Ahu Kit Introduction - LG PAHCMS000 Installation Manual

Introduction
The PAHCMS000 AHU Communications Kit bridges LG's air conditioning outdoor unit to a third party Air
Handling Unit (AHU). Its function is based on discharge or supply air temperature control. In installations
where the AHU is designed with Direct Expansion (DX) Coil, the PAHCMS000 will control the supply air
temperature by measuring the inlet and outlet temperatures of the DX coil and changd the operation of
the outdoor unit and the expansion unit. PAHCMS000 AHU Communications Kit features are:
• It can be used with LG Multi V air or water source outdoor units and LG Single Zone outdoor units.
• It supports AHU coil capacities from 12 - 594 kBtu/h.
• It controls the Electronic Expansion Valve (EEV, required, sold separately)
• It measures the supply air temperature through the enclosed temperature sensor and controls the
outdoor unit to secure the demanded supply air temperature.
• It can be directly connected to direct digital control (DDC) without a separate control module, so DDC
can receive product control and status information through Modbus communication.
• The PAHCMS000 AHU Communications Kit consists of a chassis, communication module, pipe-in
thermistor, pipe-out thermistor, and return air thermistor.
• Supply air temperature control is possible without DDC.
• It increases heating comfort by applying sequential defrost logic and simultaneous defrosting preven-
tion logic of the outdoor unit.
Figure 2: AHU Communications Kit System Schematic.
Thermistor
Third-Party
Air Handling
Third-Party
AHU
Controller
1
Pipe In
Sensor
(Liquid)
Return Air
3
Air flow
Pipe Out
Sensor (Vapor)
Unit
Control Signal (field supplied)
Thermistor Signal
Third-party AHU controller is recommended.
1
LG wired controller (required accessory) functions as error code display only.
2
No system control available.
Return air temperature thermistor can be replaced with fixed resistor when AHU
3
controller is using third-party temperature sensors.
Compatible units are Multi V and Single Zone.
4
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.

AHU KIT INTRODUCTION

LG AHU
Comm Kit
PAHCMS000
Max
Length
32 feet
LG AHU
EEV Kit
Liquid
Piping
Vapor
Piping
Pipe
Refrigerant flow (cooling)
Refrigerant flow (heating)
Figure 1: PAHCMS000 AHU
Communications Kit.
LG Wired
Controller
2
LG Multi V
Air Source or
Water Source Unit
4
7