Specifications

Catalog 1114-1 SmartSource 2-Stage Water Source Heat Pumps Page 65 of 76
Engineering Guide Specications
Solid-State Control System
MicroTechIIISmartSourceControlSystem- Unit shall have a microprocessor- based control system. The unit control
logic shall provide cooling, heating, smart dehumidication, and/or economizer operation as required by the thermostat and/
or sensor. The control system shall provide the following for stand-alone operation:
1. The use of standard non-programmable or programmable wall thermostats.
2. Fan operation simultaneous with the compressor (fan interlock) regardless of thermostat logic.
3. Time delay compressor operation.
4. Compressor short cycle protection of a minimum of three minutes before restart is possible.
5. Random unit start-up
6. Single grounded wire connection for activation of the unoccupied or unit shutdown modes.
7. Night setback temperature setpoint input signal from the wall thermostat.
8. Override signal from wall thermostat to override unoccupied mode for 2 hours.
9. Brownout protection to suspend unit operation if the supply voltage drops below 80% of normal.
10. Condensate overow protection to suspend cooling operation in an event of a full drain pan.
11. Suspended compressor operation upon activation of the refrigerant pressure switch(es).
12. Cooling operation activated for 60 seconds upon activation of the low suction temperature sensor - defrost cycle.
13. Method of defeating compressor, reversing valve and fan time delays for fast service diagnostics.
14. Remote Alarm reset - Provides ability to remotely reset the unit upon a fault condition.
15. Fault Retry clears faults the rst two times they occur within a 24-hour period and triggers automatic lock-out on third
fault.
16. Control shall be congurable to accommodate thermostat or sensor based control.
17. ECM fan motor control.
MicroTech™IIIControlwithLonWorkscommunicationmodule– Unit shall have a microprocessor-based control
system. The unit control logic shall communicate over a LonMark communications network. The unit controller is factory
programmed [LonMark ® 3.4 certied Application Code the current standard for new applications] and tested with all the
logic required to monitor and control heating and cooling operation. The controller sets the unit mode of operation, monitors
water and air temperatures, and can communicate fault conditions via a LonMark communications network. Units with the
MicroTech III and LonWorks communication module include return air, discharge air and leaving water temperature sensors.
Space temperature sensor options include a set-point adjustment, tenant override button, and the capability of substituting the
return air sensor with a wall-mounted room sensor.
MicroTechIIISmartSourceControlw/BACNetCommunicationmodule– Unit shall have a microprocessor-based
control system. The unit control logic shall communicate over a BACNet communications network. The BACnet commu-
nication module shall incorporate an Atmel ARM7 Thumb series MCU and be capable of supporting a full MSTP BACnet
implementation. The microprocessor shall also support SPI compatible communications with the MCU of the MicroTech
III SmartSource unit controller. The physical interface to a BACnet BAS network shall be through an industry standard
RS-485 transceiver capable of existing on an RS- 485 network of up to 64 nodes. The unit controller is factory programmed
and tested with all the logic required to monitor and control heating and cooling operation. The controller sets the unit mode
of operation, monitors water and air temperatures, and can communicate fault conditions via a BACnet communications
network. Units outtted with Microtech III and BACnet Communication modules include return air, discharge air and leaving
water temperature sensors. Space temperature sensor options include a set-point adjustment, tenant override button, and the
capability of substituting the return air sensor with a wall-mounted room temperature sensor.
Eachcommunicatingunitcontrollerperformsthefollowingunitoperations:
■ Enable heating and cooling to maintain space temperature set point at the room sensor
■ Enable fan and compressor operation
■ Monitor all safety controls
■ Monitor discharge and return air temperature
■ Monitor leaving water temperature
■ Relay status of all vital unit functions
■ Support optional control outputs