Installation and Maintenance IM 660-3
Group: WSHP
Part Number: 106018961
Date: May 2005
MicroTech 2000™ Water Source Heat Pump Unit Controller
© 2005 McQuay International
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Component Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Microprocessor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Yellow Status LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Service Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Red Service LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Temperature Sensing . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Standard Control Features . . . . . . . . . . . . . . . . . . . . . . . . 3
Compressor Short Cycle Protection . . . . . . . . . . . . . . . . . . . . 3
Random Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Delayed Reversing Valve De-energization . . . . . . . . . . . . . . . 3
Condensate Overflow Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Brownout Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
High Pressure Refrigerant Alarm . . . . . . . . . . . . . . . . . . . . . . 3
Low Temperature Refrigerant Alarm . . . . . . . . . . . . . . . . . . . . 3
Low Pressure Refrigerant Alarm . . . . . . . . . . . . . . . . . . . . . . . 3
Change Filter Notification (network units only) . . . . . . . . . . . . 3
Configurable Relay Outputs . . . . . . . . . . . . . . . . . . . . . . . 4
Boilerless System/Auxiliary Heat Relay (LonWorks only) . . . . 4
Boilerless System/Auxiliary Heat Relay (LonMark only) . . . . . 4
MotorizeD Valve Relay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Fresh Air Damper Relay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Timed Output Relay (LonWorks only) . . . . . . . . . . . . . . . . . . . 4
Interface Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
MicroTech Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Wall-Mounted Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Remote Room Set Point Adjustment . . . . . . . . . . . . . . . . . . . . 5
Tenant Override . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Pre-Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Required tools and literature . . . . . . . . . . . . . . . . . . . . . . 6
Water Source Heat Pump Identification . . . . . . . . . . . . . 6
Field Wiring Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Wall Sensor Packages . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Network Communications Units . . . . . . . . . . . . . . . . . . . 6
Set Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Procedure for WSHP . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Description of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Fan Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Unoccupied Operating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Cooling Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Heating Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Occupied Operating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Cooling Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Heating Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Holding Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Tenant Override Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Load Shed Mode (LonWorks only) . . . . . . . . . . . . . . . . . . . . . 9
Optimal Start (LonWorks only) . . . . . . . . . . . . . . . . . . . . . . . . . 9
Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Diagnostic Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Unit Identification (Wink) Command . . . . . . . . . . . . . . . . . . . 10
Alarm Monitoring and Control . . . . . . . . . . . . . . . . . . . . . . . . 10
Clearing Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Alarm Fault Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
High Pressure Fault . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Low Temperature Fault . . . . . . . . . . . . . . . . . . . . . . . . .10
Low Pressure Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Condensate Overflow Fault . . . . . . . . . . . . . . . . . . . . . . 11
Brownout Fault . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Change Filter Notification (network units only) . . . . . . . . . . . 11
Service Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Inputs and Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Analog Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Digital Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Input/Output Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Test Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Microprocessor Problems . . . . . . . . . . . . . . . . . . . . . . . 12
Power Supply Problems . . . . . . . . . . . . . . . . . . . . . . . . . 12
Erroneous Temperature Readings . . . . . . . . . . . . . . . . . 13
Digital Input Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Brownout Fault . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
WSHP Controller Replacement . . . . . . . . . . . . . . . . . . . 13
McQuay is a registered trademark and MIcroTech 2000 is a trademark of McQuay International.
Copyright © 2005 McQuay International. All rights reserved throughout the world.
Introduction
This manual provides informat ion about the MicroTech 2000™
Water Source Heat Pump (WSHP) controller and control
system used in the McQuay International WSHP product lines.
The manual describes the controller’s components, input/output
configurations, and service procedures.
For network installation or commissioning instructions for
new projects, refer to the protocol information document ED
14954. For general information on a particular WSHP unit,
refer to the model-specific installation manual (see Table 1).
Table 1: Model-specific water source heat pump
installation literature
Document number WSHP unit model
lM 407 Vertical WSHP (007 to 060)
lM 439 Large Vertical WSHP (070 to 290)
IM 447 Console Units WSHP
lM 494 WMH/CWH (007 to 019)
lM 526 Horizontal WSHP (007 to 120)
lM 544 CCH/HWH (006 to 060)*
lM 656 Horizontal WSHP (019 to 060)
IM 742 Enfinity Horizontal WSHP (007 to 060)
IM 778 Enfinity Vertical WSHP (007 to 060)
*50 Hz only
WARNING
Electric shock hazard.
Can cause equipment damage, personal injury, or death.
Properly ground equipment. Connections and service to the
MicroTech WSHP controller control panel must be performed
only by personnel knowledgeable in the operation of the
equipment being controlled.
WARNING
Moisture in the control panel can cause personal injury and
improper equipment operation.
When servicing this equipment during rainy weather or high
humidity conditions, protect the electrical components in the
main control panel.
CAUTION
Temperature hazard. Can cause damage to system
components.
The controller is designed to operate in ambient temperatures
from 32°F to 140°F (O°C to 60°C), and in relative humidity up to
95% (noncondensing). The controller can be stored in ambient
temperatures from 40°F to 176°F (40°C to 80°C), and in relative
humidity up to 95% (noncondensing).
CAUTION
Properly commission (page 6) the water source heat pump
before using for temporary heating or cooling. Failure to
properly commission can cause equipment damage not covered
by warranty.
CAUTION
Static sensitive components. Static discharge while
handling electronic circuit boards can cause damage to the
components.
Discharge any static electrical charge by touching the bare
metal inside the main control panel before performing any
service work. Never unplug cables, circuit board terminal blocks,
relay modules, or power plugs while power is applied to the
panel.
CAUTION
This equipment generates and uses radio frequency energy. If
not installed and used in accordance with this manual, it can
cause interference to radio communications. It has been tested
and found to comply with the limits for a Class B digital device,
pursuant to part 15 of the FCC rules. Operation is subject to the
following conditions:
1. This device may not cause harmful interference.
2. This device must accept any interference received, including
interference that may cause undesired operation.
These limits are designed to provide reasonable protection
against harmful interference when the equipment is operated in
a commercial environment. Operation of this equipment in a
residential area is likely to cause harmful interference, in which
case users are required to correct the interference at their own
expense. McQuay International disclaims any liability resulting
from any interference or for the correction thereof.
McQuay IM 660-3 1
General Information
The MicroTech 2000™ WSHP unit controller provides control
of McQuay and AAF water source heat pumps. The controller
enables the mode of operation, monitors the water and air
temperatures, and indicates fault conditions. Each unit
controller is factory programmed, wired, and tested for
effective operation of your McQuay WHSP.
The MicroTech 2000 WSHP controller uses LONW
ORKS
®
technology. One of the following two versions of the
application software is loaded into the controller at the factory.
LONMARK® 3.3 certified application code is the current
standard application code for MicroTech 2000 units. Use
L
ONMARK application code in new applications including:
• Units that operate stand alone.
• Units that are integrated into a L
ONWORKS communication
network for communicating with a building automation
system (BAS) of your choice.
For network integration information, refer to the Protocol
Information document ED 15054. Unit controllers with
L
ONMARK application code have a software identification of
WHPE2E or higher.
LonTalk
®
application code was designed prior to
certification. Use this application software only in existing
systems where an existing MicroTech Communications
Gateway (MCG) or MicroTech Comm uni cations Gateway for
Open Protocol (MCGOP) panel is installed. Use LonTalk
application code in existing systems where:
• MicroTech 2000 WSHPs connect to a McQuay MicroTech
monitor through a MicroTech Communication Gateway
(MCG panel).
• MicroTech 2000 WSHPs connect to a third par ty BAS
system through a MicroTech Communications Gateway for
Open Protocol (MCGOP) panel.
If you choose to upgrade your heat pumps, the other
application code can be installed in the field.
Component Data
Microprocessor
The MicroT ech 200 0 WSHP unit co ntroller is a preprogrammed
microprocessor containing the software required to monitor and
control the unit. The controller supports a minimum of six
analog inputs, four digital inputs and five digital outputs
(including the LED). All electrical connections to the board are
provided by three mass termination style headers. Two of the
headers are designated strictly for factory wiring, the other for a
field wiring harness that terminates to a screw-type terminal
strip on the unit’s exterior.
The controller uses set points and fixed preprogrammed
parameters to maintain unit control (many of the set points and
preprogrammed parameters can be adjusted with a PC over the
network).
Yellow Status LED
A yellow , on-b oard status L ED aids in diagnostics by indicating
the water source heat pump operating mode and alarm
conditions. The yellow LED indicates the unit operating mode
as shown in Ta ble2. For more information on alarms, refer to
the “Alarm monitoring and control” section on page 10.
A remote status LED is provided with all optional
wall-mounted temperature sensor packages. It has the same
function as the on-board status LED. If used, the remote LED
connects to the MicroTech WSHP controller at connection #1
on Terminal Board #1.
Table 2: Status LED indication
Status LED status Mode
On continually Occupied, Occupied Load Shed
On 0.5 sec, Off 5.5 sec Unoccupied
On 5.5 sec, Off 0.5 sec Tenant Override, Override Load Shed
On 0.1 sec, Off 0.1 sec Alarm Condition (Condensate Overflow,
Brownout, Compressor Fault)
Service Pin
A service pin (button) is provided that can be used to cause the
Neuron
network containing its unique 48-bit Neuron ID. This ID is
useful during network commissioning. For another method of
forcing the controller to broadcast its Neuron ID, see “Tenant
override” on page 5.
®
chip to broadcast a message over the LONWORKS
Red Service LED
A red on-board service LED provides diagnostics by
indicating the Neuron chip status. The red LED indicates the
Neuron chip status as shown in Table 3 below.
Table 3: Service LED indication
Service LED status Mode
Off continually (Normal) The Neuron has an application
On continually The Neuron does not have an application
Blink slowly The Neuron has an application but is
and is configured.
or is damaged. (Downloading an
application may correct this.)
unconfigured.
Temperature Sensing
The MicroTech 2000 WSHP unit controller uses negative
temperature coefficient (NTC) thermistors for temperature
sensing. A thermistor chart, which provides voltage-totemperature and resistance-to-temperature conversion data, is
included in Table 9 on page 12. The discharge air temperature
sensor is located at the inlet to the fan. The leaving water
temperature sensor is located in the leaving water line.
2 McQuay IM 660-3
Standard Control Features
Standard features of the MicroTech 2000 WSHP control
include:
• Heating and cooling control from a room sensor
• Monitoring of all equipment protection controls
• Fan and compressor operation
• Monitoring of discharge air temperature
• Monitoring of leaving water temperature
• Status of all vital unit functions
• Optional control outputs
Additional standard features of the MicroTech 2000 control are
provided below.
Compressor Short Cycle Protection
When a compressor is energized, it remains energized for at
least 2 minutes before the temperature control sequence is
allowed to de-energize it. An alarm condition can override this
“minimum-on” timer and stop the compressor if necessary .
When a compressor is de-energized, it remains de-energized
for at least 5 minutes before the temperature control sequence
is allowed to energize it again.
Random Start
The random start feature prevents simultaneous compressor
startup that could otherwise occur after the following events:
• Unit powerup
• Unoccupied to occupied changeover
• Brownout condition
The compressor start delay can be from 5 to 37 seconds and is
determined by the unique 48-bit Neuron chip ID.
Delayed Reversing Valve De-energization
This feature is provided to delay “swishing.” It prevents the
reversing valve from returning to its normal (cooling) position
for a period of approximately 10 seconds after the compressor
is re-energized when the unit is in the heating mode. If
necessary , an alarm condition can override the delay timer and
de-energize the reversing valve with the compressor.
Brownout Alarm
The on-board brownout feature is meant to protect the
compressor contactors from low voltage or “brownout”
conditions. If the supply voltage to the water source heat
pumps is below 82% of the nameplate value, the WSHP
controller detects it, indicates it, and de-energizes the
compressor. After rectifying the browno ut condition (when
supply voltage remains above 90% of nameplate) normal unit
operation resumes.
High Pressure Refrigerant Alarm
If excessive pressure in the refrigeration circuit is detected by
the high pressure switch, the compressor and reversing valve
de-energizes immediately. If the high pressure alarm
disappears, manually reset the unit controller by disconnecting
and reconnecting power to the unit.
Low Temperature Refrigerant Alarm
Upon detection of a low temperature refrigerant alarm, the unit
controller immediately puts the reversing valve in the cooling
position for 60 seconds. After 60 seconds, the compressor is
disabled. If the low temperature alarm disappears, manually
reset the unit controller by disconnecting and reconnecting
power to the unit. The low temperature alarm occurs only
when the unit is in heating mode.
Low Pressure Refrigerant Alarm
Upon detection of a low pressure refrigerant alarm, the unit
controller immediately disables the compressor. If the low
pressure alarm disappears, manually reset the unit controller
by disconnecting and reconnecting power to the unit.
Change Filter Notification (network units
only)
When the water source heat pump fan run time exceeds a
network-adjustable set point, a change filter notification is
indicated locally and over the MicroTech network.
Condensate Overflow Alarm
If a condensate overflow alarm is detected, the unit controller
immediately disables the compressor . Once the overflow alarm
disappears, the unit controller automatically resets the WSHP
unit. The condensate overflow sensor is an exposed ring
terminal located in the condensate drain pan. The condensate
overflow alarm occurs only when the unit is in cooling mode.
McQuay IM 660-3 3
Configurable Relay Outputs
The MicroTech 2000 WSHP controller provides one relay
output that can be configured for the following four options:
• Boilerless system (skin heat) relay
• Motorized water valve relay
• Fresh air damper relay
• Timed output relay (L
ONWORKS only)
These options can affect installation requirements and unit
control. If more than one configurable relay output option is
required, the MicroTech 2000 WSHP auxiliary board is
required to provide the other three outputs. The MicroTech
2000 WSHP auxiliary board typically is factory mounted only
in 2-compressor-circuit WSHP units. Only three relay outputs
are available for use as configurable relay outputs in 2-circuit
WSHP units. All configurable relay outputs are set to “no
function” by default and must be field configured. A
description of the four relay options follows.
Boilerless System/Auxiliary Heat Relay
(LONWORKS only)
The relay receives loop water temperature input from the
MicroTech Loop Water Controller through the gateway panel
and provides relay output to electric heat on a call for heat
after loop temperature falls.
Boilerless System/Auxiliary Heat Relay
(LONMARK only)
The relay output energizes when the space temperature reaches
the heating set point and de-energizes when the space
temperature exceeds the heating set point plus a configurable
differential set point (defaulted to 3°F).
Motorized Valve Relay
Figure 1: First control signal output
Terminal boards
(located externally on the WSHP chassis)
12345 67
IMPORTANT: To use onboard 24 VAC,
change the jumper PF1 on the
MicroTech 2000 controller
from factory default pins 1 and 2 to
pins 2 and 3.
Figure 2: Second control signal output
Terminal located on
MicroTech 2000 auxilliary board
J6
pilot duty relay
4321
24 VAC
pilot duty relay
(by others)
Use contacts as needed for option.
Figure 3: Third control signal output
Terminal located on
MicroTech 2000 auxilliary board
J7
4321
24 VAC
pilot duty relay
(by others)
EL UPC
24 VAC
(by others)
(by others)
24 VAC24 VAC
(by others)
24 VAC
The relay provides output to the motorized valve to shut off
water through the unit when the compressor is not operating.
Fresh Air Damper Relay
The relay provides output to the open damper whenever the
fan is operating in the occupied cycle.
Timed Output Relay (LONWORKS only)
The relay provides output to an auxiliary load to control its
operation based on a specific time schedule different from that
of the heat pump unit.
4 McQuay IM 660-3
Use contacts as needed for option.
Figure 4: Fourth control signal output
Terminal located on
MicroTech 2000 auxilliary board
J10
4321
24 VAC
pilot duty relay
(by others)
Use contacts as needed for option.
(by others)
24 VAC
Interface Features
MicroTech Network
Control sequencing, stop/start, equi pment protection
monitoring, and fault resets can be accomplished through a
network connection. The following unique values and
parameters can be accessed for each unit (refer to Protocol
Document ED15054 for more information):
• Return air and discharge air temperatures
• Compressor, fan and reversing valve status
• High pressure, low temperature, brownout and drain pan
status
• Occupied and unoccupied heat and cool set points
• Auto/manual and occupied/unoccupied fan control
• Mode, fault, system, schedule and set point operation
• Compressor starts and fan run hours
• Load shed level (L
ONWORKS only)
• Tena nt override status
In addition, the following unique operation and maintenance
parameters can display for each unit:
• Leaving water temperature
• Return air temperature set point (wall sensor adjustment)
• Adaptive optimal start (L
ONWORKS only)
• Occupied/unoccupied (on/cycle) fan mode
• Room temperature warning
• Filter changes from fan hours
• Compressor management: on/off differential, minimum off
time, minimum on time
Communications Failure (L
ONWORKS): If the network
communication link fails for any reason, the affected WSHP
controller remains operational. Its operating mode will be the
last received over the network unless power is cycled, and then
it defaults to occupied. Its minimum position, heating, and
cooling set points will be those last received over the network,
regardless of whether power is cycled.
Communications Failure (LONM
ARK
):
If the network
communication link fails for any reason, the affected WSHP
controller remains operational. The status of its heating and
cooling set points as well as its occupancy and other network
adjustable settings depends upon whether the BAS is using
LONWORKS
bindings with associated heartbeats.
Wall-Mounted Sensor
There are four optional wall sensor packages available. All
include a remote status LED and tenant override button. Set
point adjustment and thermometer are optional features.
The wall-mounted sensor must be field installed and field
wired to the water source heat pump. Terminal Board #1
provides the connections for all room temperature sensor field
wiring. Refer to the unit wiring diagram provided and to IM
529, MicroTech Room Temperature Sensors, for information
on wall sensor package installation.
Figure 5: Wall-mounted temp sensor wiring
WSHP Wall sensor
Sensor LED
Tenant override
Sensor input
Sensor common
Table 4: Maximum wire length to sensors
TB1-1
TB1-2
TB1-3
TB1-4
Gauge Length (ft.)
18 AWG 625
20 AWG 380
22 AWG 260
Red
Green
White
Black
Remote Room Set Point Adjustment
The remote set point adjustment potentiometer allows the room
set point to be adjusted up or down by as much as 3°F (1.7°C).
It is available with several of the optional wall sensor packages.
Tenant Override
A wall-mounted tenant override switch is standard on all McQuay
MicroTech Room Temperature Sensors. Pressing and holding the
tenant override button for 1.0 to 6.0 seconds puts the unit into
tenant override mode for a set time period (default = 60 minutes).
Press the tenant override button again for 1.0 to 6.0 seconds and
the unit returns to unoccupied mode by default. A separate
configuration property is available that allows users to extend the
tenant override period for up to 60 minutes with a second button
press. Except for the fact that it is temporary, the tenant override
operating mode is identical to the occupied operating mode.
LONWORKS only: Pressing and holding the tenant override
button for at least 6 seconds but not more than 10 seconds
activates the network “query address” mode, indicating the
unit address in question at the MicroTech gateway panel.
L
ONWORKS only: Pressing and holding the tenant override
button more than 10 seconds activates the network
“self-configure” mode, requesting the assignment of the next
sequential address from the MicroTech gateway panel.
L
ONMARK only: Similar to pressing the service pin, pressing
and holding the tenant override button for more than 10
seconds causes the Neuron chip to broadcast a message over
the L
ONWORKS network containing its unique 48-bit Neuron
ID. This is useful during network commissioning.
McQuay IM 660-3 5
Commissioning
The following commissioning procedures pertain to water
source heat pumps equipped with the MicroT ech Water Source
Heat Pump Controller. These procedures must be performed in
addition to the mechanical and electrical system
commissioning procedures outlined in the model-specific
installation literature (listing provided in Table 1 on page 1).
WARNING
Electrical Shock Hazard. Can cause severe injury or death.
Failure to bond the frame of this equipment to the building
electrical ground with the grounding terminal provided or other
acceptable means can result in electrical shock. Service must
be performed only by qualified personnel.
CAUTION
Before applying power to any unit, closely follow the pre-start
procedures in the model-specific installation literature. See
Table 1 on page 1.
Pre-Start
Required tools and literature
The following tools and additional literature may be required
to properly commission a MicroTech 2000 Water Source Heat
Pump Controller.
It is extremely important to correctly locate each water source
heat pump according to job requirements. The proper location
should have been determined during the installation process.
Nevertheless, verify proper location during the commissioning
process.
Field Wiring Check
A unit wiring diagram is provided with each unit, along with a
model-specific Installation and Maintenance Guide. Before the
commissioning process begins, refer to this literature and,
using the following check lists, thoroughly check the electrical
installation.
Wall Sensor Packages
1 Check that the cable is twisted and shielded with drain wire
(Belden 8729 or equivalent).
2 Check that four conductors are available.
3 Check that the conductors are terminated at the unit and at
the wall sensor package to screw terminal board #1 in
accordance with the field wiring diagram, on which
terminals are clearly labeled. Terminal 4 is used for both
the room sensor common and the shield wire.
4 Check the cable length between the wall sensor package
and its water source heat pump controller. (See Table 4 on
page 5.)
Tools:
• Digital voltmeter
• Digital ohmmeter
• Digital thermometer
• General technician’s tools
• PC equipped with Monitor™ software (Network Water
Source Heat Pumps only)
Literature:
• Model-specific water source heat pump installation bulletin
(See Table 1 on page 1.)
• Program-specific sequence of operation bulletin
• MicroTech Monitor Program User’s Manual (if PC is used)
Water Source Heat Pump Identification
Although the water source heat pumps look similar, there are
significant internal differences that are defined by the model
number code string. In addition to the basic heating and
cooling equipment, the model number code string specifies
which factory-configured options are provided. These options
determine the internal wiring configuration and the field
wiring requirements.
Network Communication Units
1 Check that the cable is a twisted, unshielded pair of copper
strand conductors.
2 Check that the conductors are terminated properly.
3 Check that the conductors are terminated at the MicroTech
gateway panel according to the field wiring diagram
supplied with the panel.
Set Points
The Water Source Heat Pump set point values are held in
memory and can be modified only over the MicroTech
network. Initially, before any changes are made over the
network, the WSHP uses the default factory set points shown
in Table 5.
Start-up
Following are WSHP start-up procedures for each
communication type. The start-up procedure must be
performed by a qualified technician for every WSHP on a job.
Connections for network wiring are made at terminals 5 and 6
of Terminal Board #1. The FTT-10 (free topology transceiver)
on the MicroTech WSHP 2000 Controller is polarity
insensitive; thus polarity issues need not be addressed.
6 McQuay IM 660-3
Commissioning
Procedure for WSHP
1
Apply power to the unit. Turn the main power switch to ON.
2 Check the status LED and operating mode changeover
devices. The status LED should illuminate 30 to 40 seconds
Table 5: Network WSH P de fau lt se t points and adjustability
Description Factory-programmed set point Adjustability range
Occupied heating set point 70°F (21°C) 35°F to 120°F (1.7°C to 49°C)
Occupied cooling set point 74°F (23°C) 35°F to 120°F (1.7°C to 49°C)
Fan—occupied On On, cycle, heat, cycle/cool on
Unoccupied heating set point 60°F (16°C) 35°F to 120°F (1.7°C to 49°C)
Unoccupied cooling set point 85°F (29°C) 35°F to 120°F (1.7°C to 49°C)
Fan—unoccupied Cycle On, cycle
Tenant override—1st press 1:00 Off, 0:30 to 8:00
Tenant override—2nd press Off Off, 0:30 to 8:00
Differential 2°F (1.2°C) 1°F to 10°F (0.6°C to 5.6°C)
Auto/Manual Auto Manual (occupied, unoccupied, fan only, off)
Next filter change (hours) 600 100 to 5000
Clock schedule 1 Up to 32
Load shed start level Off Off, 1 to 7
Tenant set point adjustment Off (0°F, 0°C) Off, on (3°F to 1.7°C)
Low temperature warning 55°F (13°C) 35°F (1.7°C)—high not used
High temperature warning 95°F (35°C) 120°F (49°C)—low not used
after powerup. If a wall sensor package is used, the remote
status LED should also illuminate.
3 Verify that the water source heat pump is operating
according to its sequence of operation as outlined in the
“Description of Operation” section on page 8.
McQuay IM 660-3 7
Description of Operation
Fan Operation
When the unit is in heating or cooling mode, the fan is on. When
a compressor is running, the fan is on. In the unoccupied mode, if
the fan unoccupied set point is on (not cycle) or if a compressor is
running, the fan remains on. In the occupied mode, if the fan
occupied set point is on (not cycle), the fan is always on. If the set
point is heat cycle/cool on, the fan cycles with the compressor in
heating and is on continuously in cooling.
Unoccupied Operating Mode
The descriptions below assume that the factory default
unoccupied fan setting is used and the fan cycles with the
compressor. If the unoccupied fan setting is adjusted to ON,
the fan runs continuously.
Cooling Operation
The fan energizes and the reversing valve de-energizes when the
space temperature rises to the UCS set point (see note below). If
the reversing valve was previously energized, the compressor
energizes after a 10-second delay. If the reversing valve does not
change state, the compressor is energized immediately.
Once the compressor energizes, the start-to-stop (minimum)
timer overrides normal temperature control and keeps it
energized for at least 2 minutes (fixed.) The compressor
de-energizes when the space temperature falls below the UCS
set point (to a minimum temperature of UCS–DIFF).
The fan also de-energizes when the space temperature falls
below the UCS set point; however, controller code prevents the
fan from stopping until 12 seconds after the compressor stops.
Note – During normal (non-alarm) operation, the compressor is
disabled if the stop-to-stop (minimum off) timer has not
expired (5 minutes, fixed).
Heating Operation
The fan and reversing valve energizes when the space temperature
falls to the UHS set point (see note below). If the reversing valve
was previously de-energized, a time delay of approximately 10
seconds must expire before the compressor energizes.
Once the compressor energizes, the start-to-stop (minimum
on) timer overrides normal temperature and keeps it energized
for at least 2 minutes (fixed). The compressor de-energizes
when the space temperature rises above the UHS set point to a
maximum temperature of USHS + DIFF).
Occupied Operating Mode
The descriptions below assume that the factory default
occupied fan setting is used and that the fan is always on. If the
occupied fan setting is adjusted to CYCLE, the fan cycles with
the compressor.
Cooling Operation
The fan energizes and the reversing valve de-energizes when
the space temperature rises to the OCS set point (see note
below). If the reversing valve was previously energized, the
compressor energizes after a 10-second delay. If the reversing
valve does not change state, the compressor energizes
immediately.
Once the compressor energizes, the start-to-stop (minimum)
timer overrides normal temperature control and keeps it
energized for at least 2 minutes (fixed.) The compressor
de-energizes when the space temperature falls below the OCS
set point (to a minimum temperature of OCS–DIFF).
The fan also de-energizes when the space temperature falls
below the OCS set point; however, controller code prevents
the fan from stopping until 12 seconds after the compressor
stops.
Note – During normal (non-alarm) operation, the compressor is
disabled if the stop-to-stop (minimum off) timer has not
expired (5 minutes, fixed).
Heating Operation
The reversing valve energizes when the space temperature falls
to the OHS set point (see note below). If the reversing valve
was previously de-energized, the compressor energizes after a
10-second delay.
Once the compressor energizes, the start-to-stop (minimum
on) timer overrides normal temperature and keeps it energized
for at least 2 minutes (fixed). The compressor is de-energized
when the space temperature rises above the OHS set point to a
maximum temperature of OSHS + DIFF).
The fan is also de-energized when the space temperature rises
above the OHS set point; however, the controller code
prevents the fan from stopping until 12 seconds after the
compressor stops.
Note – During normal (non-alarm) operation, the compressor is
disabled if the stop-to-stop (minimum off) timer has not
expired (5 minutes, fixed).
The fan also de-energizes when the space temperature rises
above the UHS set point; however, the controller code
prevents the fan from stopping until 12 seconds after the
compressor stops.
Note – During normal (non-alarm) operation, the compressor is
disabled if the stop-to-stop (minimum off) timer has not
expired (5 minutes, fixed).
8 McQuay IM 660-3
Description of Operation
Holding Mode
If the unit comes out of the heating or cooling modes into the
holding mode, the compressor de-energizes after the 2-minute
timer expires. The unit must stay in the holding mode with the
compressor off for 30 seconds before it is allowed to go into
the heating or cooling states. During this time, the reversing
valve is not allowed to switch states.
Tenant Override Mode
A wall-mounted tenant override switch is available for use
with all MicroTech 2000 WSHP unit controllers. Pressing and
holding the tenant override button for 1.0 to 6.0 seconds puts
the unit into tenant override mode for a set time period (default
= 60 minutes). Press the tenant override button again for 1.0 to
6.0 seconds and the unit returns to unoccupied mode by
default. A separate configuration property is available that
allows users to extend the tenant override period up to 60
minutes with a second button press. Except for the fact that it
is temporary, the Tenant Override operating mode is identical
to the Occupied operating mode.
L
ONWORKS only: Pressing and holding the tenant override
button for at least 6.0 seconds but not more than 10 seconds
activates the network “query address” mode, indicating the
unit address in question at the MicroTech gateway panel.
L
ONWORKS only: Pressing and holding the tenant override
button more than 10 seconds activates the network
“self-configure” mode, requesting the assignment of the next
sequential address from the MicroTech gateway panel.
L
ONMARK only: Similar to pressing the service pin, pressing
and holding the tenant override button for more than 10
seconds causes the Neuron chip to broadcast a message over
the Lon network containing its unique 48-bit Neuron ID. This
is useful during network commissioning.
Load Shed Mode (LONWORKS only)
When the network load shed level is less than or equal to the
load shed threshold setting in the unit, load shedding is
activated. The amount the controller adjusts the set points
depends upon the network threshold level and the step value.
Optimal Start (LONWORKS only)
Whether heating or cooling, every start is an optimal start if
the optimal start window is greater than zero. The unit
controller optimal start logic examines past data to calculate
the optimal time to change the heat pump from unoccupied to
occupied operation. During optimal start, load shed and tenant
override are ignored.
If this option is selected, two hours (adjustable) prior to
scheduled time of occupancy, the unit begins calculating the
time required to bring the space temperature to occupied set
point. At the appropriate moment, the unit energizes and
begins heating or cooling as necessary. The unit notes actual
time to reach occupied set point and compares it to calculated
time. If the difference exceeds 15 minutes, the unit adjusts its
factors to adapt to actual room conditions.
Faults
The WSHP controller examines fault conditions in the order of
ascending priority. Higher priority faults do not override lower
priority faults. A higher priority fault must be manually
cleared before the WSHP controller can indicate a second,
lower priority fault. If the unit has only one compressor, faults
on the second circuit are ignored. For units with two
compressors, second circuit faults are lower priority than first
circuit faults. In a dual circuit unit, a second circuit fault
indication does not disable the unit unless the first circuit also
fails.
McQuay IM 660-3 9
Diagnostic Service
Unit Identification (Wink) Command
The unit identification function allows verification of an
individual unit network address without opening the unit
access panels. The compressor shuts off during this period and
the minimum off timer must expire before the compressor is
allowed to run again.
Upon receiving a “wink” command from a network
management node, the heat pump exhibits the following
identification sequence (status LED and fan sequences occur
simultaneously):
• Status LED: Flashes (on 0.5 sec, off 0.5 sec) for 15 seconds.
• Fan: The heat pump fan turns off for 5 seconds, turns on for
5 seconds, then off again for 5 seconds.
Alarm Monitoring and Control
The water source heat pump controller is programmed to
monitor the water source heat pump for specific alarm
conditions that may occur on the various model types. If an
alarm condition exists and is detected by the controller, a
“fault” occurs. The water source heat pump controller
indicates that a fault has occurred at the status LED (on-board
or remote) and executes appropriate control actions for the
alarm conditions.
During a fault condition, the status LED flashes constantly (on
0.1 second, off 0.1 second) until the fault is cleared. Refer to
“Test Procedures” on page 12 of the “Service Information”
section for information on troubleshooting digital input faults.
Clearing Faults
Before any fault can be cleared, the alarm conditions that
caused it must have returned to normal. When the alarm
conditions are gone, a fault may be cleared either
automatically or manually, as follows.
• An auto reset fault immediately clears whenever the alarm
conditions that caused it disappear.
• To clear a manual reset fault, cycle power to the controller.
Note – Investigate and eliminate the cause of a manual reset
fault before placing the unit back into service.
Alarm Fault Descriptions
Table 6 below describes the alarm faults, how they are
triggered, the factory settings that trigger them and how they
are reset. A detailed discussion of each follows.
Table 6: Alarm an d fault code summary
Fault Trigger Factory setting
High pressure Hardware
Low pressure Hardware
Condensate
overflow
Brownout Software
Hardware
Opens at 395 ± 10 psig
Closes at 250 ± 25 psig
Opens at 7 ± 3 psig
Closes at 22 ± 7 psig
Conductivity trip point:
2.5 micro ohms
Line voltage ± 82%of
nameplate voltage
High Pressure Fault
The “High Pressure” fault indicates that the high pressure
switch input (J4-9) sensed an open circuit while the controller
was calling for the compressor to run.
The high pressure switch (HP) is wired in series with the
compressor relay output (J4-5) and the compressor relay coil.
Therefore, if a high pressure condition occurs, the switch
immediately shuts down the compressor; then unit operation is
disabled by the WSHP controller software. For information on
troubleshooting digital input faults, see “Test Procedures” on
page 12.
Effects (as applicable):
• The compressor immediately de-energizes.
• The software disables normal unit operation until the fault
condition is manually corrected.
Low Temperature Fault
The “Low Temperature” fault indicates that the low
temperature switch input (J4-12) sensed an open circuit while
the controller was calling for the compressor to run.
The low temperature switch opens when the temperature falls
below its set point (model and size dependent). For
information on troubleshooting digital input faults, see “Test
Procedures” on page 12.
Fault reset
(Clear)
Manual
Manual
Manual
Auto
10 McQuay IM 660-3
Effects:
• Unit changes to cooling for 60 seconds for coil defrost.
• After 60 seconds in cooling, the software immediately
de-energizes the compressor and fan.
• The software disables normal unit operation until the fault
condition is manually corrected.
Diagnostic Service
Low Pressure Faults
The “Low Pressure” fault indicates that the low pressure
switch input (J4-11) sensed an open circuit while the controller
was calling for the compressor to run. The low pressure switch
opens when the temperature falls below its set point. For
information on troubleshooting digital input faults, see “Test
Procedures” on page 12.
Effects:
• The compressor immediately de-energizes.
• The software disables normal unit operation until the fault
condition is manually corrected.
Condensate Overflow Fault
The “Condensate Overflow” fault indicates that the condensate
overflow sensor (J4-14) sensed a grounded signal while the
controller was calling for the compressor to run. For
information on troubleshooting analog input faults, see “Test
Procedures” on page 12.
Effects:
• The compressor immediately de-energizes.
• The software disables normal unit operation until the fault
condition is manually corrected.
Brownout Fault
The “Brownout” fault indicates the water source heat pump is
sensing low voltage levels. It is designed to protect the
compressor and contactors from low line voltage or
“brownout” conditions.
The controller is programmed with a brownout set point that
corresponds to 82% of the water source heat pump’s nameplate
line voltage value. If the water source heat pump controller
senses a voltage level less than its set point for more than 1
second, it triggers the brownout fault. The fault resets
automatically when the sensed voltage remains at or above a
level corresponding to 90% of the nameplate value for a period
of 1 second. For information on troubleshooting this alarm, see
“Test Procedures” on page 12.
Effects (as applicable):
• The compressor immediately de-energizes.
Change Filter Notification (network units
only)
The “Change Filter” notification indicates that the fan has
operated longer than the set number of hours. Typically, this
warning is used to alert the building operator to replace the
filter. To clear the notification, reset the filter timer at the
network PC.
Effect:
• An alarm message identifying the water source heat pump
network address and time of occurrence is sent to the
network printer.
McQuay IM 660-3 11
Service Information
Inputs and Output s
Analog Inputs
The MicroTech WSHP unit controller has six standard analog
inputs. See Table 7. The controller can sense temperatures in
the range of 0° to 158°F (–18° to 70°C).
Table 7: Analog inputs
Description Location
Discharge air temp sensor Inlet to fan
Leaving water temp sensor Leaving water line
Condensate overflow sensor Condensate drain pan
Brownout (supply voltage) sensor On board
Room air temp sensor Remote basic wall sensor
Tenant override/set point adjust Remote wall sensor
Digital Inputs
The water source heat pump controller has four standard digital
inputs. See Table 8. Digital input conditioning includes RC
filtering with a time constant of at least 4.7 milliseconds. The
base module provides additional filtering using software filtering
techniques.
The digital inputs sense the presence or absence of an external
24 VAC ± 20% power source with a minimum of 10 mA AC
current flowing through the following isolated contacts:
Table 8: Digital inputs
Description Location
Refrigerant high pressure—N/C HP switch
Refrigerant low pressure—N/C LP switch
Refrigerant low temp—N/C LT switch
Remote start/stop—N/O Remote switch
Refer to the wiring diagram supplied with your unit for
specific wiring details.
Digital Outputs
All digital outputs, with the exception of the on-board and offboard status LEDs, are capable of controlling electromechanical or
solid state relays. They switch inductive loads at 24 VAC ± 20%,
0.4 pF and at the steady state AC RMS currents listed in Table 9
(10x single cycle surge currents are assumed on initial turn on).
The on-board and off-board status LEDs are controlled by one of
the Neuron’s I/0 pins capable of PuIse Width Modulation.
Table 9: Digital outputs
Description Type/AC RMS current rating
Fan contactor
Compressor contactor
Reversing valve
solenoid
On-board status LED
Off-board status LED
Multi-purpose (spare)
isolated E/M contacts
E/M pilot duty relay at 300 mA-AC
(SPST N/O contacts)
E/M pilot duty relay at 300 mA-AC
(SPST N/O contacts)
E/M pilot duty relay or SS random turn on Triac
at 600 mA-AC (SPST N/O contacts)
Yellow
DC-sourced signal—current limited to 10 mA-DC
E/M pilot duty relay at 300 mA-AC
(SPST N/O contacts)
Input/Output Tables
All WSHP controller input and output connections and their
corresponding water source heat pump components are shown
in Table 10 on page 14.
Test Procedures
Microprocessor Problems
The status LED indications can aid in WSHP controller
diagnostics. Approximately 40 seconds after power is applied to
the WSHP, the status LED should illuminate as shown in
Table 2 on page 2. If not, either there is a software problem or
the WSHP controller is defective.
Power Supply Problems
The WSHP controller requires a 24 VAC power supply. It is
connected to the board at the section labeled 24V GND and
24 VAC (terminals J41 and J42). Refer to the unit wiring
diagram. If you suspect a problem with the WSHP controller
power, check the following:
1 Verify that the main power switch is at ON.
2 Check the voltage at the secondary of the transformer. It
should be approximately 24 VAC (load dependent).
12 McQuay IM 660-3
Service Information
Erroneous Temperature Readings
If you suspect that the WSHP controller is operating using
erroneous temperature data, check the sensors using the
following procedure:
1 Measure the temperature at the suspect sensor using an
accurate thermometer.
2 Determine the sensor’s analog input number. Refer to the
unit wiring diagram or to the input/output tables (Table 10).
3 Remove the connector from its WSHP controller terminals
and measure the resistance of the sensor (through the
sensor connections).
4 Using the thermistor chart (T able 11), compare this value to
the measured temperature.
5
If the measured resistance and temperature mat ch, the WSHP
controller may require factory service, or it may be defective.
6 If the measured resistance and temperature do not
match, either there is a wiring problem or the sensor is
defective. Check the wiring connection and the sensor
circuit wiring for defects.
Digital Input Faults
A digital input fault usually is caused by high-pressure,
low-pressure or low-temperature alarm conditions resulting
from mechanical problems in the water source heat pump. It
also can be caused by a problem in the digital input circuit.
Below is a procedure to use to check for problems in the
digital input circuit. If the probable cause of the fault is found
using this procedure, attempt to clear the fault by cycling
power to the WSHP. If the probable cause of the fault is not
found using this procedure, assume that mechanical problems
exist and have a qualified technician service the unit before
attempting to reset the WSHP Controller.
1 Check the voltage at the secondary of transformer; it should
be approximately 24 VAC.
2 Determine the switch’s digital input number. Refer to the
unit wiring diagram or to the input/output tables (Table 10).
3 Check the wiring and connections throughout the digital
input circuit.
4 Measure the resistance through the switch contacts (with at
least one wire disconnected). The switches normally are
closed.
Brownout Fault
The WSHP controller senses the AC voltage at the power input
section terminals J41 and J42 (see unit wiring diagram). If the
voltage at these terminals is less than 19.68 VAC for at least 1
second, the brownout fault occurs. The fault automatically
clears if the voltage at the terminals remains greater than 21.6
VAC for at least 1 second.
If a brownout fault occurs, check the line voltage to the water
source heat pump. If it is less than 82% of the nameplate value,
contact the power company. If the line voltage remains greater
than 90% of the nameplate value for more than 1 second but
the fault does not reset, perform the following procedure:
1 Measure the voltage between terminals J41 and J42 on the
WSHP controller.
2 If the voltage is low or fluctuates around 19.68 VAC, the
WSHP controller is functioning properly. Go on to step 2.
3 If the voltage remains above 21.6 VAC for 1 second but the
fault does not reset, the WSHP controller is defective.
4 Check the primary and secondary voltages of the power
supply transformers.
5 Check for faulty wiring or connections throughout the
power supply circuit.
WSHP Controller Replacement
Data relating to the water source heat pump controller
configuration and characteristics are stored at the factory when
each unit is built and tested. If a WSHP controller is defective
and must be replaced, its unit-specific software (defined by the
above data) must be loaded into the replace ment controlle r at the
factory. To do this, the factory needs the following information:
• Full model number
• Serial number
• Date code for time of manufacture
• Software version of code loaded in the controller
The unit model and serial numbers are listed on the unit
dataplate. The date code and software version of code are
printed on the MicroTech unit controller adhesive-backed
label. This information must be included with the replacement
WSHP controller part order.
McQuay IM 660-3 13
Service Information
Table 10: Inputs and outputs for WSHP units
Connection Component description
J1-1 / TB#2-E Remote digital source
J1-2 / TB#2-L Remote digital signal
J1-3 / TB#2-U Spare relay normally closed
J1-4/TB#2-P Spare relay common
J1-5 / TB#2-C Spare relay normally open
J2-6 / TB#1-1 Room sensor LED
J2--7 / TB#1-2 Tenant override
J2-8 / TB#1-3 Room sensor input
J2-9 / TB#1-4 Room sensor common
J2-10 / TB#1-5 LonTalk connection
J2-11 /TB#1-6 LonTalk connection
J2-12 / TB#1-7 24 VA C common
J41 24 V ground
J4-2 24 VAC
J4-3 Fan relay output
J4-4 Fan relay co m mon
J4-5 Compressor contactor output
J4-6 Compressor contactor common
J4-7 Reversing valve solen oid output
J4-8 Reversing valve solen oid common
J4-9 High pressure switch signal
J4-10 Low pressure switch source
J4-11 Low pressure switch signal
J4-12 Low temperature switch signal
J4-13 Low temperature switch source
J4-14 Condensate overflow sensor
J5-8 Leaving water tempera t ur e sensor input
J5-9 Leaving water tempera t ur e sensor common
J5-10 Discharge air temperature sensor input
J5-11 Discharge air temperature sensor common
J6-1-7 Auxiliary module connections
Table 11: Thermistor chart
°C 10 k ohm °F °C 10 k ohm °F
18 8.654 0 28 0.8777 82
17 8.173 1 29 0.8408 84
16 7.722 3 30 0.8056 86
15 7.298 5 31 0.7721 88
14 6.900 7 32 0.7402 90
13 6.526 9 33 0.7098 91
12 6.175 10 34 0.6808 93
11 5.845 12 35 0.6531 95
10 5.534 14 36 0.6267 97
9 5.242 16 37 0.6015 99
8 4.967 18 38 0.5774 100
7 4.708 19 39 0.5545 102
6 4.464 21 40 0.5326 104
5 4.234 23 41 0.51 16 106
4 4.017 25 42 0.4916 108
3 3.812 27 43 0.4725 109
2 3.620 28 44 0.4543 111
1 3.438 30 45 0.4368 113
0 3.266 32 46 0.4201 115
1 3.104 34 47 0.4041 117
2 2.951 36 48 0.3888 118
3 2.806 37 49 0.3742 120
4 2.669 39 50 0.3602 122
5 2.540 41 51 0.3468 124
6 2.418 43 52 0.3340 126
7 2.302 45 53 0.3217 127
8 2.192 46 54 0.3099 129
9 2.089 48 55 0.2987 131
10 1.990 50 56 0.2878 133
11 1.897 52 57 0.2775 135
12 1.809 54 58 0.2675 136
13 1.726 55 59 0.2580 138
14 1.647 57 60 0.2489 140
15 1.571 59 61 0.2401 142
16 1.500 61 62 0.2317 144
17 1.432 63 63 0.2236 145
18 1.368 64 64 0.2158 147
19 1.307 66 65 0.2084 149
20 1.249 68 66 0.2012 151
21 1.194 70 67 0.1944 153
22 1.142 72 68 0.1878 154
23 1.092 73 69 0.1814 156
24 1.045 75 70 0.1753 158
25 1.000 77 71 0.1695 160
26 0.9572 79 72 0.1638 162
27 0.9165 81 73 0.1584 163
14 McQuay IM 660-3
McQuay IM 660-3 15
McQuay IM 660-3 16
McQuay Training and Development
Now that you have made an investment in modern, efficient McQuay equipment, it s care should be a high priority.
For training information on all McQuay HVAC products, please visit us at www.mcquay.com and click on training, or
call 540-248-9646 and ask for the Training Department.
This document contains the most current product information as of this printing. For the most up-to-date product
information, please go to www.mcquay.com.
© 2005 McQuay International • www.mcquay • 800-432-1342 05/05
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