Specifications

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GUIDE SPECIFICATIONS 7-46 kW DX units
The following protocols shall be supported:
Modbus RTU, TCP/IP or ASCHII SNMP V1 or V2
BACnet IP or MS/TP LonTalk SNVT
Johnson Metasys (N2)
I. Building Management System Interface: Unit(s) shall be furnished with an interface card to communicate directly with
the Building Automation System (BAS) through a RS-485, Ethernet or LonTalk port. All alarms, set points, and operating param-
eters that are accessible from the unit mounted control panel shall also be made available through the BAS.
1.10 OPTIONS
A. Energy Saver Coil - The environmental control units shall be provided with an Energy Saver coil. The Energy Saver coil shall
be an integral part of the unit and will be capable of providing the total cooling capacity. Whenever the incoming water/glycol
temperature is below the setpoint of the water changeover thermostat, Energy Saver cooling shall be available.
The Energy Saver shall operate in the following range: Return air setpoint plus deadband plus 2 degrees.
The Energy Saver shall operate providing there is a need for cooling. The valve shall open at setpoint plus deadband. The valve
shall modulate as long as the space is between setpoint plus deadband plus 2 degrees. If the temperature falls below the deadband
minus setpoint, the valve shall close and the space shall be considered satisfi ed. While still in Energy Saver with the valve modu-
lating, if the temperature goes beyond setpoint plus deadband plus 2 degrees, the Energy Saver valve shall close and mechanical
(DX) cooling shall begin.
The Energy Saver coil shall include 3-way pressure control valves on the condenser circuits and 3-way valve on the economy coil.
Common piping for the energy coil and condensers shall be provided.
B. Energy Saver/Compressor Supplement - Units with Energy Saver shall be provided with compressor supplement if the Energy
Saver is not suffi cient as a stand-alone system. When the incoming water/glycol temperature is below the setpoint of the water
changeover thermostat, the Energy Saver shall be enabled (even if there is no call for cooling). Upon a call for cooling (setpoint
plus deadband), the valve shall open proportionally - 10% for each 0.1° above setpoint plus deadband. The compressor shall
come on at setpoint plus deadband plus 1.3° (the valve shall be 100% open at this point). The compressor shall go off at setpoint
plus 1.3°. The valve shall close proportionally - 10% for each 0.1° below setpoint. An air discharge sensor shall be factory
mounted.
C. Auxiliary Chilled Water Coil - Units shall be provided with an Auxiliary Chilled Water coil. The existing chilled water loop
shall be utilized with the Auxiliary Chilled Water coil. Units shall operate using the chilled water for cooling. Upon a loss of wa-
ter fl ow or an increase in room temperature the system shall bring on compressor (DX) cooling. Separate piping shall be provided
for the chilled water coil and refrigeration connections.
D. Remote Temperature and Humidity Sensors -Units shall be provided with remote temperature and humidity sensors. Sensors
shall be provided in a plastic case for remote mounting. 25 feet of shielded cable shall be provided for fi eld wiring.
E. Disconnect - The environmental control unit shall include a non-automatic disconnect switch mounted in the high voltage
section of the electrical panel. The operating mechanism shall prevent access to the high voltage electrical components until
switched to the “OFF” position. The operating mechanism shall protrude through the decorative door.
F. Smoke Detector - The environmental control unit shall be provided with a smoke detector. The smoke detector shall be mount-
ed with the sensing element in the return air stream. When the smoke detector is activated, it shall immediately shut down the
unit.
G. Condensate Pump - Units shall be provided with condensate pumps. Pumps shall be factory mounted/wired or shipped loose