Power Monitoring with MW100 and PR300

Introduction

A large OEM parts supplier to the automotive industry has been a Yokogawa customer for several years. In the past, Yokogawa sold the customer field instruments and data logging equipment for measuring and recording environmental conditions within their facility. A new application surfaced; the customer wants to measure and quantify the electrical energy consumption and other utility costs for each assembly line so they can accurately assign these costs to each component. Yokogawa was called in to assist with the project.

Application

The customer has over one hundred assembly lines or work cells targeted for energy monitoring. The plant provides pressurized air and nitrogen as well as electricity to operate each work cell. In order to determine the true cost to manufacture each component the amount of air, nitrogen and electricity needs to be displayed, totalized and logged. Historical consumption data saved by the PC data logging software will run through calculations using energy cost rate information to determine the energy cost for the assembly line over a specific time period. The customer also wants a low cost method for line managers to have real-time access to the process data. The new system must be network-enabled and easy for the instrument and control technicians to configure and maintain.

Solution

An integrated system was proposed using an MW100 for data logging, two PR300 power meters for the electrical measurements and a Yokogawa flow meter and differential pressure transmitter for the air and nitrogen measurements. A custom enclosure with a 24 VDC power supply for the field instruments, circuit breakers and terminal blocks would house the MW100 and power meters.

A local Yokogawa systems integrator designed and built the enclosure containing the instrument package. The project sales engineer configured the MW100 for MODBUS data communications with the PR300s and the flow rate measurements. Nitrogen and airflow are measured in Standard Cubic Feet per Minute then totalized and grouped in math channels. The math groups are reset at midnight daily so a consumption total is provided each day.

The PR300s measure a mix of single and three phase electrical loads on five separate panels. Each PR300 provides panel voltage, current and kWh consumption values to the MW100 using serial MODBUS RTU communications. This data is read by the MW100 and placed in math channels. All data is archived by the MW100 to the CompactFlash™ card. DAQLOGGER software with Gate MX/MW (required when used with MW100) gathers all MW100 real-time channel data (including PR300 data on math channels) via an Ethernet network connection.

Any PC in the plant will allow the managers to view MW100's real-time data and alarm events via Internet Explorer – a great convenience and cost-saving feature since no additional software is needed.