Weather and Outages
NB Power employees do regular maintenance programs, such as line checks and tree trimming, to ensure maximum reliability of our power lines and infrastructure. This maintenance is key to helping to avoid unplanned power outages for our customers, even in the event of major weather events.
However, no matter how well we plan, prepare and maintain our facilities, mother nature can easily let us know who really is in charge by sending us severe weather, sometimes making our job of Power Restoration challenging.
Severe weather conditions in New Brunswick that adversely affect power distribution can be generally categorized into any combination of rain, freezing rain, snow and high winds. The calendar below shows when these conditions are typically experienced here in New Brunswick. Click on the conditions listed in the calendar for more information.
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Rain can cause havoc on insulation of high voltage lines by reducing the insulation properties of porcelain bushings, switches, and the pin insulators that attach the lines to the poles.
Insulators play an important role in keeping the flow of electricity moving and not shorting out on structures. Any crack or breakage of an insulator allows water, mostly in the form of rain to cause a failure. This failure interrupts power by blowing a fuse, not unlike the ones found in our fuse panel in our homes.
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Freezing rain poses a special concern with the electrical system where it tends to stick and build on all components. This may cause the same issues as rain in that it may compromise insulation.
Freezing rain can also build on conductors and sometimes causes them to form a heavy ice shell many times the diameter of the conductor and in some cases, when the weight exceeds the design strength of the wire, it breaks and falls to the ground resulting in an interruption.
Freezing rain also interacts with tree limbs that may be in close proximity, weighing down and contacting the conductor which in turn causes a short circuit, eventually resulting in an interruption.
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Dry snow normally does not cause much concern with the electrical system. Wet snow, however, poses some of the same concerns that freezing rain does in that there is potential for insulation breakdown due to moisture or snow loading on tree limbs causing conductor contact and eventual power interruptions.
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These higher strength winds have the potential of breaking trees and tree limbs causing them to fall over the lines. They can also cause a conductor fault. In this instance, the customer may see the lights go out and return within seconds as our breaker protection momentarily clears the fault and recloses. If the fault is gone the power remains on. This type of momentary interruption may also occur when a tree limb falls onto the line and then falls off.
High winds also have the potential of creating salt spray conditions in our coastal areas that can cause some of our equipment to fail.
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These lower strength winds typically create outages when the leaves are still present on trees. They act as a sail that in turn can increase the stresses on tree limbs and in turn contribute to the damage to the tree and our equipment. They have the potential of breaking trees and tree limbs causing them to fall over the lines.
Moderate winds also have the ability to cause conductor fault. In this instance, the customer may see the lights go out and return within seconds as our breaker protection momentarily clears the fault and recloses. If the fault is gone the power remains on. This type of momentary interruption may also occur when a tree limb falls onto the line and then falls off.
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When drastic temperature variation is present, lightning may result. Power interruptions can result when lightning contacts our structure or power lines. Lightning arrestors are placed at strategic places on the lines to protect critical switching and voltage regulation components.
Often with lightning storms there are periods of severe winds for brief periods that can also cause problems for our lines.
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During the winter months severe cold is a fact of life in New Brunswick. Common failures associated with severe cold are frost breaks on conductors, system overload, and insulator failures.
During these cold snaps when the power goes out, our first reaction may be to turn heaters and lights on in anticipation of our power being restored. This can sometimes extend the outage because the fusing may be unable to take the stress of the high demand for power during the cold load pickup. Customers should wait for the power to return and slowly add their power requirements a bit at a time.