(CONSISTING OF: C7046C DISCHARGE AIR SENSOR OR C7150B MIXED AIR SENSOR, C7400A
OR
SOLID STATE ENTHALPY SENSOR
OR
M8405 DAMPER ACTUATORS OR MODULATING DIRECT COUPLED ACTUATORS (MS7505),
T6031H THERMOSTAT AND W7459 OR W7212 SOLID STATE ECONOMIZER LOGIC MODULE)
C7650A SOLID STATE TEMPERATURE SENSOR, M7415
PRODUCT DATA
FEATURES
C7046C
M7415/M8405
C7150B
W7459A,C
W7212
C7400A/C7650A
T6031H
APPLICATION
The Solid State Economizer System provides an economical
method of providing cooling air by incorporating outdoor air in
the first stage of cooling in heating, ventilating and air
conditioning (HVAC) systems. The Solid State Economizer
System consists of the C7046C Discharge Air Sensor or
C7150B Mixed Air Sensor, C7400A Solid State Enthalpy
Sensor or C7650A Solid State Temperature Sensor, M7415
or M8405 Damper Actuators or Modulating Direct Coupled
Actuators (MS7505), T6031H Thermostat and W7212 or
W7459A,C Solid State Economizer Logic Module.
C7046C Discharge Air Sensors have probe lengths of 8 in.
(203 mm) and nominal sensor resistance of 3000 ohms at
77°F (25°C).
• No setting or calibration required.
• Solid state components not affected by dust or dirt.
• Fast reacting.
• Rugged aluminum insertion probe.
C7150B Mixed Air Sensor is used with the W7212/W7459
Economizer Module to sense mixed or discharged air in rooftop packaged air conditioning equipment.
• No setting or calibration required.
C7400A Solid State Enthalpy Sensor and C7650A Solid State
Temperature Sensors are used with the W7212/W7459 Solid
State Economizer Logic Module to sense outdoor and return
air enthalpy or temperature.
• C7400A senses and combines temperature and
humidity (enthalpy) of outdoor air (heat index).
• C7650A senses temperature only.
• When enthalpy/temperature of outdoor air increases,
the outdoor air damper closes to a preset minimum
position.
• When enthalpy/temperature of outdoor air is low, the
outdoor air damper opens to reduce the building
cooling load.
• Additional economizer savings are achieved when two
C7400A Solid State Enthalpy Sensors are connected to
one Logic Module for differential enthalpy changeover
control.
Settings and Adjustments: W7212 ................................... 18
Checkout and Troubleshooting ........................................ 19
Checkout and Troubleshooting: W7212 ........................... 31
63-2484-2
SOLID STATE ECONOMIZER SYSTEM
M7415 and M8405 Damper Actuators are 25 lb-in. spring
return damper actuators that provide modulating or threeposition control of economizer systems on HVAC equipment.
• M7415 Damper Actuator provides modulating control
of economizer dampers from a thermistor mixed-air or
discharge sensor to maintain 56°F (13°C) air
temperature.
• W7459 logic modules may plug directly onto the
M7415.
• High impact, glass-fiber reinforced, plastic case is
rugged, lightweight and corrosion resistant.
M7215 Damper Motors provide 25 lb-in. torque with spring
return and 2–10 Vdc modulating control of economizer systems on HVAC equipment.
• M7215 Damper Motors provide modulating control of
economizer dampers from a 2–10 Vdc controller.
• W7212 logic module may plug directly onto the M7215.
T6031H Thermostat acts as changeover thermostat.
• Switches enclosed to resist effects of dust and
moisture.
• Warmer–Cooler temperature scale.
• Sensing bulb installed in return air flow.
W7459A,C Solid State Economizer Logic Module used with
C7400 Solid State Enthalpy Sensors and M7415 or M8405
Damper Actuators to proportion outdoor and return air dampers for economizer control in commercial HVAC equipment.
• Combine functions of solid state enthalpy changeover
control, minimum damper position potentiometer
(W7459A) and compressor staging relays.
• Optional differential enthalpy control provides greater
economizer savings than single enthalpy control by
selecting the most economical air for cooling.
• W7459A mounts on M7415 Damper Actuator and
accepts inputs from C7150B Mixed Air Sensors, C7400
Solid State Enthalpy Sensors, C7046C Discharge Air
Sensor, and optional remote minimum damper
position potentiometer.
• W7459C mounts on M8405A Damper Actuator and
accepts inputs from single pole single throw (spst)
mixed or discharge air control and C7400 Solid State
Enthalpy Sensors.
• Packages are designed to operate from the cooling
space thermostat to provide a totally integrated control
system.
• Enthalpy setpoint (A,B,C,D) located on W7459 Solid
State Economizer Logic Module is used to select
combination of air temperature and humidity that is
suitable for free cooling.
• W7459A include built-in adjustable minimum damper
position potentiometer that controls the amount of
outdoor air admitted to meet minimum ventilation
requirements; includes terminals for connecting
optional remote minimum position potentiometer.
• LED on W7459 indicates free cooling is available when
there is a call for cooling from the thermostat.
W7212A economizer logic module used with C7400 enthalpy
sensors, M7215 or MS7505 damper actuators and C7232
CO
sensors to proportion outdoor and return air dampers
2
from economizer and demand control ventilation in commercial HVAC equipment.
• Operates from thermostat and DCV sensor to provide a
totally integrated control system.
• Combines minimum and DCV maximum damper
position potentiometers with compressor staging.
• Solid state enthalpy or dry bulb changeover control.
• Terminals included for switching between Occupied
and Unoccupied operation.
• Maximum economizer savings is achieved with two (2)
C7400 enthalpy sensors, one (1) W7212 economizer
logic module, and one (1) C7232 CO
differential enthalpy changeover and Demand Control
Ventilation (DCV).
• LED indicates when free cooling is available.
• LED indicates when module is in DCV mode.
• LED indicates when exhaust fan contact is closed.
• W7213 is used with heat pump B terminal.
• W7214 is used with heat pump O terminal.
sensor using
2
ORDERING INFORMATION
When purchasing replacement and modernization products from your TRADELINE® wholesaler or distributor, refer to the
TRADELINE® Catalog or price sheets for complete ordering number.
If you have additional questions, need further information, or would like to comment on our products or services, please write or
phone:
1. Your local Honeywell Automation and Control Products Sales Office (check white pages of your phone directory).
2. Honeywell Customer Care
1885 Douglas Drive North
Minneapolis, Minnesota 55422-4386
In Canada—Honeywell Limited/Honeywell Limitée, 35 Dynamic Drive, Scarborough, Ontario M1V 4Z9.
International Sales and Service Offices in all principal cities of the world. Manufacturing in Australia, Canada, Finland, France,
Germany, Japan, Mexico, Netherlands, Spain, Taiwan, United Kingdom, U.S.A.
63-2484—22
SOLID STATE ECONOMIZER SYSTEM
MS7505 Spring Return Direct Coupled Actuator
The MS7505 Series Spring Return Direct Coupled Actuators
(DCA) are control actuators that provide proportioning control
for valves and dampers. They accept a voltage signal from an
economizer to position a damper or valve at any chosen point
between fully open and fully closed.
• Control for air damper applications with up to 12.5 sq ft
assuming 3.5 in.-lb per sq ft of damper area, velocity
independent.
• Brushless DC submotor with electronic stall protection.
• Patented self-centering shaft adapter.
• Access cover to facilitate connectivity.
• Metal housing with mechanical end limits.
• Field-installable auxiliary switches.
• Spring return direction field-selectable.
• Hub includes position indicator.
SPECIFICATIONS
IMPORTANT
The specifications given in this publication do not
include normal manufacturing tolerances. Therefore,
these units may not exactly match the specifications
listed. Also, these products are tested and calibrated
under closely controlled conditions and some minor
differences in performance can be expected if these
conditions are changed.
Mounting Arrangement:
Integral mounting flange that requires two no. 8 screws (not
provided).
Maximum Ambient Temperature:
250°F (121°C).
Operating Temperature Range:
40°F to 150°F (4°C to 66°C).
Wiring Connections:
6 in. (152 mm) leadwires.
Dimensions:
See Fig. 1.
C7150B Mixed Air Sensor
Used to sense mixed air in rooftop packaged air conditioning
equipment.
Resistance/Temperature (NTC):
Nominal Resistance: 3000 ohms at 77°F (24°C). Nominal Sen-
sitivity: 70 ohms per degree F (124 ohms per degree C) at
midrange.
Maximum Ambient Temperature:
250°F (121°C).
Operating Temperature Range:
-40°F to +110°F (-40°C to +44°C).
Dimensions:
See Fig. 2.
Models:
Specifications for each model are listed separately.
C7046 Discharge Air Sensors
Intended for use as a discharge sensor in rooftop applications.
Sensing Element:
Carbon type, thermistor-resistor element.
Performance Characteristics:
Reaction Time Constant with Air Approach Velocity of 8.33 ft/
sec (2.54 m/sec): 60 seconds.
Resistance/Temperature (NTC):
Nominal Resistance: 3000 ohms at 77°F (24°C). Nominal Sen-
sitivity: 70 ohms per degree F (124 ohms per degree C) at
midrange.
7/8
(22)
1/4 (6)
DIAMETER
(2)
1-1/2 (38)
3/4 (19)
9/16
(14)
C7400A Solid State Enthalpy Sensor/C7650A Solid
State Temperature Sensor
Senses enthalpy or temperature of outdoor and return air.
Temperature Sensing Element:
Thermistor.
Output Signal:
4 to 20 mA current signal; increases from 4 mA to 20 mA as
enthalpy decreases.
Ambient Operating Temperature Range:
-40°F to +125°F (-40°C to +52°C).
Approval:
Underwriters Laboratories Inc. Flammability Rating: UL94-5V.
Dimensions:
See Fig. 3.
1/2 (13)
DIAMETER
IMMERSION LENGTH: 8 (203)
3/8 (10)
DIAMETER
M9087
Fig. 1. Approximate dimensions of C7046C Air Temperature Sensor in in. (mm).
363-2484—2
SOLID STATE ECONOMIZER SYSTEM
3/4
(19)
Terminal Connections:
1/4 in. (6 mm) male quick connect terminals mounted on actua-
tor. Terminal arrangement is dependent on actuator model.
Ambient Operating Temperature Range:
-40°F to +125°F (-40°C to +52°C).
Voltage and Timing:
See Table 1.
3/16 (5) DIAMETER
2
(51)
2-1/2 (64)
M9084
Fig. 2. Approximate dimensions of C7150B Mixed/
Discharge Air Sensor in in. (mm).
5/16 (8)
3-5/32
(80)
2-3/4
(70)
+
S
Dimensions:
See Fig. 4.
Shaft:
Single-ended drive shaft with crank arm supplied.
Flammability Rating:
Underwriters Laboratories Inc. UL94-5V.
Approval:
Underwriters Laboratories Inc. Component Recognized: File
spring-return damper motor with 2-10 Vdc feedback signal.
Accepts 2-10 Vdc control signal.
Dimensions: See Fig. 4.
Electrical Ratings:
Supply Voltage: 24 ±6 Vac 50/60 Hz.
Power Consumption: 24 Vac, 60 Hz: 8.7 VA. 24 Vac, 50 Hz: 8.4
VA.
Torque:
Lift and Hold: 25 lb-in. (2.8 Nm). Spring Return: 25 lb-in. (2.8
Nm). Breakaway: 40 lb-in. (4.5 Nm).
IMPORTANT
Never use motor continuously at the breakaway
torque rating.
9/16
(14)
1 (25)
7/32
(6)
3-7/8 (96)
M9096
Fig. 3. Approximate dimensions of C7400A Solid State
Enthalpy Sensor/C7650A Solid State Temperature Sensor
in in. (mm).
M7415A, M8405A Damper Actuators
Provides control of economizer systems on HVAC equipment.
Actuator Rotation:
Closed position is the limit of clockwise rotation; open position
is the limit of counterclockwise rotation as viewed from the
shaft end of the motor.
Auxiliary Switch Rating (M8405A only):
24 Vac, 20 VA inrush, 20 VA run.
63-2484—24
NOTE: Breakaway torque available to overcome occasional
large loads such as a seized damper.
Stroke:
Travel: 90°.
Timing:
Driving: 86 ±5 seconds.
Spring Return: 13 ±5 seconds.
Motor Rotation (Viewed From Shaft End):
Closed Position: Limit of clockwise rotation.
Open Position: Limit of counterclockwise rotation.
Crank Arm Rotation Limits: See Fig. 8.
Shipped with shaft in closed position.
Ambient Ratings:
Temperature:
Operating: -25°F to +125°F (-32°C to +52°C).
Storage: -30°F to +150°F (-34°C to +66°C).
Humidity: 5 to 95 percent RH, noncondensing.
Terminal Connections: 1/4 in. (6 mm) quick-connect termi-
nals mounted on motor.
SOLID STATE ECONOMIZER SYSTEM
Shaft: Single-ended drive shaft with crank arm supplied.
A standard spdt switch, without a case, that acts as a
changeover thermostat.
Electrical Rating:
0.25A at 1/.4V to 12 Vdc inductive load.
Control Range, Element Temperature and Differential:
See Table 2.
Approval:
Underwriters Laboratories Inc. Listed:
File E4436, Vol. 4, Guide No. XAPX2.
Dimensions:
See Fig. 5.
563-2484—2
SOLID STATE ECONOMIZER SYSTEM
MOUNTING
HOLES
1
1
ON THE 114496 BRACKET, THE MOUNTING HOLES ARE TWO
NO. 8-32 TAPPED HOLES. THE 107940 BRACKET IS MOUNTED
WITH A 5/32 (4) DIAMETER HOLE AT THE TOP AND A VERTICAL
5/32 X 5/16 (4 X 8) SLOT AT THE BOTTOM.
3/4 (19)
4-3/16
(106)
OVERALL LENGTH: 5 (127)
OVERALL DEPTH LESS
ADJUSTING DIAL SHAFT:
2-1/8 (54)
M9090
Fig. 5. Approximate dimensions of back mounting bracket
for T6031H in in. (mm).
W7459A,C Solid State Economizer Logic Module
Used with C7400 Sensor or C7650A Sensor and M7415 or
M8405 Actuator to proportion outdoor and return air dampers
for economizer control in commercial HVAC equipment.
Electrical Ratings:
Input Voltage: 24 Vac, 50/60 Hz.
Power Consumption: 5.5 VA.
Relay Contact Rating at 24 Vac: 1.5A run, 3.5A inrush.
4074EJM Bag Assembly. Consists of: Checkout jumper, 620
ohm, 1.2K ohm, 5.6K ohm, and 6.8K ohm checkout resistors.
C7046A Discharge Air Temperature Sensor. C7150B Mixed Air
Temperature Sensor.
C7232A,B Carbon Dioxide Sensors.
C7400 Solid State Enthalpy Sensor.
C7650 Dry Bulb Temperature Sensor.
S963B1128 Remote Potentiometer to provide remote control of
damper minimum position.
ST6008 Energy Management Timer for occupied/unoccupied
control.
4-3/8 (112)
1-5/8
(41)
2-1/16
(53)
1-15/16
(49)
4-1/8
(104)
1/8 (4)
2-5/8 (66)
M20578B
Fig. 7. Logic module dimensions in in. (mm).
Table 2. T6031H Thermostat Specifications.
Max Element
Model
Number
Control Range
°F°C°F°C°F°Cftmin.mm
TemperatureDifferential
Type of
Mounting
Capillary LengthBulb Size
T6031H0° to 95°-18° to +35° 150°66°3°2°Back20.63/8 x 3-1/210 x 89
Table 3. W7459A,C,D Specifications.
Model
For Use with
Actuator
Discharge Air
Temperature Input
Minimum Position
Potentiometer Adjustment
Terminals for Remote
Minimum Damper Position
Output
Relays
W7459AM7415Thermistor SensorYesYes2 spdt
W7459CM8405Spst controlNo. Minimum position
No2 spdt
adjustment is built into
M8405 Actuator
W7212AM7215
Thermistor sensorYesYes2 spdt
MS7505
INSTALLATION: M7215, M7415, M8405
4. After installation is complete, check out product operation as provided in these instructions.
When Installing this Product...
1. Read instructions carefully. Failure to follow them could
damage the product or cause a hazardous condition.
2. Check ratings and description given in the specifications
to make sure the product is suitable for your application.
3.
Installer must be a trained, experienced service technician.
CAUTION
Electrical Shock or Equipment Damage Hazard.
Can shock individuals or short equipment circuitry.
Disconnect power supply before installation.
763-2484—2
SOLID STATE ECONOMIZER SYSTEM
CAUTION
Personal Injury Hazard.
Spring-return assembly can release.
Leave end covers attached to the motor.
WIRING: M7215, M7415, M8405
All wiring must comply with applicable codes and ordinances.
Refer to Fig. 9 for typical hookup.
Location and Mounting
Locate motor as close as possible to the equipment to be
controlled. Refer to Fig. 4 for mounting dimensions.
1. Mount motor with the shaft horizontal to ensure maximum life.
NOTE: Operation in other positions is possible when required
by the application.
2. Remove crank arm (secured with two screws) from the
motor hub.
IMPORTANT
Position crank arm on hub so it does not strike motor
mounting surface during any portion of full stroke.
See Fig. 8.
3. Reposition the crank arm to accommodate specific
damper requirements.
NOTE: Crank arm position is adjustable in eight degree
increments.
4. Reconnect crank arm to the motor hub.
5. If there is an excess length of linkage rod, cut it to size.
Make necessary minor adjustments until desired operation is obtained.
6. Tighten all nuts and set screws.
L1
L2
2-10
VDC
CONTROL
METER INDICATING
MOTOR POSITION
(2-10 VDC)
DOTTED LINE REPRESENTS INTERNAL
1
CONNECTIONS OF THE M7215 ACTUATOR.
+
–
TR
TR1
IN+
IN–
OUT
OUT
M7215
1
–
+
M17365
Fig. 9. Typical M7215 wiring.
C7046C Discharge Air Temperature Sensor
The sensor assembly consists of an aluminum sensor probe
(element housed internally) with attached flange that can be
mounted on a flat duct or plenum surface, or in a 2 in. by 4 in.
(51 by 102 mm) junction box, using two no. 8 screws.
Connections to the sensor are made through two 6 in. (152
mm) leadwires.
Location
Locate the sensor in the air duct or plenum where it can
sample average air temperature. Avoid locations where air
stratification can cause sensing errors.
MAXIMUM
OPEN
POSITION
MOTOR MOUNTING SURFACE
CRANK ARM FIELD ADJUSTABLE IN 7.5 DEGREE INCREMENTS.
1
1
MAXIMUM
CLOSED
POSITION
Fig. 8. Limits of crank arm rotation.
M3850
Mounting
To mount the C7046C Sensor on a flat duct or plenum surface
(see Fig. 10):
1. Cut a 1/2 in. (13 mm) hole in the duct or plenum surface
at the desired location.
2. Insert the sensor probe into the duct or plenum hole until
the flange rests against the duct or plenum wall.
3. If necessary, use the flange as a template to mark and
drill two holes for no. 8 mounting screws.
4. Fasten the sensor to the duct or plenum surface with the
two no. 8 sheet metal screws (not provided).
63-2484—28
SOLID STATE ECONOMIZER SYSTEM
To mount the C7046C Sensor in a junction box (see Fig. 11):
1. Cut a 1/2 in. (13 mm) hole in the duct or plenum surface
at the desired location.
2. Remove the center rear knockout from the junction box
and insert the sensor probe through the knockout with
the flange flat against the junction box.
3. Using the flange as a template, mark and drill two holes
in the junction box and the duct or plenum surface for no.
8 mounting screws.
4. Insert the sensor probe through both the junction box
knockout and the 1/2 in. (13 mm) hole drilled in the duct
or plenum and fasten the junction box and sensor to the
duct or plenum surface with the two no. 8 sheet metal
screws (not provided).
SYSTEM DUCT OR PLENUM
FLANGE
SENSOR PROBE
TO APPROPRIATE
SYSTEM COMPONENTS
(SEE WIRING DIAGRAM)
SCREWS NOT PROVIDED.1
SENSOR WIRES WITH
2 SOLDERLESS
CONNECTORS
Fig. 10. Mounting C7046C Air Temperature Sensor on duct
or plenum.
STANDARD 2 X 4 (51 X 102)
OUTLET BOX (OPTIONAL)
NO. 8
MOUNTING
SCREWS (2)
1
M9086
CONNECTOR
AND
LOCKNUT
TO APPROPRIATE
SYSTEM COMPONENTS
(SEE WIRING DIAGRAM)
M9088
SYSTEM DUCT OR PLENUM
Fig. 11. Mounting C7046C Discharge Air Temperature Sensor in junction box.
Wiring
CAUTION
Can Cause Electrical Shock or Equipment Damage.
Disconnect the power supply before connecting the
wiring.
Make sure wiring complies with applicable local codes,
ordinances and regulations.
SENSOR PROBE
FLANGE
BLANK
FACEPLATE
(OPTIONAL)
1
SENSOR WIRES WITH 2
SOLDERLESS CONNECTORS
SCREWS NOT PROVIDED.1
Connect low voltage wiring from the sensor to the appropriate
system component terminals using solderless connectors as
shown in Fig. 10 and 11.
963-2484—2
SOLID STATE ECONOMIZER SYSTEM
IMPORTANT
Failure to follow these wiring practices can introduce
electrical interference (noise) that can cause erratic
system operation:
a. Keep wiring at least one foot away from large induc-
tive loads such as motors, line starters, lighting ballasts, and large power distribution panels.
b. Shielded cable is required in installations where
these guidelines cannot be met.
c. Ground shield only to grounded controller case.
d. Make good physical wiring connections to ensure
good electrical connections.
e. Make sure that building earth ground connections
are not intermittent or missing.
f.Mount sensor only in recommended environment.
MS7505 Damper Actuators
Location and Mounting
LOCATION
Locate the actuator as close as possible to the equipment to
be controlled. Refer to Fig. 12 for mounting dimensions.
Wiring
Disconnect power supply before connecting wiring to prevent
electrical shock or equipment damage. All wiring must comply
with applicable local codes and ordinances.
3-15/16 (100)
1-9/16
(40)
1-9/16
(40)
1-9/16
(40)
2-1/2
(64)
MIN.
3 (76)
MIN.
FROM
SHAFT
END
Dimensions, Approximate 9.72 in. high x 3.94 in. wide x 2.95
in. deep (247 mm high x 100 mm wide x 75 mm deep)
Fail Safe Mode Spring Return
Electrical Connections Enclosed screw terminal strip (22 to
C-Tick N314
Canadian Underwriters Laboratories, Inc. cUL C22.2 No.
24-93
Underwriters Laboratories, Inc. UL873, Plenum Rated
Includes Mounting Bracket, Self-Centering Shaft Adapter,
3mm crank
9-3/4
(247)
6-1/8
(156)
1/4 (6)
3 (76)
MIN.
2-15/16 (75)
M20952
Fig. 12. MS7505 Dimensions Diagram.
63-2484—210
T6031H THERMOSTAT
Location and Mounting
The T6031H Thermostat mounts either vertically or horizontally
on a wall or panel. Locate the remote bulb as far from the
controller as capillary tubing allows.
Mounting Sensing Elements
T6031H: Install the bulb in the return airflow where air of
average temperature can circulate around it.
IMPORTANT
Do not overtighten clamps to the point of distorting
the sensor bulb because overtightening causes a significant shift in bulb calibration.
Mounting Thermostat
Mount the thermostat using the back mounting plate as shown
in Fig. 5.
SOLID STATE ECONOMIZER SYSTEM
Wiring
CAUTION
Can Cause Electrical Shock or Equipment Damage.
Disconnect power supply before connecting wiring.
Disconnect the power supply before connecting wiring to
prevent electrical shock and equipment damage. All wiring
must comply with applicable local codes and ordinances.
Refer to Fig. 13 and the wiring diagrams furnished with the
system equipment to complete the wiring.
TEMPERATURE
RISE
SETPOINT
SWITCH
DIFFERENTIAL
SETPOINT
W
B
R
FOR T6031H
BREAKS R-B;
MAKES R-W
ON RISE
MAKES R-B;
BREAKS R-W
ON FALL
dimensions). Mount device in a location protected from rain,
snow and direct sunlight. Secure device to sheet metal using
the two supplied mounting screws.
CAUTION
Equipment Damage Hazard.
Mounting screws longer than 5/8 in. can damage
internal motor components.
When mounting the module to an M7215 use only the
included #6 5/8 in. thread-forming screw.
M7415, M7405 OR
M8405 ACTUATOR
W7459
ECONOMIZER PACKAGE
M9091
R AND W LOCATIONS
DEPEND ON MODEL
AND CONSTRUCTION
M9089
Fig. 13. T6031H switch terminal arrangement and
switching.
W7459A,C AND W7212 Solid State
Economizer Logic Module
Location and Mounting W7459 Economizer
Logic Module
Mount the W7459 Economizer Logic Module on the side of the
M7415 or M8405 Damper Actuator. When planning the
installation, allow enough clearance for maintenance and
service. Install the W7459 Economizer Logic Module where it
is protected from rain and snow. One mounting screw is
supplied to secure the W7459 to the actuator (after the
actuator is mounted). See Fig. 14.
Location and Mounting W7212
The logic modules mount on an M7215 or a sheet metal duct
or panel. When planning the installation, allow enough
clearance for maintenance and service (see Fig. 15 and 16 for
Fig. 14. Mounting W7459 on M7415 or M8405 Damper
Actuator.
M7215 DAMPER MOTOR
ECONOMIZER
LOGIC MODULE
5/8 INCH SCREW INCLUDED WITH LOGIC MODULE.
M20717B
Fig. 15. Direct mounting of module.
1163-2484—2
SOLID STATE ECONOMIZER SYSTEM
4500
4000
3500
3000
2500
RESISTANCE (OHMS)
2000
1500
3,000 OHMS AT
77F (25C)
M20601
Fig. 16. Mounting the W7212 module on sheet metal.
C7400 Enthalpy Sensor and C7650A
Temperature Sensor Location and Mounting
Outdoor air sensing: Mount the C7400 Enthalpy Sensor or
C7650A Temperature Sensor in any orientation where it is
exposed to freely circulating air but protected from rain, snow
and direct sunlight.
Return air sensing: For differential enthalpy or temperature
control, a second C7400 Enthalpy Sensor or C7650A
Temperature Sensor is connected to the W7459 or W7212.
Mount the second sensor in the return air duct as far as
possible from the outdoor air sensor.
Wiring
CAUTION
Can Cause Electrical Shock or Equipment Damage.
Disconnect power supply before connecting wiring.
Disconnect the power supply before connecting wiring to
prevent electrical shock or equipment damage. All wiring must
comply with applicable local codes, ordinances and
regulations.
OPERATION AND CHECKOUT
1000
6065707580859095100
55
20
15
25
TEMPERATURE (DEGREES)
3035
F
C
M9099
Fig. 17. C7046C and C7150B Air Temperature Sensors
resistance versus temperature.
C7400A Solid State Enthalpy Sensor
The C7400A Solid State Enthalpy Sensor is used with a solid
state economizer control and damper actuator to proportion an
outdoor air damper in a ventilation system.
Figure 18 is a partial psychometric chart with single C7400A
Sensor and W7459A Economizer Logic Module performance
curves. The curves illustrate the reset in the temperature
control point due to changes in relative humidity.
The enthalpy control setpoint A,B,C or D combines
temperature and humidity conditions, resulting in the control
curve shown in Fig. 18. When the enthalpy or outdoor air is
below (left of) the appropriate curve, the outdoor air damper
can proportion open on a call for cooling. If outdoor air enthalpy
rises above (to the right of) the control curve, the outdoor air
damper closes to the minimum position.
For differential enthalpy, turn the control setpoint to D (fully
clockwise). If outdoor air enthalpy is lower than return air enthalpy,
the outdoor air damper proportions open on a call for cooling.
If outdoor air is higher enthalpy than return air enthalpy, the
outdoor air damper closes to minimum position. Differential
enthalpy control provides energy savings and increased
comfort by using the air with the lowest enthalpy.
If outdoor air enthalpy and return air enthalpy are equal, the
outdoor air damper proportions open on a call for cooling.
The relationship between the C7400A Sensor output current
and relative humidity is shown in Fig. 19.
C7046C (Discharge) and C7150B (Mixed) Air Sensors
The C7046C discharge air sensor is applied following the coils
in the supply air to the conditioned space. The C7150B mixed
air sensor is mounted in the mixing box, where the “best”
combination of outdoor and return air temperature can be
measured. Use either a discharge or a mixed air sensor to
provide input to the economizer module through T and T1
Terminals.
63-2484—212
C7650A Solid State Temperature Sensor
The C7650A Solid State Temperature Sensor is used with a
solid state economizer control and damper actuator to
proportion an outdoor air damper in a ventilation system.
When outdoor air temperature is higher than return air
temperature, the outdoor air damper closes to the minimum
position. When the outdoor air temperature and the return air
temperature are equal, the outdoor air damper proportions
open on a call for cooling.
The relationship between the C7650A Sensor output current
and the air temperature is shown in Fig. 20.
85
(29)
SOLID STATE ECONOMIZER SYSTEM
90
95
100
105
(32)
(35)
(38)
(41)
110
(43)
CONTROL
CURVE
12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42
A
B
C
D
CONTROL POINT
APPROX. °F (°C)
AT 50% RH
73 (23)
70 (21)
67 (19)
63 (17)
ENTHALPY—BTU PER POUND DRY AIR
45
(7)
40
(4)
35
(2)
50
(10)
44 46
75
(24)
70
(21)
100
90
55
(13)
60
(16)
B
A
65
(18)
80
C
D
D
70
C
80
(27)
60
RELATIVE HUMIDITY (%)
50
40
30
20
10
1
A
B
35
(2)
40
(4)
45
(7)
50
(10)
55
(13)
60
(16)
65
(18)
70
(21)
75
(24)
80
(27)
85
(29)
90
(32)
95
(35)
100
(38)
105
(41)
110
(43)
APPROXIMATE DRY BULB TEMPERATURE— °F (°C)
1
HIGH LIMIT CURVE FOR W7210D, W7212, W7213, W7214, W7340B.
M11160C
Fig. 18. Partial psychrometric chart with single C7400A Solid State Enthalpy Sensor and W7212 or W7459 Solid State
Economizer Logic Module performance curves.
100
90
80
70
60
50
PERCENT RH
40
30
20
10
(4)(10)(16)(21)(27)(32)(38)
Fig. 19. C7400A Sensor output current vs. relative
C7400A OUTPUT CURRENT
10 mA
12 mA
14 mA
16 mA
18 mA
20 mA
605040708090100
TEMPERATURE F (C)
8 mA
6 mA
4 mA
M9101
19
18
17
mA
14
13
12
11
10
LED ON
D
16
15
LED OFF
9
40
4550 55
NOTE: A,B,C,D ARE W7459 SWITCHING SETPOINTS.
LED ON
LED OFF
6065
C
LED OFF
70 7580 85 90
LED ON
B
LED ON
A
LED OFF
F
100
95
M7578A
Fig. 20. C7650A Solid State Temperature Sensor output
current vs. temperature.
humidity.
1363-2484—2
SOLID STATE ECONOMIZER SYSTEM
M7415 Damper Actuator
Single M7415 Damper Actuator accepts thermistor sensor
input from a C7046A or a C7150B Mixed Air Sensor mounted
in discharge or mixed air duct. See Fig. 27.
During the occupied period, on a call for cooling, when outdoor
air temperature or enthalpy conditions are low, the M7415
Actuator proportions to maintain between 50°F (10°C) and
56°F (13°C) at the thermistor sensor.
If the mixed or discharge temperature is above 56°F (13°C),
the M7415 Actuator opens to admit additional outdoor air until
the temperature returns to the 50°F (10°C) to 56°F (13°C)
range. If the mixed or discharge air temperature is below 50°F
(10°C), the actuator proportions closed, shutting the outdoor
air damper until the temperature returns to the 50°F (10°C) to
56°F (13°C) range. During the occupied period, the actuator
does not close past the minimum position.
If the fully open M7415 Actuator cannot satisfy the space
demand, mechanical cooling is sequenced on.
During the unoccupied period, the M7415 Actuator overrides
the minimum position setting and drives fully closed. On a loss
of power, the actuator spring-returns fully closed.
If terminals P and P1 are jumpered, the M7415 drives fully
open; however, if terminals P and P1 are left open, the M7415
drives fully closed. The M7415 minimum position adjustment
drives the motor open when the resistance across P and P1 is
minimal. Increasing the amount of resistance across these
terminals drives the actuator closed.
The economizer functions as a true first stage of cooling and
provides maximum fuel economy during the cooling cycle. The
economizer is automatically locked out during heating. It holds
the outdoor air damper at the minimum position setting. On a
call for cooling by the space thermostat, the system operates
as follows:
When the enthalpy or temperature of the outdoor air is below
the setpoint, the outdoor air damper is proportioned open (and
the return air damper is proportioned closed) to maintain
between 50°F and 56°F (10°C and 13°C) at the mixed/
discharge air sensor. During economizer operation, the
mechanical cooling is operated by stage 2 cooling on the
space thermostat.
When the enthalpy or temperature of the outdoor air is above
the setpoint, the outdoor air damper closes to its minimum
position. A call for cooling from the space thermostat turns on
the mechanical cooling.
During the unoccupied period, the M7415 Damper Actuator
spring-returns the outdoor air damper to the fully closed
position.
W7212A Economizer Logic Module
W7212A economizer logic module used with C7400 enthalpy
sensors, M7215 or MS7505 damper actuators and C7232 CO
sensors to proportion outdoor and return air dampers from
economizer and demand control ventilation in commercial
HVAC equipment.
W7212A Optional Applications
2
M8405 Damper Actuator
An spst low-voltage controller is used to control the M8405
Actuator as follows:
a. Fully open—when the controller circuit closes to pro-
vide 24 Vac to terminals D and T, the actuator is
energized and runs fully open.
b. Fully closed—when the controller circuit opens,
power is removed from terminals D and T, and the
actuator spring-returns to the fully closed position.
c. Mid-position—when the controller circuit closes to
provide 24 Vac to terminals T and X, the actuator is
energized to run to the adjustable mid-position (mini-
mum position).
Adjustable minimum position can be reached from either the
fully closed or fully open position. From fully closed, the
actuator drives open to the minimum position; from fully open,
the actuator spring-returns to minimum position.
W7459A,C Solid State Economizer Logic
Module
The purpose of an economizer is to use outdoor air for cooling
whenever possible, to reduce air conditioner compressor
operation. The W7459 Economizer System, when wired as
shown in Fig. 27, responds to a signal from the cooling
thermostat. This system uses a C7400 Enthalpy Sensor or a
C7650A Temperature Sensor. It responds to both dry bulb
temperature and humidity, allowing the use of outdoor air at
higher temperatures for free cooling when the humidity is low.
HEAT PUMP CHANGEOVER (W7213, W7214 ONLY)
In heat pump applications, the controller must have control of
the changeover valve. To provide the logic module with the
information necessary for proper information, there must be a
connection to the logic module O/B terminal. This terminal
alerts the logic module as to when the system operates in
cooling (the only time the economizer is used).
W7213 (CHANGEOVER TERMINAL B)
Connect the B terminal according to the following details:
— 24V power to B: System is in heating mode.
— No power to B: System is in cooling mode.
W7214 (CHANGEOVER TERMINAL O)
Connect the O terminal according to the following details:
— 24V power to O: System is in cooling mode.
— No power to O: System is in heating mode.
SETTINGS AND ADJUSTMENTS
Adjusting Minimum Damper Position
The minimum position potentiometer keeps the outdoor air
damper from completely closing during system operation to
allow ventilation.
63-2484—214
SOLID STATE ECONOMIZER SYSTEM
M7415 and M8405 Damper Actuators
Adjusting Minimum Position (Ventilation)
The M7415 Damper Actuator is adjusted for desired minimum
position using a Q709 Actuator Mounted Minimum Position
Potentiometer and/or a remote S963B1136 Manual
Potentiometer. The M8405 Damper Actuator has an integral
thumbwheel for minimum position adjustment.
M7415 Minimum Position Adjustment
1. Run actuator to fully closed position and disconnect 24
Vac from terminals TR and TR1.
2. Connect minimum position potentiometer to terminals P
and P1 (T and T1 are disconnected).
3. Reconnect 24 Vac to terminals TR and TR1 and adjust
the potentiometer for the desired minimum position.
4. When the Q709 Actuator Mounted Minimum Position
Potentiometer is used and a remote potentiometer is not
connected in series, jumper terminals P and P1 on the
Q709A.
M8405 Minimum Position Adjustment
1. Connect the 24 Vac to the actuator at terminals T and X
(D is not connected).
2. Adjust the thumbwheel on the actuator for desired
minimum position.
Discharge Air Temperature Setpoint
Adjustment—M7415 Only
This temperature range can be adjusted either up or down by
wiring a resistor in series (to increase the setpoint) or in parallel
(to decrease the setpoint) with the C7150B, depending on the
application. See Fig. 21 and 22 for explanation.
W7459A,C Solid State Economizer Logic
Module
Two potentiometers with small screwdriver slots for adjustment
are located on the face of the module.
Minimum Position Adjustment
W7459A ECONOMIZER LOGIC MODULE
1. Make sure the factory-installed jumper is in place
across terminals P and P1 (terminals T and T1 are
disconnected.
2. Connect 24 Vac at terminals TR and TR1 and adjust the
potentiometer on the face of the W7459A with a small
screwdriver for desired minimum position.
W7459C ECONOMIZER LOGIC MODULE
1.
Connect 24 Vac at terminals TR and X (D is not connected).
2.
Adjust thumbwheel on motor for desired minimum position.
Enthalpy Changeover Setpoint
Single enthalpy: the enthalpy changeover setpoint is set to
return the outdoor air damper to the minimum position when
the enthalpy rises above its setpoint. The enthalpy setpoint
scale markings, located on the W7459, are A, B, C, D; see Fig.
18 for the corresponding control point. The factory-installed
620-ohm jumper must be in place across terminals + and S
ENTHALPY
CHANGEOVER
SETPOINT
.
R
R
C7150
RESISTOR VALUE (OHMS)
USE 1%, 1/8 W OR HIGHER RESISTOR
681
2760
3650
4420
4750
4870
NO RESISTOR
T
T1
M7415
C7150B SETPOINT °F (°C)
54.5—61.5 (12.5—16.4)
68.4—80.1 (20.3—26.8)
87.4—110.3 (30.8—45.5)
104.7—150 (40.4—65.5)
116—194 (46.7—90)
120—300 (49—149)
50—56 (10—13.3)
Fig. 21. Increasing C7150B setpoint.
T
R
C7150
RESISTOR VALUE (OHMS)
USE 1%, 1/8 W OR HIGHER RESISTOR
18.2K
24K
30K
NO RESISTOR
T1
M7415
C7150B SETPOINT °F (°C)
36—44 (2.2—6.7)
39.5—47 (4.0—8.3)
42—49 (5.6—9.4)
50—56 (10—13.3)
Fig. 22. Decreasing C7150B setpoint.
M1544C
M1545C
MINIMUM
DAMPER
POSITION
1
SETTING
LED LIGHTS
WHEN OUTDOOR
AIR IS SUITABLE
FOR FREE COOLING
MINIMUM DAMPER POSITION ADJUSTMENT
1
IS PRESENT ONLY ON W7459A,D MODELS.
M9098B
Fig. 23. Location of enthalpy setpoint potentiometer,
minimum position potentiometer and LED.
Differential Enthalpy Changeover Setting
(USE THIS OPTION ONLY WITH TWO-STAGE COOLING
THERMOSTATS.)
Differential enthalpy control uses two C7400 Enthalpy Sensors
or two C7650A Temperature Sensors connected to one W7459
Solid State Economizer Logic Module.
1563-2484—2
SOLID STATE ECONOMIZER SYSTEM
The setpoint scale markings, located on the W7459, are A,B,C
and D. Turn the setpoint potentiometer fully clockwise to the D
setting. The economizer selects the air that has lower enthalpy
or temperature for cooling; for example, if outdoor air has lower
enthalpy or temperature than return air, the outdoor air damper
is opened to bring in outdoor air for free cooling.
Remote Minimum Position Control
Remote control of outdoor air dampers is desirable when
requiring temporary additional ventilation. The addition of a
S963B1128 Remote Potentiometer allows occupants to open
or close the dampers beyond minimum position for modified
ventilation.
SEQUENCE OF OPERATION
Economizer Sequence of Operation
(WITH AND WITHOUT DIFFERENTIAL ENTHALPY)
The economizer operating sequence for both the modulating
and the three-position control systems are identical when the
outdoor enthalpy temperature is above the mixed air setpoint
of 55°F (13°C). The operating sequence for both, using a
standard two-stage thermostat is:
1. The first stage of the thermostat signals a need for
cooling.
2. The W7459 Solid State Economizer Logic Module
begins to make decisions regarding the unit/
economizer operation.
3.
a. On the standard (non-differential) economizers, the
logic module checks the outdoor air C7400 Enthalpy
Sensor or C7650 Temperature Sensor to determine if
the enthalpy or temperature is below the setpoint.
b. On the differential economizers, the logic module
checks to determine if the outdoor air temperature is
below the return air temperature.
4. If the logic module uses the outside air for cooling, the
mixed air sensor prevents the entering air from going
below 50°F (10°C).
a. On the modulating system, the control closes the
outside air damper and opens the return air damper
to mix the outside air and return air to maintain 50°–
55°F (10°–13°C).
b. On the three-position system, the mixed air sensor
switch opens, closing the fresh air damper until the
mixed air sensor temperature returns above 55°F
(13°C), closing the switch and re-opening the outside
air damper.
5.
a. If the logic module senses that the outside air is not
suitable for cooling, the air conditioning unit compressor is energized and the space is cooled with
refrigerated air.
b. On the two-stage thermostat, the economizer is the
first stage if the outside air temperature is suitable for
cooling. The compressor on the unit is energized if
the second stage of the thermostat is energized,
thereby creating an integrated economizer.
6. Refer to Table 4 for further information on outside air
damper positions.
Table 4. Outdoor air damper positions.
Outside
Tem per atur e
Standard Economizer Damper Position
1
Modulating
2
3-Position
2
Temperature
Return
Differential Enthalpy Damper Position
1
Modulating
2,3
3-Position
80ClosedClosed80ClosedClosed
85OpenOpen
75ClosedClosed75ClosedClosed
80OpenOpen
70OpenOpen75OpenOpen
65OpenOpen
60OpenOpen75OpenOpen
55OpenOpen75OpenOpen
54 and downModulatingOpening/Closing75ModulatingOpening/Closing
1
Standard economizer position based on enthalpy control set on the A setting and 50% relative humidity.
2
Closed position is either the minimum position or fully closed, depending on the job setting.
3
Opening/closing is dependent on the mixed air temperature.
2,3
63-2484—216
SOLID STATE ECONOMIZER SYSTEM
OPERATION: W7212
The purpose of the economizer is to use outdoor air for
cooling, whenever possible, to reduce compressor operation.
Power at the N terminal determines the Occupied/Unoccupied
setting:
— W7212:
• 24 Vac (Occupied).
• No power (Unoccupied).
— W7213,W7214:
• W7213 (CHANGEOVER TERMINAL B)
— 24V power to B: System is in heating mode.
— No power to B: System is in cooling mode.
• W7214 (CHANGEOVER TERMINAL O)
— 24V power to O: System is in cooling mode.
— No power to O: System is in heating mode.
NOTE: When module is operating in Occupied mode, the
minimum position is defined by the potentiometer.
When the module is operating in Unoccupied mode,
and there is no call for cooling, the damper drives fully
closed.
When wired as shown in Fig. 28–33, the logic module
responds to the cooling thermostat signal. The system uses
C7400 Solid State Enthalpy Changeover Sensor(s) or C7650
Dry Bulb Temperature Sensor(s). The C7400 responds to both
dry bulb temperature and humidity, allowing use of outdoor air
at higher temperatures for free cooling when humidity is low.
The C7650 responds only to dry bulb temperature; use only in
dry, arid climates.
The logic module functions as a true first stage of cooling
providing maximum energy economy during the cooling cycle.
It automatically locks out free cooling during heating; holding
the outdoor air damper at the minimum position setting.
The logic module can operate as either a basic free cooling
controller, or it can incorporate additional functions. Table 5
details the input/output (I/O) logic of the module.
S963B1128 REMOTE
POTENTIOMETER
P
MINIMUM
POSITION
ADJUSTMENT
CW
M20603A
CW
CLOSE
W
R
B
P1
ECONOMIZER
Fig. 24. S963B1128 Remote Potentiometer used with logic
module for remote damper control.
Table 5. W7212 Economizer I/O Logic.
INPUTSOUTPUTS
Demand Control
Ventilation (DCV)
Below set (DCV
LED Off)
Enthalpy
OutdoorReturnStage 1 Stage 2
High (Free
Cooling LED Off)
a
CompressorN Terminal
Y1Y2
LowOnOnOnOnMinimum positionClosed
OnOffOnOff
Occupied
b
Damper
b
Unoccupied
b
OffOffOffOff
Low (Free
Cooling LED On)
HighOnOnOnOff
OnOffOffOff
Modulating
min. position and full-
c
(between
Modulatingc (between
closed and full-open)
open)
OffOffOffOffMinimum positionClosed
Above set (DCV
LED On)
High (Free
Cooling LED Off)
Low (Free
Cooling LED On)
Low OnOnOnOn
OnOffOnOff
OffOffOffOff
HighOnOnOnOff
OnOffOffOff
Modulating
min. position and DCV
maximum)
Modulating
d
(between
e
Modulatingd (between
closed and DCV
maximum)
Modulating
f
OffOffOffOff
a
For single enthalpy control, the module compares outdoor enthalpy to the ABCD setpoint.
b
Power at N terminal determines Occupied/Unoccupied setting:
• W7212: 24 Vac (Occupied), no power (Unoccupied).
• W7213,W7214: No power (Occupied), 24 Vac (Unoccupied).
c
Modulation is based on the mixed air sensor signal.
d
Modulation is based on the DCV signal.
e
Modulation is based on the greater of DCV and mixed air sensor signals, between minimum position and either maximum position (DCV) or fully open (mixed air signal).
f
Modulation is based on the greater of DCV and mixed air sensor signals, between closed and either maximum position (DCV) or
fully open (mixed air signal).
1763-2484—2
SOLID STATE ECONOMIZER SYSTEM
NOTES:
—DCV and Free Cooling have setpoints and LED indications.
—For models with a B terminal (W7213):
No power to B: cooling mode, free cool enabled. Module follows logic detailed above.
24V power to B: heating mode, free cool disabled. Actuator drives to minimum position (closed when Unoccupied).
—For models with an O terminal (W7214):
24V power to O: cooling mode, free cool enabled. Module follows logic detailed above.
No power to O: heating mode, free cool disabled. Actuator drives to minimum position (closed when Unoccupied).
SETTINGS AND ADJUSTMENTS: W7212
CAUTION
Equipment Damage Hazard.
Excessive force can damage potentiometer
controls.
Use a small screwdriver when adjusting enthalpy
changeover and minimum damper position controls.
Potentiometers with small screwdriver adjustment slots,
located on device face, provide adjustments for several
parameters (see Fig. 25 for locations on device):
limit the amount of outdoor air flow into the building when the
DCV overrides the mixed air sensor and allows the proper
ventilation based on occupancy. Setting the DCV maximum
position of the damper prevents the introduction of large
amounts of hot or cold air into the space by preventing the
dampers from opening 100%. Set the DCV maximum position
at the maximum design occupancy.
IMPORTANT
With the DCV maximum position set below the minimum position, the minimum position overrides the
maximum position (negating most DCV functions of
the logic module, as the damper cannot move).
NOTES:
—When the mixed air sensor takes control based on
an increased requirement for cooling, it overrides
the DCV maximum position potentiometer and can
drive the damper full-open.
—If the mixed air temperature drops to 45°F, the
mixed air sensor overrides the DCV and fully
closes the damper to protect from freezing the hot
or chilled water coils. Control returns to normal
once the mixed air temperature rises to 48°F.
Minimum Position Adjustment
For detailed assistance in minimum position selection
reference the Economizer Application Guide (form 63-8594)
Ventilation section. The following provides basic guidelines for
minimum position selection and adjustment:
IMPORTANT
• Adjust the minimum position potentiometer to allow
the minimum amount of outdoor air for building effluents, as required by local codes, to enter the building.
• This procedure requires use of a quality thermometer
capable of reading to 0.5°F (0.25°C).
NOTE: Make minimum position adjustments with at least a
10°F (6°C) temperature difference between outdoor
and return air.
Fig. 25. Potentiometer and LED locations (W7212 shown).
Demand Control Ventilation Setpoint
The logic module modulates the outdoor damper to provide
ventilation based on the 0/2-10 Vdc DCV. With no cooling
signal, the DCV overrides the outdoor air damper when
ventilation requires additional outdoor air.
Adjusting Minimum and Maximum Positions
The minimum position potentiometer maintains the minimum
outdoor air flow into the building during the occupied period.
The minimum position allows for the building effluents. The
DCV maximum position potentiometer allows the installer to
63-2484—218
1. Calculate the appropriate mixed air temperature. See
Equation 1.
2. Disconnect mixed air sensor from terminals T and T1.
3. Place a jumper across terminals T and T1.
4. Ensure that either the factory-installed jumper is in place
across terminals P and P1 or, if remote damper position
is required, that it is wired according to Fig. 24 and
turned fully clockwise.
5. Connect 24 Vac across terminals TR and TR1.
6. Carefully adjust the potentiometer on the face of the
device with a small screwdriver until the mixed air temperature reaches the calculated value.
NOTE: Ensure that the sensed air is well-mixed.
SOLID STATE ECONOMIZER SYSTEM
7. If all minimum and maximum position adjustments are
complete, remove the T-T1 jumper and reconnect the
mixed air sensor.
EQUATION 1. FORMULA TO AID MINIMUM POSITION ADJUSTMENT.
(T
× OA)+(TR × RA)= T
O
M
Where:
T
= Outdoor air temperature
O
OA = Percent of outdoor air
T
= Return air temperature
R
RA = Percent of return air
TM = Resulting mixed air temperature
NOTE: The following sample calculation uses only Fahren-
heit temperature.
EXAMPLE: Assume local codes require 10% outdoor air dur-
ing occupied conditions, outdoor air is 60°F and
return air is 75°F. Under these conditions, what is
the temperature of the mixed air?
(0.1 × 60°F)+(0.9 × 75°F)=6.0°F + 67.5°F=73.5°F
Mixed air will be 73.5°F when OA is 60°F and RA is 75°F with
10 percent outdoor air entering the building.
DCV Maximum Position Adjustment
1. Disconnect mixed air sensor from terminals T and T1
and short terminals T and T1.
2. Connect a jumper between terminals AQ and AQ1.
3. Connect 24 Vac across terminals TR and TR1.
4. Adjust the potentiometer on the face of the device with a
small screwdriver for desired maximum position.
5. If all minimum and maximum position adjustments are
complete, remove the T-T1 jumper and reconnect the
mixed air sensor.
Enthalpy Changeover Setpoint
NOTE: Turn the enthalpy setpoint potentiometer fully clock-
wise to the D setting.
The logic module selects the lower enthalpy air (return or
outdoor) for cooling. For example, when outdoor air has lower
enthalpy than return air, the module calls to open the outdoor
air damper to bring in outdoor air for free cooling.
Exhaust Setpoint
The exhaust setpoint determines when the exhaust fan runs
based on damper position. When the exhaust fan call is made,
the module provides a 60 ±30 second delay before exhaust fan
activation. This delay allows the damper to reach the
appropriate position to avoid unnecessary fan overload.
NOTES:
—EF and EF1 are 24V dry contacts only. An external
line voltage contactor is required to operate the
exhaust fan.
—When the exhaust fan is deactivated the EF and
EF1 contacts open immediately.
CHECKOUT AND TROUBLESHOOTING
Tables 6 through 10 provide step-by-step economizer checkout
and troubleshooting steps. See Fig. 23 and 25 for enthalpy
setpoint potentiometer, minimum position potentiometer and
LED locations.
The outdoor enthalpy changeover setpoint returns the outdoor
air damper to minimum position when enthalpy rises above its
setpoint. Enthalpy setpoint scale markings, located in the
device, are A, B, C and D. See Fig. 18 for the corresponding
control point. The factory-installed 620-ohm jumper must be in
place across terminals SR and SR+. Temperature and humidity
points to the left of the selected curve will allow the dampers to
open for free cooling.
Differential Enthalpy Changeover Setting
Differential enthalpy control uses two C7400 Enthalpy Sensors
connected to one logic module. The logic module compares
outdoor air to return air.
1963-2484—2
LED LIGHTS WHEN
OUTDOOR AIR IS SUITABLE
FOR FREE COOLING
INSERT DC MILLIAMMETER BETWEEN SO AND S FOR CHECKOUT
1
AND TROUBLESHOOTING.
2
JUMPER USED FOR SINGLE ENTHALPY CONTROL.
M9097
Fig. 26. Meter location for checkout and troubleshooting.
SOLID STATE ECONOMIZER SYSTEM
M8405
T
APPLY
24VAC T-X
FOR MIN POSN
T-D FOR
MAX POSN
X
D
W7459C ECONOMIZER PACKAGE
M8405 ACTUATOR
T
MAX
SW
SET
MIN
C7400
OUTDOOR
SENSOR
+
TRTR1
S
O
+
S
S
+
C7400
RETURN
SENSOR
S
+
UNOCCUPIED
OCCUPIED
T675/T6031 MIXED
AIR CONTROL
55¡ F SETPOINT
ST6008
TIMER
W
R
R
1
3
6
5
5
1K
2
4
X
D
4
2K
X
D
C
Y1
Y2
W2
W
T6031 AMBIENT
R
LOCKOUT CONTROL
50¡ F SETPOINT
Y1
Y2
W2
COOL 1
COOL 2
HEAT 2
2
HEAT 1
FAN
DELAY
RELAY
FAN
1
3
L2
L1
(HOT)
M3865B
6
T7300 OR T874
THERMOSTAT
W1
W1
X
G
RH
RC
HVAC EQUIPMENT
TERMINAL STRIP
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
1
2
MOTOR SPRING-RETURNS CLOSED WHEN FAN IS NOT RUNNING.
3
ENSURE THAT EQUIPMENT TRANSFORMER IS SIZED TO HANDLE THE EXTRA LOAD OF THE ECONOMIZER AND ACTUATOR.
4
RELAYS 1K AND 2K ACTUATE WHEN THE ENTHALPY SENSED BY THE C7400 IS HIGHER THAN THE ENTHALPY SETPOINT A-D.
5
FACTORY INSTALLED 620 OHM, 1 WATT, 5% RESISTOR SHOULD BE REMOVED ONLY IF A C7400 ENTHALPY SENSOR
IS ADDED TO SR AND + FOR DIFFERENTIAL ENTHALPY.
6
FOR T7300 ONLY.
FDR
G
FDR
R
Fig. 27. M8405A Damper Actuator used in two-stage cooling system with differential enthalpy changeover and W7459C
Economizer.
63-2484—220
UNOCCUPIED
8
ST6008
TIMER
C7400
OUTDOOR
AIR
ENTHALPY
SENSOR
620 OHM
RESISTOR
C7150B MIXED
AIR OR
C7046A
DISCHARGE
AIR SENSOR
SOLID STATE ECONOMIZER SYSTEM
M7415 ACTUATORW7459A ECONOMIZER PACKAGE
TR
24 VAC
TRTR1
+
+
S
S
6
O
S
+
R
5
1K
1
2
4
3
T
T1
P
P1
5
2K
MINIMUM POSITION
ADJUSTMENT
1S
4
1S1
TR1
T
T1
P1
P
MIXED
AIR
SENSOR
MINIMUM
POSITION
7
OCCUPIED
C
2
COOL 1
COOL 2
HEAT 2
HEAT 1
FAN
DELAY
RELAY
FAN
24 VAC
SENSOR
MIN
POS
1
3
L2
L1
(HOT)
Y1
Y2
W2
W1
W2
W1
Y1
Y2
W
T6031 AMBIENT
LOCKOUT
R
CONTROL
50 F SETPOINT
G
X
RH
RC
T7300 OR T874
THERMOSTAT
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2
MOTOR SPRING-RETURNS CLOSED WHEN FAN IS NOT RUNNING.
3
ENSURE THAT EQUIPMENT TRANSFORMER IS SIZED TO HANDLE THE EXTRA LOAD OF THE ECONOMIZER AND ACTUATOR.
4
1S IS AN ELECTRONIC SWITCH THAT CLOSES WHEN POWERED BY A 24 VAC INPUT.
5
RELAYS 1K AND 2K ACTUATE WHEN THE ENTHALPY SENSED BY THE C7400 IS HIGHER THAN THE ENTHALPY SETPOINT A-D.
6
FACTORY INSTALLED 620 OHM, 1 WATT, 5% RESISTOR SHOULD BE REMOVED ONLY IF A C7400 ENTHALPY SENSOR
IS ADDED TO SR AND + FOR DIFFERENTIAL ENTHALPY.
7
FOR T7300 ONLY.
8
WITH T7300, USE CONTACTS A1 AND A2 INSTEAD OF S7005 TIMER.
HVAC EQUIPMENT
TERMINAL STRIP
FDR
G
FDR
R
M7415
TR
TR1
T
T1
P1
P
M10115A
Fig. 28. W7459A/C7400 used in two-stage cooling system with single enthalpy changeover and with M7415 Actuator.
2163-2484—2
SOLID STATE ECONOMIZER SYSTEM
C7150B MIXED
AIR OR C7046A
DISCHARGE
AIR SENSOR
0/2-10 VDC
INDOOR AIR
SENSOR
C7400
OUTDOOR
AIR
ENTHALPY
SENSOR
+
S
–
+
3
620 OHM
RESISTOR
AQ1
SO+
SR+
TR1
HOT
TR
24 Vac
24
COM
Vac
– +
24 VAC HOT
24 VAC COM
2-10 VDC CONTROL
SIGNAL INPUT
2 1
5
4
3
EF
EF1
M7215
5
L1
(HOT)
L2
EXHAUST
FAN
N1
N
P1
P
T1
T
AQ
SO
SR
MINIMUM POSITION
ADJUSTMENT
W7212
Y1
Y2
W2
W1
A2
A1
RH
4
G
C
Y1
Y2
W2
W1
A2
A1
G
COOL 1
COOL 2
HEAT 2
HEAT 1
FAN
RC
X
T7300/Q7300
THERMOSTAT
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2
ENSURE THAT TRANSFORMER IS SIZED TO HANDLE THE EXTRA LOAD OF THE ECONOMIZER AND ACTUATOR. USE THE SAME
TRANSFORMER FOR T7300 AND ECONOMIZER.
3
FACTORY INSTALLED 620 OHM, 1 WATT, 5% RESISTOR SHOULD NOT BE REMOVED. DIFFERENTIAL ENTHALPY NOT RECOMMENDED FOR USE
WITH SINGLE-STAGE COOLING SYSTEMS OR SINGLE-STAGE COOLING THERMOSTATS.
4
T7300 TERMINALS A1 AND A2 ARE CONNECTED WHEN THERMOSTAT IS IN THE OCCUPIED MODE.
EF AND EF1 ARE DRY CONTACTS IN THE LOGIC MODULE.
5
R
HVAC EQUIPMENT
TERMINAL STRIP
Fig. 29. W7212 used with M7215 Damper Motor and T7300 Thermostat.
2
L2
L1
(HOT)
M20716D
1
63-2484—222
C7400
OUTDOOR
AIR
ENTHALPY
SENSOR
+
S
C7150B MIXED
AIR OR C7046A
DISCHARGE
AIR SENSOR
0/2-10 VDC
INDOOR AIR
SENSOR
SOLID STATE ECONOMIZER SYSTEM
TR1
HOT
TR
24 Vac
24
COM
Vac
– +
24 VAC HOT
24 VAC COM
2-10 VDC CONTROL
SIGNAL INPUT
2 1
5
4
3
EF
EF1
M7215
5
L1
(HOT)
L2
EXHAUST
FAN
N1
N
P1
P
T1
T
–
+
AQ1
SO+
SR+
AQ
SO
SR
4
620 OHM
RESISTOR
MINIMUM POSITION
ADJUSTMENT
W7212
Y1
Y2
W2
W1
AUX
G
3
C
Y1
Y2
W2
W1
A2
COOL 1
COOL 2
HEAT 2
HEAT 1
RH
G
FAN
RC
X
T7350
THERMOSTAT
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2
ENSURE THAT TRANSFORMER IS SIZED TO HANDLE THE EXTRA LOAD OF THE ECONOMIZER AND ACTUATOR.
THE SAME TRANSFORMER CAN BE USED FOR THE THERMOSTAT AND ACTUATOR.
IF SEPARATE HEATING AND COOLING TRANSFORMERS ARE USED, REMOVE JUMPER AT THERMOSTAT.
3
T7350 - TERMINAL “AUX” IS POWERED BY THE HEATING TRANSFORMER (RH).
IF POWERING THE ECONOMIZER TERMINAL “N” WITH THE THERMOSTAT TERMINAL “AUX”, BE SURE THE ECONOMIZER IS POWERED BY THE
SAME TRANSFORMER AS TERMINAL “AUX”. IF NOT, USE AN ISOLATION RELAY TO POWER “N”.
4
FACTORY INSTALLED 620 OHM, 1 WATT, 5% RESISTOR SHOULD NOT BE REMOVED. DIFFERENTIAL ENTHALPY NOT RECOMMENDED FOR USE
WITH SINGLE-STAGE COOLING SYSTEMS OR SINGLE-STAGE COOLING THERMOSTATS.
EF AND EF1 ARE DRY CONTACTS IN THE LOGIC MODULE.
5
R
HVAC EQUIPMENT
TERMINAL STRIP
2
L2
L1
(HOT)
M13657
1
Fig. 30. W7212 used with M7215 Damper Motor and T7350 Thermostat.
2363-2484—2
SOLID STATE ECONOMIZER SYSTEM
C7150B MIXED
AIR OR C7046A
DISCHARGE
AIR SENSOR
0/2-10 VDC
INDOOR AIR
SENSOR
C7400
OUTDOOR
AIR
ENTHALPY
SENSOR
+
S
–
+
4
620 OHM
RESISTOR
AQ1
SO+
SR+
TR1
HOT
TR
24
24 Vac
Vac
COM
– +
24 VAC HOT
24 VAC COM
2-10 VDC CONTROL
SIGNAL INPUT
2 1
5
4
3
EF
EF1
M7215
5
L1
(HOT)
L2
EXHAUST
FAN
N1
N
P1
P
T1
T
AQ
SO
SR
MINIMUM POSITION
ADJUSTMENT
W7212
Y1
Y2
W2
W1
3
A
G
C
Y1
Y2
W2
W1
A
COOL 1
COOL 2
HEAT 2
HEAT 1
R
G
FAN
RC
X
TB7220 OR TB8220
THERMOSTAT
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2
ENSURE THAT TRANSFORMER IS SIZED TO HANDLE THE EXTRA LOAD OF THE ECONOMIZER AND ACTUATOR.
THE SAME TRANSFORMER CAN BE USED FOR THE THERMOSTAT AND ACTUATOR.
IF SEPARATE HEATING AND COOLING TRANSFORMERS ARE USED, REMOVE JUMPER AT THERMOSTAT.
3
TB7220 - TERMINAL “A” IS POWERED BY THE COOLING TRANSFORMER (RC).
TB8220 - TERMINAL “A” IS POWERED BY THE HEATING TRANSFORMER (R).
IF POWERING THE ECONOMIZER TERMINAL “N” WITH THE THERMOSTAT TERMINAL “A”, BE SURE THE ECONOMIZER IS POWERED BY THE
SAME TRANSFORMER AS TERMINAL “A”. IF NOT, USE AN ISOLATION RELAY TO POWER “N”.
4
FACTORY INSTALLED 620 OHM, 1 WATT, 5% RESISTOR SHOULD NOT BE REMOVED. DIFFERENTIAL ENTHALPY NOT RECOMMENDED FOR USE
WITH SINGLE-STAGE COOLING SYSTEMS OR SINGLE-STAGE COOLING THERMOSTATS.
5
EF AND EF1 ARE DRY CONTACTS IN THE LOGIC MODULE.
R
HVAC EQUIPMENT
TERMINAL STRIP
2
L2
L1
(HOT)
M13658
1
Fig. 31. W7212 used with M7215 Damper Motor and TB7220 or TB8220 Thermostats.
63-2484—224
F
MS7XXX
HONEYWELL
ACTUATOR
C7400
OUTDOOR
AIR
ENTHALPY
SENSOR
SOLID STATE ECONOMIZER SYSTEM
TR1
HOT
TR
24 Vac
24
COM
Vac
– +
2 1
5
4
3
EF1
EF
4
N1
~
1
2
3
+
4
5
C7150B MIXED
AIR OR C7046A
DISCHARGE
AIR SENSOR
0/2-10 VDC
INDOOR AIR
SENSOR
–
+
3
+
N
P1
P
T1
T
AQ1
AQ
SO+
SO
SR+
SR
620 OHM
RESISTOR
MINIMUM POSITION
ADJUSTMENT
W7212
S
C
L1
Y1
Y1
COOL 1
Y2
5
W2
W1
W2
W1
G
RH
RC
X
THERMOSTAT
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2
ENSURE THAT TRANSFORMER IS SIZED TO HANDLE THE EXTRA LOAD OF THE ECONOMIZER AND ACTUATOR.
3
FACTORY INSTALLED 620 OHM, 1 WATT, 5% RESISTOR SHOULD NOT BE REMOVED. DIFFERENTIAL ENTHALPY NOT RECOMMENDED FOR USE
WITH SINGLE-STAGE COOLING SYSTEMS OR SINGLE-STAGE COOLING THERMOSTATS.
4
EF AND EF1 ARE DRY CONTACTS IN THE LOGIC MODULE.
5
SEE WIRING DIAGRAMS FOR T7350 AND TB7220/TB8220.
TIME CLOCK IS AN OPTION TO USING OCCUPIED CONTACTS ON THE THERMOSTAT.
6
HVAC EQUIPMENT
TERMINAL STRIP
FDR
G
FDR
R
HEAT 2
HEAT 1
FAN
DELAY
RELAY
FAN
ST6008
TIMER
(HOT)
L2
EXHAUST
FAN
UNOCCUPIED
OCCUPIED
2
L2
1
L1
(HOT)
M24219
6
Fig. 32. W7212A used in single-stage cooling system with single enthalpy changeover and Honeywell actuator and time
clock for occupancy.
2563-2484—2
SOLID STATE ECONOMIZER SYSTEM
~
1
2
3
+
4
F
5
MS7XXX
HONEYWELL
ACTUATOR
C7400
OUTDOOR
AIR
ENTHALPY
SENSOR
Y1
Y2
W2
8
W1
G
RH
RC
4
X
T7300 OR T874
THERMOSTAT
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
2
ENSURE THAT TRANSFORMER IS SIZED TO HANDLE THE EXTRA
LOAD OF THE ECONOMIZER AND ACTUATOR.
3
1S IS AN ELECTRONIC SWITCH THAT CLOSES WHEN POWERED
BY A 24 VAC INPUT.
4
FOR T7300 ONLY
5
FACTORY INSTALLED 620 OHM, 1 WATT, 5% RESISTOR SHOULD BE
REMOVED ONLY WHEN A C7400 ENTHALPY SENSOR IS ADDED TO
SR AND SR+ FOR DIFFERENTIAL ENTHALPY.
+
S
C7150B MIXED
AIR OR C7046A
DISCHARGE
AIR SENSOR
0/2-10 VDC
INDOOR AIR
SENSOR
T6031 AMBIENT
W
LOCKOUT
CONTROL
R
50 F SETPOINT
–
+
5
620 OHM
RESISTOR
AQ1
SO+
SR+
TR1
N1
N
P1
P
T1
T
AQ
SO
SR
MINIMUM POSITION
ADJUSTMENT
1S
3
1S1
W7212
TR
24 Vac
24
COM
Vac
HOT
– +
1K
2K
2 1
5
4
3
EF1
EF
7
C
L1
Y1
Y2
W2
W1
FDR
G
COOL 1
COOL 2
HEAT 2
HEAT 1
FAN
DELAY
RELAY
FAN
6
ST6008
TIMER
FDR
R
HVAC EQUIPMENT
TERMINAL STRIP
6
USE THE FOLLOWING CONTACTS INSTEAD OF TIMER
FOR T7300, USE A1 AND A2 TERMINALS.
FOR T7350 USE AUX TERMINAL.
FOR TB7220 OR TB8220 USE A TERMINAL
THE TERMINALS ARE CONNECTED WHEN THERMOSTAT IS IN THE OCCUPIED MODE.
7
EF AND EF1 ARE DRY CONTACTS IN THE LOGIC MODULE.
8
SEE WIRING DIAGRAMS FOR T7350 AND TB7220/TB8220.
TIME CLOCK IS AN OPTION TO USING OCCUPIED CONTACTS ON THE THERMOSTAT.
9
(HOT)
L2
EXHAUST
FAN
UNOCCUPIED
OCCUPIED
2
L2
1
L1
(HOT)
M24220
9
Fig. 33. W7212A used in two-stage cooling system with Honeywell Series 72 Actuator and time clock for occupancy.
63-2484—226
1
2
(HOT)
L2
L1
(HOT)
1
L1
L2
3
ST6008
TIMER
~
+
F
MS7XXX
HONEYWELL
ACTUATOR
~
+
F
MS7XXX
HONEYWELL
ACTUATOR
UNOCCUPIED
OCCUPIED
SOLID STATE ECONOMIZER SYSTEM
1
2
3
4
5
C7150B MIXED
AIR OR C7046A
DISCHARGE
AIR SENSOR
N1
N
P1
P
T1
T
MINIMUM POSITION
ADJUSTMENT
1
2
3
4
0/2-10 VDC
INDOOR AIR
SENSOR
–
+
5
C7400
OUTDOOR
7
AIR
ENTHALPY
SENSOR
+
S
4
620 OHM
RESISTOR
AQ1
SO+
SR+
AQ
SO
SR
W7212
C
HOT
TR1
TR
24 Vac
24
COM
Vac
– +
2 1
5
4
3
EF1
EF
5
COOL 1
COOL 2
HEAT 2
HEAT 1
FAN
DELAY
RELAY
FAN
EXHAUST
FAN
L2
L1
(HOT)
1
L1
(HOT)
L2
M24221
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
2
ENSURE THAT TRANSFORMER IS SIZED TO HANDLE
THE LOAD OF ALL ACTUATORS.
USE THE FOLLOWING CONTACTS INSTEAD OF TIMER
3
FOR T7300, USE A1 AND A2 TERMINALS.
FOR T7350 USE AUX TERMINAL.
FOR TB7220 OR TB8220 USE A TERMINAL
THE TERMINALS ARE CONNECTED WHEN THERMOSTAT
IS IN THE OCCUPIED MODE.
FACTORY INSTALLED 620 OHM, 1 WATT, 5% RESISTOR
4
SHOULD BE REMOVED ONLY WHEN A C7400 ENTHALPY
SENSOR IS ADDED TO SR AND SR+ FOR DIFFERENTIAL
ENTHALPY.
EF AND EF1 ARE DRY CONTACTS IN THE
5
LOGIC MODULE.
6
SEE WIRING DIAGRAMS FOR T7350
AND TB7220/TB8220.
7
TIME CLOCK IS AN OPTION TO USING OCCUPIED CONTACTS
ON THE THERMOSTAT.
Y1
Y2
W2
W1
G
RH
RC
X
THERMOSTAT
6
Y1
Y2
W2
W1
FDR
G
FDR
R
HVAC EQUIPMENT
TERMINAL STRIP
Fig. 34. W7212 controlling parallel-wired Honeywell Series 72 Actuators and time clock for occupancy.
2763-2484—2
SOLID STATE ECONOMIZER SYSTEM
~
1
2
3
+
4
F
5
MS7XXX
HONEYWELL
ACTUATOR
C7400
OUTDOOR
AIR
ENTHALPY
SENSOR
C7150B
DISCHARGE
AIR SENSOR
0/2-10 VDC
INDOOR AIR
SENSOR
+
S
–
+
5
3
O
N
P1
P
T1
T
AQ1
AQ
SO+
SO
SR+
SR
620 OHM
RESISTOR
MINIMUM POSITION
ADJUSTMENT
W7214
HOT
TR1
TR
24 Vac
24
COM
Vac
– +
2 1
4
5
3
EF1
EF
2
A3
4
A2
Y1
Y2
W2
W1
G
RH
RC
C
Y1
Y2
W2
W1
COOL 1
COOL 2
HEAT 2
HEAT 1
G
FAN
L2
R
L1
(HOT)
X
O O
T7300
THERMOSTAT
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2
EF AND EF1 ARE DRY CONTACTS IN THE LOGIC MODULE.
3
FACTORY INSTALLED 620 OHM, 1 WATT, 5% RESISTOR SHOULD BE REMOVED ONLY WHEN A
C7400 ENTHALPY SENSOR IS ADDED TO SR AND SR+ FOR DIFFERENTIAL ENTHALPY.
4
T7300 TERMINALS A2 AND A3 ARE CONNECTED WHEN THERMOSTAT IS IN THE UNOCCUPIED MODE.
SEE WIRING DIAGRAMS FOR T7350 AND TB7220/TB8220.
Condition on Logic Module Should BeCondition Not Met
1. Red LED not lighted.1. If the LED glows, the Logic Module recognizes conditions are good for free cool-
ing. Verify that conditions are above the enthalpy setpoint, see Note 2. Check wiring to Enthalpy Control for a short from {SO} and {+}.
2. 24 Vac to terminals {TR} and {TR1}.2. Check the wiring from [G] and [C] on the unit low voltage terminal strip. {TR} and
{TR1} power the actuator.
3. 24 Vac to terminals {1} and {TR1}.3. Verify that there is a call for cooling from the thermostat. Without a call for cooling,
the compressor can not be in the normal air conditioning mode.
4. 24 Vac to terminals {2} and {TR1}.4. If 24 Vac is not on {2} and {TR1}, the internal switch is not set correctly. Remove
the {SO} wire from the module. If 24 Vac is on {2} and {TR1}, the enthalpy control
is bad or the {SO} and {+} wires are shorted together. If no voltage to {2} and
{TR1}, the module is bad.
5. Continuity on terminals {1} and {2}, {3}
and {4}.
5. If there is not continuity for terminals {1} and {2}, the internal switch is not in the
correct position and the module is defective. If there is continuity from terminals
{1} and {2}, the red LED should not be lighted. If there is continuity on terminals
{3} and {4}, the internal switch is correctly energized. The damper actuator should
be in a min. position.
6. Compressor does not operate with all
above conditions correct.
6. Check the wiring from {2} to Y1 on the unit low voltage control board. If the LED is
not lighted, check 24 Vac from {2} to Y1.
Second Stage
7. 24 Vac to terminals {3} and {TR1}.7. Verify that you have a two-stage thermostat. Check for a call for a second stage
cooling. If 24 Vac is not on {3} and {TR1}, check wiring from Y2 on the thermostat
to the module.
8. 24 Vac to terminals {4} and {TR1}.8. If {4} and {TR1} do not have 24 Vac, and {3} and {TR1} have 24 Vac, the internal
switch is not in the correct position. The module is defective.
9. Compressor does not operate with
second stage conditions met.
9. If all other functions are correct, check wiring from {4} to Y2 on the unit low voltage
terminal board.
Condition on Logic Module Should BeConditions Not Met
1. Red LED lighted.1. Jumper terminals {SO} and {+}. If the LED lights, the module is okay, see Note 2.
Check wiring to enthalpy control.
2. 24 Vac to terminals {TR} and {TR1}.2. Check the wiring from [G] and [C] on the unit low voltage terminal strip. {TR} and
{TR1} power the actuator.
3. 24 Vac to terminals {1} and {TR1}.3. Verify there is a call for cooling from the thermostat. Without a call for cooling, the
motor can not be in the economizer mode.
4. No continuity on terminals {1} and {2}. 4. If there is continuity from terminals {1} and {2}, the red LED should not be lighted. If
there is continuity and the LED glows, the module is defective.
5. Continuity on terminals {3} and {5}.5. If there is continuity on terminals {3} and {5}, the internal switch is correctly energized. Damper motor should be in a modulating mode.
6. Motor does not operate with all above
conditions met.
6. Jumper the mixed air sensor terminals {T} and {T1}. If the motor begins to operate,
check the wiring to the sensor. If correct, the temperature is below the sensor setpoint or it is defective. If the motor does not operate, and the wiring is correct and
the temperature is above the sensor setpoint, the motor is bad.
Second Stage
7. 24 Vac to terminals {3} and {TR1}.7. Verify that you have a two-stage thermostat. Check for a call for a second stage
cooling. If 24 Vac is not on terminals {3} and {TR1}, check wiring from terminal Y2
on the thermostat to the module.
8. 24 Vac to terminals {5} and {TR1}.8. If terminals {5} and {TR1} do not have 24 Vac, the internal switch is not in the cor-
rect position, assuming that terminals {3} and {TR1} have 24 Vac. The module is
defective.
9. Compressor does not operate with
second stage conditions met.
9. If all other functions are correct, check the wiring from terminal {5} to Y2 on the unit
low voltage terminal board.
Condition on Logic Module Should BeConditions Not Met
1. Red LED not lighted.1. If the LED glows, the module is in the economizer mode. Verify the conditions are
above the enthalpy setpoint, see Note 2. Check wiring to Enthalpy Control for a
short from {SO} and {+}.
2. 24 Vac to terminals {TR} and {TR1},
{X} and {TR}.
2. Check the wiring from [G] and [C] on the unit low voltage terminal strip. {TR} and
{TR1} power the actuator. {X} and {TR} provide power for minimum position.
3. 24 Vac to terminals {1} and {TR}.3. Verify that there is a call for cooling from the thermostat. Without a call for cooling
the compressor can not be in the normal air conditioning mode.
4. 24 Vac to terminals {2} and {TR}.4. If 24 Vac is not on {2} and {TR}, the internal contacts are not set correctly. Remove
the {SO} wire from the module. If 24 Vac is on {2} and {TR}, the enthalpy control is
bad or the {SO} and + wiring are shorted together. If no voltage to {2} and {TR}, the
module is bad.
5. Continuity on terminals {1} and {2}, {3}
and {4}.
5. If there is not continuity for {1} to {2}, the internal contacts are not in the correct
position, and either the module or the enthalpy control is defective. If there is continuity from terminals {1} and {2}, the red LED should not be lighted. If there is continuity and the LED glows, the module is defective. If there is continuity on terminals
{3} and {4}, the internal contacts are correctly energized. Damper motor should be
in the min. position.
6. Compressor does not operate with all
above conditions correct.
6. Check the wiring from {2} to Y1 on the unit low voltage control board. Verify that
there are not 24 Vac to Y1 and C on the unit.
Second Stage
7. 24 Vac to terminals {3} and {TR}.7. Verify that the thermostat is two-stage. Check for a call for a second stage cooling.
If there are not 24 Vac on {3} and {TR}, check wiring from Y2 on the thermostat to
the module.
8. 24 Vac to terminals {5} and {TR}.8. If {5} and {TR} do not have 24 Vac and {3} and {TR} have 24 Vac, the internal
switch 1S is not in the correct position. The module is defective.
9. Compressor does not operate with
second stage conditions met.
9. If all other functions are correct, check the wiring from {5} to Y2 on the unit low voltage terminal board.
Table 9. Troubleshooting three position economizer—outdoor enthalpy below setpoint.
Condition on Logic Module Should BeConditions Not Met
1. Red LED lighted.1. Jumper terminals {SO} and {+}. If the LED glows, the module is okay, see Note 2.
Check wiring to enthalpy control.
2. 24 Vac to terminals {TR} and {TR1}.2. Check the wiring from [G] and [C] on the unit low voltage terminal strip. {TR} and
{TR1} power the actuator.
3. 24 Vac to terminals {1} and {TR1}.3. Verify there is a call for cooling from the thermostat. Without a call for cooling, the
motor can not be in the economizer mode.
4. No continuity on terminals {1} and {2}. 4. If there is continuity from terminals {1} and {2}, then the red LED cannot be lighted.
If there is continuity and the LED glows, the module is defective.
5. Continuity on terminals {3} and {5}.
5. If there is continuity on terminals {3} and {5}, the internal switch 1S is correctly
energized. Damper motor should be in a modulating mode.
6. Motor does not operate with all above
conditions met.
6. Jumper the mixed air sensor terminals {6} and {D}. If the motor begins to operate,
check the wiring to the sensor. If it is correct, the temperature is below the sensor
setpoint or the sensor is defective. If the motor does not operate, the wiring is correct, and the temperature is above the sensor setpoint, the motor is bad.
Second Stage
7. 24 Vac to terminals {3} and {TR}.7. Verify that the thermostat is two-stage. Check for a call for a second stage cooling.
If 24 Vac is not on {3} and {TR}, check wiring from Y2 on the thermostat to the
module.
8. 24 Vac to terminals {5} and {TR}.8. If {5} and {TR} do not have 24 Vac, and {3} and {TR} do have 24 Vac, then the
internal switch 1S is not in the correct position. The module is defective.
9. Compressor does not operate with
second stage conditions met.
9. If all other functions are correct, check the wiring from {5} to Y2 on the unit low voltage terminal board.
63-2484—230
SOLID STATE ECONOMIZER SYSTEM
CHECKOUT AND TROUBLESHOOTING:
W7212
Checkout requires a 9V battery, 620 ohm, 1.2K ohm, 5.6K
ohm, and 6.8K ohm resistors. Use Table 10 and Fig. 36 for
checkout.
CAUTION
Equipment Damage Hazard.
Excessive force can damage potentiometer
controls.
Use a small screwdriver when adjusting enthalpy
changeover and minimum damper position controls.
Table 10. Checkout for W7212, W7213, W7214 Economizers Connected to Honeywell Actuator.
W7212
Free
Cool
EXH
DCV
EXH
Set
10V
2V
Min
Pos
Open
DCV
Max
10V
2V
DCV
Set
2V
10V
B
C
A
D
M20612
N1
N
P1
P
1
DC VOLTMETER
+
–
S
C7400
+
1
INSERT DC VOLTMETER BETWEEN AQ AND AQ1 FOR
CHECKOUT AND TROUBLESHOOTING.
2
JUMPER USED FOR SINGLE ENTHALPY CONTROL.
T1
T
AQ1
AQ
SO+
SO
SR+
SR
2
620 OHM RESISTOR
Fig. 36. Meter location for checkout and troubleshooting
(W7212 shown).
StepCheckout ProcedureProper Response
1.CHECKOUT PREPARATION
Disconnect power at TR and TR1.All LED are off; Exhaust Fan contacts are open.
Disconnect devices at P and P1.
Jumper P to P1.
Place 5.6K ohm resistor across T and T1.
Jumper TR to 1.
W7212 only: Jumper TR to N.
If connected, remove C7400 Enthalpy Sensor from
terminals S
and +.
O
Connect 1.2K ohm 4074EJM Checkout Resistor across
terminals S
Put 620 ohm resistor across S
and +.
O
and +.
R
Set minimum position, DCV setpoint, and Exhaust
potentiometers fully CCW.
Turn DCV maximum position potentiometer fully CW.
Set enthalpy potentiometer to D.
Apply power (24 Vac) to terminals TR and TR1.
2.DIFFERENTIAL ENTHALPY
Execute step one, Checkout Preparation.–
Place 620 ohm resistor across S
Place 1.2K ohm resistor across S
and +.–
O
and +.Free cool LED turns on.
R
Remove 620 ohm resistor from SO and +.Free cool LED turns off.
3.SINGLE ENTHALPY
Execute step one, Checkout Preparation.–
Set enthalpy potentiometer to A (fully CCW).Free cool LED turns on.
Set enthalpy potentiometer to D (fully CW).Free cool LED turns off.
3163-2484—2
SOLID STATE ECONOMIZER SYSTEM
Table 10. Checkout for W7212, W7213, W7214 Economizers Connected to Honeywell Actuator. (Continued)
StepCheckout ProcedureProper Response
4.DCV AND EXHAUST
Execute step one, Checkout Preparation.–
Ensure terminals AQ and AQ1 are open.LED for both DCV and Exhaust should be off.
Actuator drives fully closed.
Connect 9V battery positive to AQ and negative to AQ1.LED for both DCV and Exhaust turn on.
Actuator drives to between 81 and 85 degrees open.
Turn Exhaust potentiometer CW until Exhaust LED turns
off.
Exhaust LED turns off with potentiometer approximately 90
percent CW. Actuator remains in position.
Turn DCV setpoint potentiometer CW.DCV LED turns off with potentiometer at approximately 9V.
Actuator drives fully closed.
Turn DCV setpoint potentiometer CCW until Exhaust LED
turns on.
Exhaust contacts close 30-90 seconds after Exhaust LED
turns on.
Turn DCV setpoint potentiometer CW.Exhaust LED turns off with potentiometer indication at
approximately 9V.
Turn Exhaust potentiometer CCW until Exhaust LED turns
on.
Exhaust contacts close 30-90 seconds after Exhaust LED
turns on.
5.MINIMUM AND MAXIMUM POSITION
Execute step one, Checkout Preparation.–
Connect 9V battery positive to AQ and negative to AQ1.DCV LED turns on. Actuator drives to between 81 and 85
degrees open.
Turn DCV maximum position potentiometer to midpoint.Actuator drives to between 18 and 72 degrees open.
Turn DCV maximum position potentiometer to fully CCW.Actuator drives fully closed.
Turn minimum position potentiometer to midpoint.Actuator drives to between 18 and 72 degrees open.
Turn minimum position potentiometer fully CW.Actuator drives fully open.
W7212: Remove jumper from TR and N.Actuator drives fully closed.
6.MIXED AIR INPUT
Execute step one, Checkout Preparation.–
Set enthalpy potentiometer to A.Free cool LED turns on.
Actuator drives to between 18 and 72 degrees open.
Remove 5.6K ohm resistor and jumper from T and T1.Actuator drives fully open.
Remove jumper from T and T1 and leave open.Actuator drives fully closed.
7.HEAT PUMP INPUT - W7213, W7214 ONLY
Execute step one, Checkout Preparation.–
Set enthalpy potentiometer to A.Free cool LED turns on.
Actuator drives to between 18 and 72 degrees open.
W7213: Jumper TR to B.
W7214: Remove jumper from TR and O.
Free cool LED turns off.
Actuator drives fully closed
Automation and Control Solutions
Honeywell International Inc.Honeywell Limited-Honeywell Limitée