris.
CABINET and FRAME
The frame shall be constructed of 14 gauge welded tubular steel and coated with a heavy
corrosion inhibiting finish. The outer steel casing shall have removable panels for servicing. The
panels shall be insulated with ½” inch thick, closed cell insulation for quiet and efficient operation.
An integral unit filter section with a 20" x 25" x 4" pleated filter shall be provided. The filters shall
be 30% efficient (based on A.S.H.R.A.E. Std. 52.1-1992).
WATER COOLED SYSTEMS
Provide a self-contained water cooled unit.
The cabinet shall house the evaporator section, evaporator blower assembly and filter section.
Evaporator coil shall be constructed with copper tubes and aluminum fins and mounted in a
stainless steel drain pan. The single refrigeration circuit shall include a scroll compressor with
internal protection and crankcase heater. The refrigeration circuit shall include an expansion
valve with external equalizer, filter drier, sight-glass and high and low pressure safety switches. In
addition, a high efficiency plate-fin condenser with head pressure activated 2-way water
regulating valve shall be built into the refrigeration system and contained in the evaporator
section. The blower assembly shall be a draw-through type with a centrifugal, forward curved,
double width, and double inlet blower configuration engineered for quiet, reliable operation. The
belt driven variable pitch drive shall provide adjustable air flow capability to match the
requirements of the controlled space. The draw-through design shall insure even air distribution
across the coil, low internal cabinet losses, and static sealing of the filter section. The evaporator
motor shall have internal overload protection and shall be mounted on an adjustable slide base.
Note: A fluid cooler or water cooling source is required.
OPTIONS
MINI DATA ALARM PROCESSOR-II™
Provide a Mini Data Alarm Processor-II. The microprocessor shall be a wall mounted and, one
row, 16-character control that will monitor the controlled environment’s humidity, air flow and
cleanliness, but also provides alarm history and an automatic self-test of the microprocessor on
system start-up. Multiple messages shall be displayed by automatically scrolling from each
message to the next. All messages shall be presented in a clear vernacular format on the liquid
crystal display (LCD). Multiple alarms shall be displayed sequentially in order of occurrence.
OPERATION - A slide switch shall allow unit on/off operation. Push buttons shall allow menu
selection for programming, operational information, diagnostics and historical data. The two-level
password feature shall prevent unauthorized access. Menu programmed information for basic
system operation and alarm parameters shall be non-volatile.
PROGRAMMABLE FUNCTIONS - The user friendly MENU and SELECT push buttons shall
permit step-by-step programming of the following selections:
• Temperature setpoint: 60-80° F/18.3-29.4° C
• Temperature deadband: ± 1-5° F/C
• Temperature alarm points
• Calibrate temperature sensor
• Unit start time delay
• Password - 1st level
• Audio alarm level
• Firestat trip temperature
• Humidity setpoint: 30-70% RH
• Humidity deadband: ± 1-15% RH
• Humidity alarm points
• Calibrate humidity sensor
• Interstage time delay
• Password 2nd - level
• Restart mode
• Local alarm
DISPLAYED CONDITIONS, DATA, and FUNCTIONS - The Mini Data Alarm Processor-II shall
display and monitor the following conditions, data, and functions:
• Temperature setpoints
• Current temperature
• Cooling
• Humidification
• Date and time
• Humidity setpoint
• Current humidity
• Reheat
• Dehumidification
• Occupied/unoccupied period
ALARMS - Alarm conditions shall be displayed and monitored on the microprocessor LCD along
with an audible alarm. The alarm silence switch shall quiet the audible alarm but the display shall
continue to indicate the alarm condition until it is corrected. The following alarms shall be capable
displaying:
• High temperature warning
• Low temperature warning
• No air flow
• Power failure restart
• Low voltage warning
• Humidity sensor error
• Change filter*
• No water flow*
• Smoke alarm*
• Local alarm 1*
• High pressure compressor 1*
• High humidity warning
• Low humidity warning
• Firestat tripped
• Compressor short cycle
• Temperature sensor error
• Condensate pan high level
• Humidifier failure*
• Fan overload*
• Low pressure 1*
• Local alarm 2*
HISTORICAL DATA - Temperature and humidity, with the minimum and maximum readings
since the last power on shall be recalled and displayed. Alarm history shall be maintained in
sequential order (last 5 alarms).
DIAGNOSTICS - Automatic and manual diagnostics shall simplify troubleshooting.
In addition, the Mini Data Alarm Processor-II shall have an inclusive seven-day programming
format for unoccupied or low demand periods. This secondary schedule shall minimize equipment
runtimes, reducing energy consumption and provide user cost savings.
The following selections shall be adjusted to match the requirements needed for the unoccupied
or low demand periods:
• Cooling Setpoint for Secondary Schedule
Adjustment range: 1-30° F above the "occupied" temperature setpoint
• Reheat Setpoint for Secondary Schedule
Adjustment range: 1-30° F below the "occupied" temperature setpoint
• Dehumidification Setpoint for Secondary Schedule
Adjustment range: 1-30% RH above the "occupied" humidity setpoint
• Humidification Setpoint for Secondary Schedule
Adjustment range: 1-30% RH below the "occupied" humidity setpoint
• Day Schedule
Scheduling for each day of the week or any combination of days
• "Unoccupied" Adjusted Setpoint Operation
Adjusts to temperature and humidity setpoints to secondary schedule
• "Unoccupied" ON/OFF Operation During "unoccupied" schedule
Cooling: off
Heating: off
Humidification: off
Dehumidification: off
Fan: off
• Override Request (Overrides Secondary Schedule)
Adjustment range: 1-12 hours
*Alarm displays require additional components or sensors and programmable selections. Some
alarm messages are selected in three optional alarm menus.
STEAM GENERATOR HUMIDIFIER - Provide an electric steam generator humidifier with
disposable cylinder and self-regulating auto flush. Units with steam generator humidifier shall
require the Mini Data Alarm Processor-II.
DISCONNECT SWITCH - Provide a unit mounted disconnect switch with 1/4 turn latch. The
switch must be in the "OFF" position to remove panel and access electrical compartment.
EXTENDED COMPRESSOR WARRANTY - Provide an additional two-year or four-year
extended compressor warranty.