LENNOX Economizer Energence Rooftop Units Instruction Manual

LENNOX Economizer Energence Rooftop Units

INSTALLATION INSTRUCTIONS FOR ECONOMIZERS AND OUTDOOR AIR HOODS USED WITH

LG/LC/LH/LD 024, 036, 048, 060, 072, 074 UNITS

Note
Disregard economizer installation section when dampers are factory install.

Package 1 of 1 contains

• 1 Economizer damper assembly1.
• 1 GED2 gravity exhaust / barometric relief damper.
• 1 Combination hood kit containing.
• 1 Hood top filter bracket.
• 2 Hood sides1-Bag containing screws.
• 1 Pivot bracket.

Bag assembly containing

• 1 J18 harness
• 1 Harness instruction
• 1 Already in place when economizer is factory installed.
• 2 GED is shipped and ordered separately for factory PEF units.
• 3 Shipped in the return air section when economizer is factory-installed.
• 4 Shipped in the blower section when economizer is factory-installed.
• 5 The divider panel is shipped and ordered with the GED for factory PEF units.

Package 1 of 1 ordered separately contains

• Used in horizontal airflow applications only
• 1 Return air cover

Order Of Installation

• Return air cover horizontal airflow
• Economizer
• Mixed air sensor R1
• Remove GED horizontal airflow and PEF options Optional OA/RA sensors
• Power exhaust fans
• GED seal in unit PEF option
• GED in lower hood (horizontal and PEF options) RA Transition (horizontal airflow)
• RA duct horizontal airflow
• Lower outdoor air hood
• Upper outdoor air hood

WARNING
Improper installation, adjustment, alteration, service or maintenance can cause property damage, person­al injury or loss of life. Installation and service must be performed by a licensed professional HVAC in­staller or equivalent, service agency, or the gas sup­plier.

CAUTION
As with any mechanical equipment, contact with sharp sheet metal edges can result in personal injury. Take care while handling this equipment and wear gloves and protective clothing.

Application

The economizer is used with LG/LC/LH/LD units in downflow and horizontal air discharge applications. For horizontal air applications, use the separately shipped GEDH kit. See table 1. See table 2 for the optional gravity exhaust kit. The economizer uses outdoor air for free cooling when temperature and/or humidity is suitable. LG/LC/LH/LD units are equipped with the following factory-installed, CEC Title 24 approved sensors:

• RT17 – Outside Air Temperature
• Return Air Temperature
• RT6 – Discharge Air Temperature

Optional field provided sensors may be used instead of unit sensors to determine whether outdoor air is suitable for free cooling.

WARNING

To prevent serious injury or death:

1. Lock-out/tag-out before performing maintenance.
2. If system power is required (e.g., smoke detector mainte­nance, disable power to blower, remove fan belt where applicable, and ensure all controllers and thermostats are set to the OFF position before performing maintenance.
3. Always keep hands, hair, clothing, jewelry, tools, etc., away from moving parts.

Gravity Exhaust Kit

Install  Economizer – Downflow

Install Economizer  Downflow

• Open unit end panel and filter access panel. See figure
• When gravity or power exhaust are field-installed, remove and discard the lower panel.
• Remove and retain sensors from mounting bracket.
• Remove mounting bracket and discard.
• Remove hood top from economizer outdoor air opening and hood divider panel from economizer exhaust air opening.
• Install damper assembly by inserting the damper motor first.
• Fit opening in bottom of damper assembly over the return air opening.
• Install retained sensors in the side of the economizer.
• Connect economizer plug P4 to unit jack J3 hanging near the top of the filter.
• Optional Power and Gravity Exhaust.
• Locate J18 and J24 connectors bundled with J3.
• Insert connectors in openings J18 Harness.

Note
If J18 harness isn’t hanging near the top of the filter access area, use the J18 harness provided with the filter kit. Follow instructions in the J18 harness bag assembly. If J18 is hanging near the top of the filter area AND J18 is installed in the side of the economizer, remove J18 from the side of the economizer. Insert J18 hanging near the top of the filter area.

UNIT

REMOVE SENSORS AND BRACKET

INSERT DAMPER MOTOR FIRST (TOP VIEW)

ECONOMIZER INSTALLATION

GED (Barometric Relief Dampers)

For horizontal airflow applications, a separately shipped GEDH gravity exhaust damper kit is required.

CONNECT ECONOMIZER PLUG P4 TO UNIT JACK J3

Optional PEF

Factory lnstalled PEF Only

• Remove the PEF cover over the exhaust air opening before installing.
• A GED kit is packaged separately and shipped with the unit.
• Remove GED from the economizer and install in the fresh/ exhaust air hood when optional power exhaust fans are installed.
• Install the power exhaust fans and GED seal in the unit.
• Instal the outdoor/exhaust air hood. Install the GED in the low.
• Let hood Soo fiquro 9

REMOVE GED DOVWNFLOW WITH PEF

INSTALL PIVOTING BRACKET AND GED SEAL

FIELD-INSTALLED ECONOMIZERS ONLY

For factory-installed econo­mizer the pivot bracket is al­ready installed. For field-in­stalled economizers the piv­ot bracket is in the filter kit.

Outdoor Air Hoods Downflow

Factory Installed Economizers Only

The hood top and pivot bracket is installed over the unit fresh (outdoor) air opening. The hood divider panel is secured over the unit exhaust air opening. Hood sides and top filter bracket are located in the return air section. Lift hood top and divider panel and assemble hoods as described for field-installed economizers.

• Make sure all sensors and outdoor air section accessories are installed before installing hoods.
• Install pivot bracket.
• Assemble hood.
• Slide top of hood into the ends of pivot bracket.
• Install top filter bracket after filter is in place.
• Install hoods on unit.
• Caulk ends of pivot bracket to seal watertight.

Install Economizer Horizontal

A field-fabricated return air duct transition and duct inlet must be installed in horizontal applications.

• Remove unit end panel.
• Install the downflow return air cover in horizontal airflow applications.
• Secure with #10 sheet metal screws provided in kit.
• Make sure the horizontal return air cover on the back side of the unit remains in place.
• The opening is used when an economizer is not installed.
• Install the economizer and R1 mixed air sensor and connect wiring.
• Install the field-fabricated return air duct transition and duct inlet on the unit end.
• Support the transition and duct inlet as needed.
• Install the lower (exhaust) hood on the return air duct as shown in the GEDH kit instruction.
• Install the upper hood on the unit.

UNIT

ASSEMBLE HOODS DOWNFLOW AIR APPLICATIONS

HORIZONTAL AIRFLOW

HORIZONTAL GEDH OUTDOOR AIR HOOD

TYPICAL HORIZONTAL APPLICATION

Economizer Start Up  M2 Unit Controller

The unit will be equipped with either an M2, M3, or M4 Unit Controller. M2, M3, or M4 will be printed on the bottom of the Unit Controller near the SBUS connector or seven-segment display. Use the appropriate start-up section in this manual and refer to the Unit Controller provided with the rooftop unit. Application available for both Unit Controllers. The economizer is controlled by the Unit Controller which is located in the unit control panel. A detailed menu layout can be found in the Unit Controller manual provided with each unit.

A Field Installed Economizer

The Unit Controller must be set to identify an economizer has been installed. Use the Unit Controller keypad to enter the following menu Setting / Install / Damper.10- Use the up/down arrows to display ECON and press the SELECT button SET will display.Press the left arrow returning up the menu path until the Unit Controller resets and saves the change. The Unit Controller will now operate the economizer.

B-Free Cooling Mode and Setpoint

On start-up, the economizer mode defaults to TEMP OFFSET. In this mode, free cooling is energized when the outdoor air temperature (RT17) is less than return air temperature (RT16) by at least the offset value. The default offset value is 10°F. Use the following menu path on the Unit Controller to adjust the free cooling mode or setpoint

Settings / Setpoints / Damper / Economizer Mode

The Unit Controller has a restricted range of input values for each mode.

Note
An energy management system may be used to provide the outdoor air suitable (OAS) signal via network connection. The free cooling mode must be set to one of the TEMP modes to allow this function.

Economizer Start Up M2 Unit Controller

The unit will be equipped with either an M2, M3, or M4 Unit Controller. M2, M3, or M4 will be printed on the bottom of the Unit Controller near the SBUS connector or seven-segment display. Use the appropriate start-up section in this manual and refer to the Unit Controller provided with the rooftop unit. Application manuals are available for both Unit Controllers. The economizer is controlled by the Unit Controller which is located in the unit control panel. A detailed menu layout can be found in the Unit Controller manual provided with each unit.

A Field Installed Economizer

The Unit Controller must be set to identify an economizer has been installed. Use the Unit Controller keypad to enter the following menu

Setting/ Install / Damper

Use the up/down arrows to display ECON and press the SELECT button SET  will display. Press the left arrow returning up the menu path until the Unit Controller resets and saves the change. The Unit Controller will now operate the economizer.

B Free Cooling Mode and Setpoint

On start-up, the economizer mode defaults to TEMP OFF SET. In this mode, free cooling is energized when the outdoor air temperature (RT17) is less than return air temperature (RT16) by at least the offset value. The default offset value is 10°F. Use the following menu path on the Unit Controller to adjust the free cooling mode or setpoint. Settings/ Setpoints / Damper / Economizer for additional free cooling modes and setpoints. The Unit Controller has a restricted range of input values for each mode.

Note
An energy management system may be used to provide the outdoor air suitable (OAS) signal via network connection. The free cooling mode must be set to one of the TEMP modes to allow this function.

C-California Title 24

Compliance For California Title 24 compliance, adjust the free cooling setpoint based on.

• The climate zone where the unit is installed.
• The setpoint requirement published by the California Energy Commission.
• Prescriptive Requirements for Space Conditioning Systems of the 2013 Building Energy Efficiency Standards.

Note
Values in the referenced standard will supersede values.

SENSOR LOCATION

ECONOMIZER MODES AND SETPOINT

Free Cooling Mode| Free Cooling Setpoint| Field- Provided Sensors| Dampers will modulate to 55°F discharge air RT6 when outdoor air is suitable| Permitted Inputs
---|---|---|---|---
TEMP| OFFSET| None Needed| Outdoor air temperature RT17 is less than return air temperature (RT16) by at least the OFFSET value.| 0-40°F
TEMP| OAT STPT| None Needed| Outdoor air temperature RT17 is less than the OAT STPT value.| 41-75°F

Remote

|

Remote

| Energy Management System**| Either of the TEMP modes can be used when a network OAS signal is provided by an energy management or building control system, via BACnet, LonTalk, or L Con­ nection. The network can command OAS, NOT OAS, or AUTO. AUTO returns to local control of OAS, which is the selected TEMP mode.|

NA

ENTH| DIFF OFFSET| Two C7400| Outdoor air enthalpy* (A7) is less than return air enthalpy A62 by at least the OFF­ SET value.| 0mA-4mA
ENTH| ODE STPT| C7400| Outdoor air enthalpy (A7) is less than free cooling setpoint.| 12-19mA

GLOBAL

|

GLOBAL

|

24VAC Input Signal

| Global input is energized by P297-9. This setting is also used for outdoor air damp­ er applications. Global input also brings on the blower. This mode is NOT used when OAS signal is provided via network connection. GLO is only used when a 24VAC signal is used to energize the P297-9 GLO input.|

NA

Enthalpy includes effects of both temperature and humidity. Energy management systems may require additional field provided sensors.

FREE COOLING SETPOINT

Climate Zone| Setpoint

Single S0ensible

| Setpoint

Differentia0l  Sensible

---|---|---
1, 3, 5, 11-16| 750F| 00F
2, 4, 10| 730F| 20F
6, 8, 9| 710F| 40F
7| 69 F| 6 F

Setting Free Cooling Setpoint in Enthalpy Mode

Free Cooling Setpoint ODE STPT

The enthalpy sensor A7 provides a milliamp signal to the Unit Controller based on outdoor air temperature and humidity. To set a free cooling setpoint of 73°F at 50% relative humidity, enter 12 at the ODE STPT menu prompt. The Unit Controller will allow dampers to modulate open at approximately 73°F. If the space temperature is too warm, change the ODE STPT to 13.6 and the Unit Controller will allow dampers to modulate open at approximately 70°F.

FREE COOLING SETPOINT ODE STPT MODE

Free Cooling Differential Enthalpy DIFF OFFSET

The Unit Controller allows damper modulation when outdoor air is lower than return air by a differential or offset temperature and humidity range. To set an offset range of 7°F at a constant relative humidity, enter 4″ at the DIFF OFFSET menu prompt. If return air is 76°F, the Unit Controller will allow damper to modulate open at approximately 69° F outdoor air. See table 6. If the space temperature is too cool or dry, change the DIFF OFFSET to 3″ and the Unit Controller will allow dampers to modulate open at approximately 71°E outdoor air.

FREE COOLING SETPOINT DIFF OFFSET MODE

*Temperat­ ure

Offset °F

| **Relative Hu­ midity Offset %| Menu Entry mA|

Counts

---|---|---|---
2| 6| 1| 13
3.5| 12| 2| 26
5.3| 18| 3| 39
7| 24| 4| 53

At a constant relative humidity. At a constant temperature.

Damper Minimum Position Setting

Use the menu path in figure 13 to set the minimum % open damper position when outdoor air is not suitable for free cooling. The minimum setpoint range is 0% open dampers closed to 100% dampers fully open. On units equipped with a ventilation control board, refer to the VCB Start-Up section in the installation instructions provided with each unit.

FREE COOLING OPTIONS

Config. ID1 POS 2| Unit Controller Input Mode| M3 Display

Free Cooling Options

| Default Setting| Range Setting|

Outdoor air is suitable for free cooling when:

---|---|---|---|---|---

T

| Differential Sensible Sensor (default mode)| ECONOMIZER TEMP ECON TYPE = TEMPERATURE OFFSET|

10°F

|

0°F – 40°F

|

Outdoor air temperature (RT17) is less than return air temperature (RT16) by at least the offset value.

T

|

Single Sensible Sensor

| ECONOMIZER TEMP ECON TYPE = TEMPERATURE SETPOINT|

75°F

|

40 F – 75 F

|

Outdoor air temperature (RT17) is less than the Out­ door Air Temperature set point value.

T

|

Network OAS

|

ECONOMIZER TEMP ECON TYPE = TEMPER­ ATURE OFFSET or SETPOINT

|

Not Applicable

|

Not Applicable

| Either of the TEMP modes (set point or offset) can be used when a network OAS signal is provided by an energy management or building control system, via BACnet, LonTalk, or L Connection. The network can command OAS, NOT OAS, or AUTO. AUTO returns to local control of OAS, which is the selected TEMP mode.

S

| Single Enthalpy* Sensor| ECONOMIZER ENTHALPY SETPOINT =

12.0 MA

|

12.0 mA

|

10mA – 19 mA

| Outdoor air enthalpy (A7) is less than enthalpy set point parameter.

D

| Differential En­ thalpy* Sensor| ECONOMIZER ENTHALPY OFFSET =

1.0 MA

|

1.0 mA

|

1 mA – 5 mA

| Outdoor air enthalpy* (A7) is less than return air enthal­ py (A62) by at least the OFFSET value.

G

|

Global

| Mode and setpoint are not set by Unit Controller.

Menu advances to: FREE COOLING SUPPLY AIR SETPOINT

= 55°F

|

Not Applicable

|

Not Applicable

| Global input is energized by (P297-9). This setting is also used for outdoor air damper applications. Global input also brings on the blower. (This mode is NOT used when OAS signal is provided via network connec­ tion. GLO is only used when a 24VAC signal is used to energize the P297-9 GLO input.
Enthalpy includes effects of both temperature and humidity.

Economizer Start Up M3 Unit Controller

The unit will be equipped with either an M2 or M3 Unit Controller. M2 or M3 will be printed on the bottom of the Unit Controller near the SBUS connector. Use the appropriate start-up section in this manual and refer to the Unit Controller provided with the rooftop unit. Application manuals are available for both Unit Controllers. The economizer is controlled by the Unit Controller which is located on the unit control panel. A detailed menu layout can be found in the Unit Controller manual provided with each unit.

A Field Installed Economizer

The Unit Controller must be set to identify an economizer has been installed. The configuration ID will also identify which sensor inputs the Unit Controller will use to determine the free cooling mode. See figure 14 for sensor location.

• Use the Unit Controller keypad to enter the following menu: MAIN MENU> SETUP > INSTALL.
• Press SAVE until ONFIGURATION ID 1 appears.
• Change the second character in the configuration ID to identify the type of input used to determine economizer free cooling setpoint.
• Press SAVE. The Unit Controller is now set up to operate the economizer.
• Press the MAIN MENU button, then the BACK button, to display the status screen.

Adjust Free Cooling Discharge Air Setpoint

When outdoor air is suitable for free cooling, dampers will modulate to maintain a discharge air temperature of 55°F default (adjustable range 45-67 F).

Free Cooling Modes

The Unit Controller automatically sets the free cooling mode when the configuration ID is entered. The temperature setpoint mode is the only exception.

• Use the following menu path on the Unit Controller to enter the temperature setpoint mode.
• MAIN MENU > SETTINGS> RTU OPTIONS> DAMPER> ECONOMIZER TEMP ECON TYPE = TEMPERATURE OFFSET default.
• Use the Adjust and set values arrows on the keypad to select TEMPERATURE SETPT.
• Press SAVE.
• Note Network OAS signal and California Title 24 Compliance options use either TEMPERATURE OFFSET or TEMPERATURE SETPT mode.

Adjust Outdoor Air Free Cooling Setpoint

Note
Configuration ID 1 must be set to the appropriate mode before adjusting the free cooling setpoint.

Temperature Offset or Temperature Setpoint Mode

After the free cooling mode is saved, if default setpoint value needs to change, enter the new number and press SAVE. For California Title 24 compliance, adjust the free cooling setpoint based on the climate zone where the unit is installed. The setpoint requirement published by the California Energy Commission  Prescriptive Requirements for Space Conditioning Systems of the 2013 Building Energy Efficiency Standards.

Note
Values in the referenced standard will supersede values listed. When a network OAS signal is provided by a building control system, refer to control system literature to adjust free cooling setpoint.

Enthalpy Setpoint

The enthalpy sensor (A7) provides a milliamp signal to the Unit Controller based on outdoor air temperature and humidity.

Use the following menu to change the setpoint MAIN MENU > SETTINGS> RTU OPTIONS > DAMPER >ECONOMIZER ENTHALPY SETPOINT = 12.0 MA. At 12.0mA, the Unit Controller will allow dampers to modulate open at approximately 73°F. If the space temperature is too warm or humid, change the ECONOMIZER ENTHALPY SETPOINT to 13.6MA and the Unit Controller will allow dampers to modulate open at approximately 70°F.

Enthalpy Offset

The Unit Controller allows damper modulation when outdoor air is lower than return air by a differential or offset temperature and humidity range. Use the following menu to change the setpoint: MAIN MENU > SETTINGS> RTU OPTIONS > DAMPER ECONOMIZER ENTHALPY OFFSET = 1.0 MA Refer to table 6. At 1.0mA, the Unit Controller will allow dampers to modulate open when outdoor air is lower than return air by approximately a 2°F offset. If return air is 76°F, the Unit Controller will allow dampers to modulate open at approximately 74°F. If the space temperature is to warm or humid, change the ECONOMIZER ENTHALPY SETPOINT to 2.OmA or an offset of 3.5°F. The Unit Controller will allow dampers to modulate open at approximately 72.5°F.

E-Damper

Minimum Position Setting Use the menu path in table 8 to set the MIN DAMPER POSITION BLOWER ON HIGH when outdoor air is not suitable for free cooling. The minimum setpoint range is 0% open (dampers closed) to 100% (dampers fully open). On units with staged supply air blowers, also set the MIN DAMPER POSITION BLOWER ON LOW.

DAMPER OPTIONS

RTU OP­ TION

|

DAMPER

| ECONOMIZER ENTHALPY OFFSET = 12.0 MA
ECONOMIZER ENTHALPY SETPOINT = 1.0 MA
ECONOMIZER TEMP ECON TYPE = TEMPERATURE OFFSET OR TEMPERATURE SETPT
ECONOMIZER OAT SETPOINT = XX.X F
FREE COOLING SUPPLY AIR SETPOINT = 55°F
MIN DAMPER POSITION BLOWER ON HIGH = X.X %
MIN DAMPER POSITION BLOWER ON LOW = X.X %

Note
Menu options vary depending on hardware configuration .Use the Adjust and set values arrows to scroll up or down for selection options.

FREE COOLING OPTIONS

Config. ID1 POS 2| Unit Controller Input Mode| M4 Display

Free Cooling Options

| Default Setting| Range Setting|

Outdoor air is suitable for free cooling when:

---|---|---|---|---|---

T

| Differential Sensible Sensor default mode| ECONOMIZER TEMP ECON TYPE = TEMPERATURE OFFSET|

10°F

|

0°F – 40°F

|

Outdoor air temperature RT17 is less than return air temperature (RT16) by at least the offset value.

T

|

Single Sensible Sensor

| ECONOMIZER TEMP ECON TYPE = TEMPERATURE SETPOINT|

75°F

|

40 F – 75 F

|

Outdoor air temperature RT17 is less than the Out­ door Air Temperature set point value.

T

|

Network OAS

|

ECONOMIZER TEMP ECON TYPE = TEMPER­ ATURE OFFSET or SETPOINT

|

Not Applicable

|

Not Applicable

| Either of the TEMP modes (set point or offset) can be used when a network OAS signal is provided by an energy management or building control system, via BACnet, LonTalk, or L Connection. The network can command OAS, NOT OAS, or AUTO. AUTO returns to local control of OAS, which is the selected TEMP mode.

S

| Single Enthalpy* Sensor| ECONOMIZER ENTHALPY SETPOINT =

12.0 MA

|

12.0 mA

|

10mA – 19 mA

| Outdoor air enthalpy (A7) is less than enthalpy set point parameter.

D

| Differential En­ thalpy* Sensor| ECONOMIZER ENTHALPY OFFSET =

1.0 MA

|

1.0 mA

|

1 mA – 5 mA

| Outdoor air enthalpy* (A7) is less than return air enthal­ py (A62) by at least the OFFSET value.

G

|

Global

| Mode and setpoint are not set by Unit Controller.

Menu advances to FREE COOLING SUPPLY AIR SETPOINT

= 55°F

|

Not Applicable

|

Not Applicable

| Global input is energized by P297-9 This setting is also used for outdoor air damper applications. Global input also brings on the blower. (This mode is NOT used when OAS signal is provided via network connec­ tion. GLO is only used when a 24VAC signal is used to energize the P297-9 GLO input.
Enthalpy includes effects of both temperature and humidity.

Economizer Start Up M4 Unit Controller

The unit will be equipped with either an M2, M3, or M4 Unit Controller. M2, M3, or M4 will be printed on the bottom of the Unit Controller. M2 or M3 will be near the SBUS connector and M4 will be near the LED display. Use the appropriate start-up section in this manual and refer to the Unit Controller provided with the rooftop unit. Application manuals are available for all Unit Controllers. The economizer is controlled by the Unit Controller which is located on the unit control panel. A detailed menu layout can be found in the Unit Controller manual provided with each unit. A-Field-installed Economizer The Unit Controller must be set to identify an economizer has been installed. The configuration ID will also identify which sensor inputs the Unit Controller will use to determine the free cooling mode.

Field Installed Economizer

The Unit Controller must be set to identify an economizer has been installed. The configuration ID will also identify which sensor inputs the Unit Controller will use to determine the free cooling mode. Use the Unit Controller mobile application to enter the following menu: RTU MENU> SETUP INSTALL. Navigate through various setup questions until CONFIGURATION ID 1 appears. Change the second character in the configuration ID to identify the type of input used to determine economizer free cooling setpoint. Continue through the setup until complete.

Adjust Free Cooling Discharge

Air Setpoint When outdoor air is suitable for free cooling, dampers will modulate to maintain a discharge air temperature of 55°F default (adjustable range 45°-67°F).

Free Cooling Modes

The Unit Controller automatically sets the free cooling mode when the configuration ID is entered. The temperature setpoint mode is the only exception.

• Use the following menu path in the mobile application to enter the temperature setpoint mode.
• RTU MENU > SETTINGS RTU OPTIONS > DAMPER> ECONOMIZER TEMP ECON TYPE = TEMPERATURE OFFSET (default)
• Use the -/+ buttons to select TEMPERATURE OFFSET/SETPOINT
• Continue through the setup.
• Note Network OAS signal and California Title 24 Compliance options use either TEMPERATURE OFFSET or TEMPERATURE SETPT mode.

Adjust Outdoor Air Free Cooling

Setpoint Note Configuration ID 1 must be set to the appropriate mode before adjusting the free cooling setpoint.

Temperature Offset or Temperature Setpoint Mode

• After the free cooling mode is saved, press NEXT. If default setpoint value needs to change, enter the new number and press NEXT.
• For California Title 24 compliance, adjust the free cooling setpoint based on:
• The climate zone where the unit is installed. See table 4.
• The setpoint requirement published by the California Energy Commission.
• Prescriptive Requirements for Space Conditioning Systems of the 2013
• Building Energy Efficiency Standards.

Note
Values in the referenced standard will supersede values. When a network OAS signal is provided by a building control system, refer to control system literature to adjust free cooling setpoint.

Enthalpy Setpoint

The enthalpy sensor (A7) provides a milliamp signal to the Unit Controller based on outdoor air temperature and humidity. Use the following menu to change the setpoint:
RTU MENU > SETTINGS RTU OPTIONS > DAMPER > ECONOMIZER ENTHALPY SETPOINT = 12.0 MA.At 12.0mA, the Unit Controller will allow dampers to modulate open at approximately 73°F. If the space temperature is too warm or humid, change the ECONOMIZER ENTHALPY SETPOINT to “13.6MA” and the Unit Controller will allow dampers to modulate open at approximately 70°F.

Enthalpy Offset

The Unit Controller allows damper modulation when outdoor air is lower than return air by a differential or offset temperature and humidity range. Use the following menu to change the setpoint  RTU MENU > SETTINGS RTU OPTIONS > DAMPER > ECONOMIZER ENTHALPY OFFSET = 1.0 MA At 1.0mA, the Unit Controller will allow dampers to modulate open when outdoor air is lower than return air by approximately a 2°F offset. If return air is 76°F, the Unit Controller will allow dampers to modulate open at approximately 74°F. If the space temperature is to warm or humid, change the ECONOMIZER ENTHALPY SETPOINT to 2.0mA or an offset of 3.5°F. The Unit Controller will allow dampers to modulate open at approximately 72.5°F.

Damper Minimum Position Setting

Use the menu path in table 10 to set the MIN DAMPER POSITION BLOWER ON HIGH when outdoor air is not suitable for free cooling. The minimum setpoint range is 0%open (dampers closed) to 100% (dampers fully open). On units with staged supply air blowers, also set the MIN DAMPER POSITION BLOWER ON LOW.

DAMPER OPTIONS

RTU OPTION

|

DAMPER

| ECONOMIZER ENTHALPY OFFSET = 12.0 MA
ECONOMIZER ENTHALPY SETPOINT = 1.0 MA
ECONOMIZER TEMP ECON TYPE = TEMPERATURE OFFSET OR TEMPERATURE SETPT
ECONOMIZER OAT SETPOINT = XX.X F
FREE COOLING SUPPLY AIR SETPOINT = 55°F
MIN DAMPER POSITION BLOWER ON HIGH = X.X %
MIN DAMPER POSITION BLOWER ON LOW = X.X %

Note
Menu options vary depending on hardware configuration.  Use the Adjust and set values arrows to scroll up or down for selection options.

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