An electrical appliance is designed to run at a specified voltage. The vast majority of the time, the voltage that the electrical utility delivers to our houses is constant, but it can vary under certain unusual conditions.
These can happen because of transmission equipment malfunction, lightning strikes, or accidental closing of transmission circuits due to weather, animal activity or other unusual events.
Protection Against Voltage Surges
Your appliances have many layers of protection against voltage surges. First, there are the fuses and/or circuit breakers in your house--they will "blow" and interrupt a circuit that becomes overloaded. Second, your larger appliances will often have an internal fuse. Third, solid-state electronics often have a surge protector (your laptop's power supply has one). Fourth, the electrical utility has its own protections against power surges.
Low voltage can occur during period of heavy electrical demand (such as during heat waves, when air conditioners are all running). The electric utility slightly decreases the amount of voltage being fed into the system to compensate for the high demand.
Effects of Low Voltage
Low voltage is not a problem for most appliances. Older appliances that use motors, such as refrigerators and dryers, may be in danger of having their motors overheat. Newer appliances that use electric motors have circuits that sense the motors' temperature and shut down the appliance when it overheats.
Ensuring Proper Voltage
If you have appliances that absolutely must receive the proper voltage at all times (such as sensitive electronics), then you should obtain a "dedicated" power supply, which will feed the same voltage to those appliances regardless of fluctuations in the voltage delivered to the house.
About Low-Voltage Thermostats
A thermostat is a common appliance in households that have gas, oil, electric, and even coal heaters. One great type of thermostat...
- The Effect of Harmonics on Electric Metering
Can a Sudden Power Outage Damage Electrical Appliances?
Electrical appliances will, of course, stop working if the power goes out. This is inconvenient but not necessarily harmful. When electrical power...
What Are the Causes of Blown Fuses on Heat Pumps?
Heat pumps are a clean, safe and efficient source of heat for residential applications. Unlike other heating systems, they don't generate heat...
Does an Extension Cord Reduce the Appliance Voltage?
Anything that resists the flow of electricity causes voltage to drop. How much the voltage drops and whether the voltage drop is...
What Are the Causes of Electrical Harmonics?
When the voltage or current wave in an electrical circuit becomes distorted, electrical harmonics occur. Harmonics can interfere directly with electric motors...
Home Appliance Dangers
Appliances serve many purposes within the modern home, and help homeowners complete a wide range of tiresome tasks. Some appliances, however, can...