LG AC Smart II PQCSW320A1E VRF Central Controller

LG AC Smart II PQCSW320A1E Advanced Central Controller

The LG AC Smart II PQCSW320A1E is a central HVAC controller engineered for LG Variable Refrigerant Flow (VRF), Multi V, and Duct-Free Split (DFS) networks. Operating on an embedded Windows CE Core 5.0 architecture with a 7-inch resistive color touchscreen, it executes deterministic RS-485 communication over LG’s proprietary LGAP (LG Air Conditioner Protocol) bus.

Out of the box, the unit polls and commands up to 64 indoor devices across 16 outdoor systems. Installing the optional PQCSE440U0 expansion module doubles addressable capacity to 128 indoor devices. Integrated Ethernet ports allow remote browser-based supervisory control, while dedicated binary contact inputs handle fire-alarm emergency shutdown interlocking.

Model Details

• Model Name: AC Smart II (Advanced Control Smart II)
• Primary Manufacturer Part Number (MPN): PQCSW320A1E
• Regional / Suffix Variants: PQCSW320A1E.ENCXLEU, PQCSW320A1E.ANCXLAP
• Internal Main PCB / Assembly P/N: EBW36108027
• Manual Part Number: MFL62077702

Features

1. Hardwired Emergency Stop Interlock: Dedicated binary input terminal accepts fire-alarm or safety-relay contacts to execute an immediate system-wide compressor and fan shutdown.
2. Dual Ethernet & Embedded Web Server: Enables simultaneous local LAN monitoring and remote browser-based diagnostics without requiring dedicated middleware PCs.
3. Granular Local Controller Lockouts: Restricts unauthorized crew or occupant tampering by locking power, operating mode, fan speed, or upper/lower temperature setpoints on wall thermostats.
4. USB Firmware & Configuration Portability: Supports rapid OS/firmware updates and full site database cloning via standard USB flash memory.

Applications

• Marine & Offshore Accommodation HVAC: Centralized climate control for vessel crew quarters, mess rooms, wheelhouses, and offshore living quarters fitted with LG Multi V marine/commercial VRF systems.
• Commercial Office Towers & Hotels: Multi-floor zone scheduling, occupied/unoccupied setback automation, and tenant energy allocation via PDI integration.
• Healthcare & Laboratory Facilities: Strict temperature band enforcement and central fault code logging across isolated climate zones.
• Educational & Government Campuses: Automated holiday/weekly scheduling and remote Ethernet troubleshooting across distributed building wings.

Terminal & Port Allocations

• Rear DC Power Input: Accepts regulated 12V DC (1.5A) from the supplied switching adapter. Verify polarity prior to energizing.
• RS-485 Communication Terminals (BUS_A / + and BUS_B / -): Polarity-sensitive differential pair connecting to outdoor unit central control terminals (CN_CENTRAL / A & B) or PI485 gateways. Terminate shield drain wire at one end only to prevent ground loops.
• Emergency Stop Contact Terminals: Two-wire binary input supporting either dry contact (non-voltage) or active voltage interlock signals from a shipboard fire alarm panel or building safety relay. When triggered, the controller broadcasts a global stop command across all 64/128 connected units.
• Ethernet Ports (Internet A / Internet B): Standard 10/100Base-T RJ45 jacks for LAN/WAN connection, PC browser access, or upstream BMS gateway routing (PBACNA000 / PQNFB17B0 / PQNFB16A1).
• Bottom SD Card & USB Interfaces: Recessed SD slot accepts licensed option cards; USB port accommodates FAT32 flash drives for firmware flashing and configuration backup.

Compatibility

• VRF Systems: LG Multi V II, Multi V III, Multi V IV, Multi V S, and Multi V Water IV (Heat Pump and Heat Recovery series).
• Duct-Free Split (DFS) & Multi-Split: Compatible with Single Zone, Multi F, and Multi FDX indoor units when paired with an outdoor PI485 interface board (PMNFP14A0 / PMNFP14A1).
• Ventilation & Air Handling: LG Energy Recovery Ventilators (ERV / ERV DX) and Air Handling Unit (AHU) communication kits.
• Power Distribution Monitoring: Interfaces with LG Power Distribution Indicators (PQNUD1S00 / PQNUD1S40 / PPWRDB000) to display real-time kWh consumption per indoor zone.
• BMS Gateways: Integrates upstream into BACnet IP / Modbus TCP (PBACNA000), BACnet MS/TP (PQNFB17B0 / PQNFB17C0), and LonWorks (PQNFB16A1) networks.

Part Number Cross-References

• Predecessor Model: PQCSW320A0E (AC Smart / AC Smart I)
• Direct OEM Successor / Upgrade: PACS5A000 (AC Smart 5 — backward-compatible replacement for PQCSW320A1E and PACS4B000)
• Premium Series Equivalent: PQCSW421E0A (AC Smart Premium)
• 128-Unit Expansion Kit: PQCSE440U0
• SD Card Option Kits: PQCSE341A0 / PQCSE342A0

Frequently Asked Questions

What is the difference between LG PQCSW320A0E and PQCSW320A1E?

The PQCSW320A1E is the updated hardware and firmware revision of the original PQCSW320A0E AC Smart controller. Both share the same 217 × 124 × 40 mm wall-mount footprint, 7-inch touchscreen, 12V DC input, and 64-unit base capacity (expandable to 128 units via the PQCSE440U0 kit), while the A1E incorporates updated Windows CE firmware builds and expanded accessory support.

Does the LG PQCSW320A1E have onboard Digital Input (DI) and Digital Output (DO) relays?

The PQCSW320A1E includes a dedicated binary input terminal strictly for Emergency Stop interlocking (compatible with dry-contact or voltage-based fire alarm signals). It does not feature general-purpose onboard Digital Output (DO) relays; if your project requires dry-contact status outputs, you must add an external LG DO Kit (PQNFP00T0) or upgrade to an ACP controller.

Can the LG AC Smart II connect directly to BACnet or Modbus BMS networks?

No, the PQCSW320A1E communicates natively over LG’s RS-485 LGAP bus and HTTP/Ethernet for web browser access. To integrate the system into a BACnet IP, BACnet MS/TP, Modbus TCP, or LonWorks Building Management System, you must connect an LG protocol gateway such as the PBACNA000, PQNFB17B0, or PQNFB16A1 onto the central control network.

What replacement model should I use if the PQCSW320A1E is discontinued or out of stock?

LG designates the AC Smart 5 (MPN: PACS5A000) as the direct OEM replacement for legacy PQCSW320A1E and PACS4B000 controllers. The PACS5A000 natively supports up to 128 indoor units without requiring a separate expansion card and connects to the same RS-485 LGAP V-Net communication bus.

What wire gauge and cable type are required for the PQCSW320A1E RS-485 bus?

You must use 2-conductor, stranded, twisted-pair shielded copper cable with a minimum cross-sectional area of 0.75 mm² (18 AWG). Connect BUS_A (+) and BUS_B (-) consistently across all outdoor units and gateways in a daisy-chain topology, grounding the cable shield at a single point only.