IL-Mini™ Chiller Performance and Energy Data Logging with Modbus Electrical Meters

//IL-Mini™ Chiller Performance and Energy Data Logging with Modbus Electrical Meters
IL-Mini™ Chiller Performance and Energy Data Logging with Modbus Electrical Meters 2017-07-14T12:56:20+00:00

Three-Phase Energy Data Acquisition System
using the IL-Mini™

The IL-Mini™ data logger coupled with one or more WNC Modbus output power meters results in a flexible, stand-alone, multi-parameter electrical power data acquisition system. Shown below is the IL-Mini™ logging electrical parameters from two 3-phase electrical loads. In the following Chiller Performance Analysis application, logging electrical parameters from the cooling tower fan(s), pump(s) and chiller compressor is readily handled with a single IL-Mini™ Data Logger and multiple Modbus networked electrical meters. This frees up the IL-Mini™ analog channels for additional sensor inputs such as temperature, flow, humidity, etc.

System Explanation

The WNC Modbus enabled electrical meter is configured as a Modbus Slave device, assigned a network address and connected to the high-voltage electrical service or load to be measured. The WNC requires electrical voltage sensing connections to each of the phases as well as current transformers (CT’s) for current measurement on each of the phase conductors. The WNC power meter runs autonomously sampling the phase voltages and currents very quickly, calculating phase voltages, phase currents, Power Factor, instantaneous power and a multitude of other electrical parameters. The WNC updates internal memory registers with these values as they are calculated.

The IL-Mini™ data logger enabled with the Modbus RTU Master option is connected to the WNC meter(s) via a twisted wire pair in a daisy chain configuration. During operation, the IL-Mini™ reads the WNC Slave device registers containing the electrical parameters and uses them in the Program Net per the user’s configuration, logging them to memory, performing calculations, alarming and more.

In addition to the Modbus interface, the IL-Mini™ also has 4 analog input channels and one digital input (Event, Counter or Frequency) to which other transducer and signal inputs can be connected for simultaneous data acquisition as in the following chiller monitoring example.

IL-Mini™ Programming

To configure the IL-Mini™ for the desired data acquisition and alarming functions, a program is built within the Logic Beach HyperWare-II software. This program is called a “Program Net” as it consists of a number of icons all visually connected together with a mouse to make a “network”. The Program Net is then uploaded to the IL-Mini™ memory where it executes. Due to the intuitive flexibility of the HyperWare-II software, there are unlimited data acquisition schemes that can be implemented with the Program Net.

Below is a Program Net that acquires electrical, temperature and humidity performance data on a vapor compression chiller system. Parameters measured and logged include:

Chiller Temperatures, Compressor Power, Run-Time Duty-Cycle and Ambient Condition Logging

System Components Used

The following components make up this chiller logging system. Links to the Logic Beach Website for further details are provided. Component costs are on the Logic Beach price schedules. Additionally, comments are included

Part Number Description Qty Comment
IL-Mini-LCD-MRM-TC IntelliLogger IL-Mini™ with the LCD display, thermocouple analog inputs and Modbus R4wTU Master options. 1 The display is not required but provides a great on-site display of actual readings during operation.
3539.22000 IL-Mini™ Surface or wall mounting bracket 1 If desired
WNC-3Y-480-PMB Electrical Meter; Modbus interface for 277/480Vac Wye electrical service with neutral 1 Other models are available for other service configurations.
CTS-750-100 Split-Core Curernt Transformer. 0.75” aperture (opening), 100Aac full scale. 2 CT’s with other apertures and full scale current ratings are available
RH-1A Humidity transducer 1 If not already owned.
Thermocouple Probes Thermocouple temperature probes 3 A variety of thermocouple probes are available from Logic Beach
HW2M HyperWare-II for IL-Mini™ Single User License 1 If not already owned.
USB Cable USB Cable; Type A to Mini-B 1 If not already owned. This is a common cable used with cameras and other USB devices.