Whose Problem is Dirty Power?
May 05, 2021
Dirty Power is a Synonym for Poor Power Quality
Power is generated by electrical generation companies and delivered to buildings and home basically via the three electrical grid delivery systems in the United States. The eastern grid system, the western grid system and the Texas Grid system. Some parts of Texas are tied into the eastern and western grid.
Every electrical company is regulated by its state public utility commission. Every electrical company has a guideline for electrical service to the user. Every guideline for electrical service has similar language as shown below for building and home owners in the service agreement when service is established to the business or home.Interruption & Liability
- The Company will endeavor, but does not guarantee, to furnish a continuous supply of electric energy and to maintain voltage and frequency within reasonable limits.
- The Company shall not be liable for any loss, cost, damage or expense that the customer may sustain by reason of damage to or destruction of any property, including the loss of use thereof, arising out of, or in any manner connected with, interruptions in service, variations in service characteristics, high or low voltage, phase failure, phase reversal, the use of electrical appliances, or the presence of the Company’s property on the customer’s premises, whether such damages are caused by or involve any fault or failure of the Company or otherwise except such damages that are caused by or due to the willful and wanton misconduct of the Company.
- The Company shall not be liable for damage to any customer or to third persons resulting from the use of the service on the customer’s premises or from the presence of the Company’s appliances or equipment on the customer’s premises.
- The Company shall not be responsible in any way for damage to the customer’s equipment that is due to failure of the customer to provide adequate protection.
- Protection against loss of voltage, voltage unbalance, undervoltage transient, sustained overvoltage, phase reversal, loss of synchronism, overcurrent, short circuit and single phasing is highly recommended for three-phase equipment and is the responsibility of the customer.
So now that the business and home owner has discovered that even if the electric utility is delivering dirty power from it’s still the business owner and the home owner’s responsible for any and all issues, problems and damages. What should a business owner or home owner do?
The best method locating the root cause of dirty power in business and homes is with a power study. A power study is recommended to run 7 days so that every minute of an entire week can be analyzed for power quality issues. It is best during the power study to inspect every electrical service panel for proper bonding, grounding and surge protection. Once, the power study is completed recommendations if required will be listed in the power study report such as issues shown below:
Seven major risk factors are listed below for the electrical company, business owner and home owners. A rule of thumb on who actually causes these issues is 20% electrical company and 80% business or home owners’ equipment and wiring.
Damage hazards from your point of use electrical device and the united states power grid
- Voltage Transient
- A transient voltage is a temporary unwanted voltage in an electrical circuit that range from a few volts to several thousand volts and last micro seconds up to a few milliseconds.
- Very short interruptions
- Interruption is defined as the decrease in the voltage supply level to less than 10% of nominal for up to one (1) minute duration. They are further subdivided into: Instantaneous (1/2 to 30 cycles), Momentary (30 cycles to 3 seconds) and Temporary (3 seconds to 1 minute).
- Long interruptions
- When the supply voltage has been zero for a period of time in excess of 1 min, the long-duration voltage variation is considered a sustained interruption. Voltage interruptions longer than 1 min are often permanent and require human intervention to repair the system for restoration.
- Voltage swell
- Voltage swell is basically the opposite of voltage sag or dip. Voltage Swell. The disturbance is also described by IEEE C62. 41-1991 as “A momentary increase in the power-frequency voltage delivered by the mains, outside of the normal tolerances, with a duration of more than one cycle and less than a few seconds”.
- Harmonic distortion
- Total harmonic distortion (THD) is a measurement that tells you how much of the distortion of a voltage or current is due to harmonics in the signal. Total harmonic distortion (THD) is a measurement that tells you how much of the distortion of a voltage or current is due to harmonics in the signal.
- Voltage fluctuation
- A voltage sag (U.S. English) or voltage dip (British English) is a short duration reduction in rms voltage which can be caused by a short circuit, overload, or starting of electric motors. A voltage sag happens when the rms voltage decreases between 10 and 90 percent of nominal voltage for one-half cycle to one minute.
- Voltage Unbalance
- Voltage unbalance occurs when the RMS line voltages on a poly-phase system are unequal. Voltages are seldom perfectly balanced between phases, but when this unbalance becomes excessive, it can create problems for poly-phase motors.
All of the above symptoms are dirty power terms for an assortment of power problems caused by an equally diverse range of power issues. To varying degrees, all of the issues have one thing in common: they can be disruptive, and sometimes expensive, to everyday operations. As well are difficult to located and repair.
How costly? In the Unites States, depending on what resource you rely on numbers range from 15 -250 billion dollars annually for just business owners. In business much of that comes from downtime, the cost of which can vary from a few thousand to more than $6 million per hour, depending on the type of facility in question. From a home owner’s point of view, it is the cost of different electrical devices and appliances failing. Many of these damages are not caused by lightning strikes and are not covered by insurance.
When the business owner and home owner elects to just repair or replace the damage equipment without finding the root cause of failure they are gambling that the same thing will not reoccur.
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