Power Quality In The Workplace
Today, we live and work in a world where split-second power outages are no longer acceptable. Protecting the integrity of your computer or other sensitive electronic systems is vital to the success of your business.
While power disturbances have always been a part of an electric utility's distribution system, only recently have businesses become more susceptible to them. As the sophistication of data storage and process automation continues, it is important to understand how to protect your electrical system from these momentary disturbances. Today's computers and cash registers can lose valuable information when these disturbances occur.
What Could Be Affected
Personal computers have become the backbone of today's businesses. During momentary power outages, computers may suffer downtime or lose data. Short duration high voltage "transients" (sometimes called "spikes") can also cause damage to sensitive PC boards.
Most modern electronic office equipment is computer based. These devices may be susceptible to power disturbances causing equipment damage or malfunction. Examples of computer based equipment that may be susceptible to power disturbances include:
Electrical disturbances produced within your building can cause problems with sensitive equipment. Disturbances may occur more frequently and appear more severe depending on how close your sensitive equipment is to the disturbance source. Even a seemingly innocent coffee machine or photocopier switching on and off could cause problems with small computers or other electronic devices.
Any device that draws a fluctuating current or draws a great deal of power at start up can cause a problem.
Some of the more common sources of internal power disturbances are:
On the Utility System
Our electrical distribution system is subject to a number of external influences which can cause power line disturbances. Some of the more common are:
Several no-cost or low-cost steps may be taken to overcome or reduce power quality problems. A qualified consultant or electrician may be needed to perform some of these functions.
1. Inspect wiring to ensure that it's in good condition, properly sized and properly grounded. Many power quality problems originate from faulty or undersized neutrals. Check that proper wire sizes are being used to accommodate the circuit loads.
2. Check receptacles for ground continuity. Loose connections can create unpredictable problems.
3. Is the correct voltage being supplied at your premises? If in doubt, call our Technical Services Department at (905) 840-6300 for assistance.
4. Check that sensitive equipment is on a separate circuit from other appliances (coffee makers, copiers etc.) to avoid disturbances. Install a dedicated circuit from the electrical panel directly to the piece of sensitive equipment.
5. Regular backup of important electronic data is one of the best ways to protect programs and valuable information. Inexpensive software programs which regularly back up data are readily available.
6. If your computers or other sensitive electronic devices do not have surge protection, unplug them during thunderstorms.
7. Static electricity can cause loss of data or damage to the computer. Anti-static sprays and mats are available to reduce the impact. Static electricity can be minimized by maintaining at least 50% relative humidity or by installing computer-grade carpeting.
Medium Cost Solutions
1. Surge suppressors limit impulses or divert them to ground, so they are not passed through your sensitive equipment. Exact protection capabilities vary with the quality of the device. Since surge suppressors are relatively inexpensive it makes sense to install them as insurance to reduce the potential of equipment damage, particularly from lightning strikes.
2. Isolation transformers are specifically designed to prevent electrical noise on the power line from being passed through equipment. Isolation transformers do not regulate voltage, or protect against sags and surges. In some cases, large computer equipment includes protection as part of the computer's power supply. For more information, consult your computer supplier.
Higher Cost Solutions
1. Line/power conditioners provide several types of protection in one device. Conditioners often combine the properties of an isolation transformer, a surge suppressor and a voltage regulator (to maintain steady voltage). The term "power conditioner" is often used rather loosely and may not necessarily perform all three functions. You should be careful to get equipment which provides the degree of protection you need.
2. The Uninterruptible Power Supply (UPS) is a device which provides reliable protection from all power disturbances. These self-contained units provide short term battery power to allow you to properly shut down the sensitive equipment that is critical to your operation during a power outage. They are ideal for use with personal computers and small control systems since they can be placed close to the equipment they protect and require no special installation or ventilation. For the best protection against all power disturbances, the UPS must be the "on-line" type and not simply a "standby power supply."
Whether you are designing an electrical distribution system for a new facility or modifying your existing system, ensure it is designed to accommodate the type of equipment you need and install the level of protective equipment required.
Your equipment suppliers are familiar with Power Quality issues pertinent to their products and services; Also consult with them.
The information contained in this document is provided as a service. While every effort was made to provide accurate and complete information, we do not guarantee results nor do we assume liability for any loss, costs, damages or injury whatsoever, resulting from the use of this material.
All contents © 2012 Hydro One Brampton Networks Inc. All rights reserved.
175 Sandalwood Pkwy West, Brampton, Ontario L7A 1E8
This document was last modified on 07-19-2011.