Optional Component Operation - LG AR-DR12-05A Installation And Operation Manual

Exhaust Fan VFD Sequence
Optional Building Static Pressure Sensor
The exhaust fan is modulated based upon the signal from a building static pressure sensor. The microprocessor will modulate the exhaust
fan based upon a comparison of the building static pressure level reported from the sensor.
Optional Outdoor Air Damper Tracking
The microprocessor will proportionally modulate the exhaust fan based upon the outdoor air damper position.
Optional Supply Tracking
The microprocessor will proportionally modulate the exhaust fan based upon the supply fan.
Optional 0-10 VDC by Others to VFD
The supply fan is modulated by a 0-10 VDC provided by others in the field.
Outdoor Air and Recirculated (Recirc) Air Damper Sequence
Optional Room CO2 Sensor
The microprocessor will proportionally modulate the OA/RA dampers based upon a comparison of the CO2 set point to the actual CO2 level
reported from the sensor. As the CO2 level rises, the controller will proportionally modulate the outdoor air damper open, between the mini-
mum and maximum OA position.
Optional Building Pressure
The OA/RA dampers will modulate based upon the signal from a building static pressure sensor. The controller will modulate the dampers,
between the minimum and maximum OA positions, based upon a comparison of the building static pressure set point to the actual building
static pressure level reported from the sensor.
Exhaust Fan Only Power
The exhaust fan will have a dedicated power circuit where in the case of a power outage, the exhaust fan will still run. A phase monitor will
detect an outage or power loss and open the contact, disconnecting all power to the unit and controller. An external signal will need to be
sent to a relay to power the exhaust fan, enabling the fan to run at a maximum speed. This sequence is NOT to be used for high temperature
exhaust applications.
Electronically Commutated (EC) Condens-
er Fans with Standard Scroll or Digital Scroll
Compressors
The EC condenser fan will modulate up and down to maintain the highest liquid line
pressure. The factory set points are: Set (left dial): 23 barg; Diff (right dial): 5 barg.
Fan operation with these set points are as follows. The fan will be at max speed
(~1140 rpm) when the highest liquid line saturation temperature is 118°F (410 psig,
28 barg). The fan remains at max speed if the pressure is higher than 410 psig (28
barg). The fan will be at min speed (~180 rpm) when the highest liquid line saturation
temperature is 105°F (340 psig, 23 barg). Below this pressure, the fan will be off.
The fan modulates linearly between the min and max speeds. If unit is selected with
inverter compressor, reference the supplemental Reference Guide for Microprocessor
Controller.
Airflow Monitor
A factory-wired, mounted, and powered airflow monitoring system is provided in the
outdoor and/or exhaust air streams. The airflow control system offers the following
functionality:
• Display of outdoor and/or exhaust airflow rate in actual cubic feet per minute (CFM)
or actual liters per second (LPS) on a 16 character LCD display.

OPTIONAL COMPONENT OPERATION

Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. "LG" is a registered trademark of LG Corp.
Set (left dial): 23 barg
Diff: (right dial): 5 barg
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