Specifications

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Control Description Application Protocol
The MicroTech III controller is a stand-
alone microprocessor-based control
board conveniently located in the unit
control enclosure for easy accessibility.
The board is designed to provide ther-
mostat control of a Water Source Heat
Pump using a two-stage wall thermo-
stat. The unit controller provides unit-
wide control of the WSHP and control
of
therstrefrigerantcircuit.
The I/O Expansion Module is an exten-
sion of the Microtech III controller and
provides control of the second refriger-
ant circuit. External LED status lights
display fault conditions to provide easy
troubleshooting and diagnosis of the
second circuit.
The MicroTech III control system
accepts a plug-in L
onWorks commu-
nication module to provide network
communications and added functional-
ity to easily integrate with an existing
BAS. The communication module can
be factory- or field-installed and is
tested with all logic required to monitor
and control the unit.
The MicroTech III controller accepts
a
plug-in BACnet communication
module to provide network commu-
nications and added functionality to
easily integrate with an existing BAS.
The communication module can be
factory-
oreld-installedandistested
with all logic required to monitor and
control the unit.
MicroTech
®
III Controller
The control enclosure houses the major operating electri-
cal controls including the MicroTech® III controller and I/O
expansion module, control transformer, compressor relays and
fan relay. Each component is easily accessed for service or
replacement.
Three unique control choices are offered with the MicroTech
III control system:
■ StandaloneoperationusingaMicroTechIIIcontrollerandI/O
expansion module
■ MicroTechIIIcontrollerwithI/OexpansionmoduleandL
on-
Works® communication module
■ MicroTechIII controllerwithI/Oexpansionmoduleand
BACnet® communication module
Each option features direct quick-connect wiring to all
unit-controlled components for “clean” wiring inside the
control box. Each control circuit board receives power from a
75 VA transformer.
Each unit controller is factory programmed, wired,
and tested for complete control of single zone, stand-
alone operation of your McQuay Water Source Heat
Pump.
Allows for:
•
Control of second refrigeration circuit.
Designed to be linked with a centralized building
automation system (BAS) through a LonWorks com-
munications network for centralized scheduling and
management of multiple heat pumps.
Designed to be linked with a centralized building
automation system (BAS) through a BACnet com-
munications network for centralized scheduling and
management of multiple heat pumps.
Unit-mounted or wall-
mounted thermostat
Wall-mounted thermo-
stat or sensor
LonMark 3.4 certied
BACnet MS/TP
MicroTech III
(Standalone)
Unit Controller
with
I/O Expansion
Module
L
onWorks
Communication
Module
BACnet
Communication
Module
Figure 16: Control Options