Paper Presentations

What You Should Know About Your Digital Power Meter
Jon Bickel, Schneider Electric/Square D Company

Digital power meters are very powerful tools that help manage energy usage and ascertain the level of power quality on an electrical system. However, there are certain pitfalls that may be encountered when converting an analog signal into a digital signal. Two primary concerns are loss of data and conversion errors. Undersampling an analog signal will result in the loss of valuable data making the analysis of an event more difficult. Conversion errors during the process of transforming the analog signal to a digital signal introduce inaccuracies into the data that can mislead the end-user. Understanding the factors that facilitate these concerns will help the end-user understand the limitations of their digital power meter and aid in selecting the appropriate digital power meter for a specific application.

Case Study: Embedded Internet Based Power Monitor Field Data
Kevin Harris, TEAL Electronics

In late 2004, TEAL Electronics introduced the TEALwatch™ Power Monitor, a low-cost web-based embedded power monitor for installation into permanently installed Original Equipment Manufacturer’s (OEM) 3-phase power subsystems. Production units began shipping in the first quarter of 2005, and TEAL anticipates hundreds of systems to be installed throughout 2005.

The web-based TEALwatch™ power monitor enables the user to remotely monitor their sites 24x7x365 from anywhere in the world, at anytime. Using a common web browser interface with no special software required appeals to the OEM customer that will install tens or hundreds of their systems each year, each with an integrated power subsystem and power monitor. As compared to the more traditional temporary power monitoring for OEMs, having a monitor permanently installed at each site can help prevent costly and repetitive site problems by identifying if the AC power is related to a specific site problem at anytime. To make an embedded power monitor solution feasible, the device must be low cost, and to capture typical power quality events, it must be relatively high performance. The TEALwatch™ combines ease-of-use with a powerful and fully customizable user interface, appealing to many different users. TEAL will present data from our installations in the field, including customer feedback and comments, regarding the usefulness of a permanently installed power monitor in OEM equipment.

Predictive and Preventive Maintenance (PdM) Using Power Quality and Thermographic Portable Tools
John Carroll, Fluke Power Quality

When conducting predictive maintenance, mechanical measurements such as vibration and ultrasound are employed to determine impending failure conditions on rotating machinery. In much the same approach, Electrical Predictive and Preventive Maintenance (PdM) methods are used to determine the likelihood of impending failures due to electrical power problems.

In this paper, we focus on two specific electrical preventive maintenance tools – power quality measurement and thermographic imaging. We will explain and illustrate the methods used to identify power quality problems, determine why they are present and offer mitigation solutions using portable hand held tools. We demonstrate the use of both electrical 3 phase portable Power Quality equipment and Thermography Image tools, which compliment each other and give the user strong visual evidence of impending power problems.

One of the most common Power Quality problems is excessive heat due to high harmonic conditions on electrical branch circuits and neutral conductors. This paper will illustrate the use of both harmonic profiles and thermal images to provide a predictive and preventative maintenance philosophy which results in lower maintenance costs through reduced downtime, equipment repair and spare parts inventories. Fluke Power Quality and Fluke Thermography have combined its resources to present a strong message about preventative troubleshooting techniques.