The factory has four main plants dedicated to high-quality integrated circuit manufacturing. The facility manager is looking for a solution to measure energy usage across different buildings, areas, and specific processes to lay the foundation for implementing energy-saving strategies. The maximum distance between the plants is less than 2 kilometers, and the project initially requires more than 100 decentralized monitoring points, with loads reaching up to 800A.

CET’s PMC-352 is a wireless IoT energy meter that uses the latest LoRa wireless technology. It operates in conjunction with the PMC-1303-3 LoRa Gateway, which works in the AS923 frequency band (with 16 frequency channels available for selection). The LoRa gateway efficiently transmits serial data packets between upstream network-based applications and downstream wireless LoRa meters via a TCP/IP connection. Each LoRa gateway can communicate with up to 128 wireless LoRa meters assigned to the same channel.

To solve potential interference issues, the LoRa meters and gateways are divided into four zones, with each zone assigned a different frequency channel. The PMC-1303-3 Modbus TCP-RTU Gateway is also deployed as an embedded Modbus master device, autonomously polling all PMC-352 LoRa meters via the LoRa gateway and subsequently providing the data through a Modbus TCP interface to the client’s SCADA or EMS system. This setup makes it extremely simple for the client’s system to collect data from these downstream LoRa meters over a local area network (LAN). Additionally, the system provides an intermediate buffer to store historical data from all connected devices and offers extra data redundancy.

For current measurement, the PMC-1303-3 uses either split-core CTs or Rogowski coils for easy, non-invasive installation. Rogowski coils offer several advantages over traditional iron-core CTs, such as being lightweight, having a large window size, greater mechanical flexibility, and the ability to measure up to 5000A with excellent linearity across a wide dynamic range. Specifically, Rogowski coils are used for circuits with multiple outgoing cables, where traditional iron-core CTs cannot effectively measure current.