A customer contacted us looking for a wireless intercom to connect between a downstairs and an upstairs room addition. They had a 3-channel intercom that communicated over the house wiring using FM frequencies. It used to worked fine except the few times when they plugged in a laptop nearby to charge. Then they got nothing but static. Then they purchased a high definition flat screen TV and the intercoms either had no communications at all or a lot of static. They purchased another set of intercoms with the same results.
These intercoms are also known as Power Line Carrier (PLC) intercoms. PLC intercom systems communicate using a very low FM frequency over your house’s existing 110 volt AC house wiring that supplies power to receptacles and light fixtures. You just plug them in anywhere you have an outlet and they’re ready to go. Technically they are not wireless, but they are sold that way.
While they sound like the ideal solution for basic applications, most users are typically not happy with these intercom systems.
These units are very susceptible to interference from both inside and outside the house or business. You may experience buzzing, poor audio, or they may work perfectly well for you. Or as the customer above experienced, they may work well for you and then when you or your neighbor adds some new electrical device, they could quit working for you. You also could experience problems with units not being able to communicate because of the way your house wiring is done. The signal may not be able to cross to the second “phase” of your house wiring (220 Volts is run to each house and then split into two phases to give you 110 Volts). These intercoms are usually very inexpensive. These systems are not recommended for most people, but they are cheap.
A couple of the brands you’ll find in these intercoms is Westinghouse and Novi.
Due to their high return rate, you won’t find PLC intercoms on IntercomsOnline.com .