Inverters: Part 1, Electronic Loads, Surge Protectors and Radio Interference

©2003 Windy Dankoff

Sizing an inverter for electronic loads

Most electronic devices (especially stereo and music amplifiers, computers and TVs) are labeled with power ratings that are based on absolute maximum or surge conditions, for the purpose of sizing power circuits. Their actual power draw may be HALF of that, or less. The best way to measure the peak and average power consumption is to use a Brand Power Meter.

Surge protector warning

Do not use household or computer type surge protectors on circuits powered by a "modified sine wave" inverter. They may overheat. Inverters do not produce dangerous spikes or surges, so protectors are not necessary. EXCEPTIONS: Use a lightning arrestor on any long AC feed line to another building, for example, or to a well pump. Long lines can pick up induced surges from lightning, and feed them back to the inverter and to the AC circuits. The Delta LA-AC Lightning Arrestor is appropriate. Place it at the beginning of the line, close to a main ground connection.

AM radio interference

ALL inverters produce radio interference in the AM and shortwave bands. It may be necessary to use a radio that is powered by DC or internal batteries, and is not located near the inverter. To hear distant stations, it may be necessary for the inverter to be off.