Future EXPLORER MAGELLAN, User Manual, Page: 18 / 72

2 MOVEMENT AND CONTROLS
730 REV 09 DATE REV: 09/02/14 18 POWER CHAIR: EXPLORER MAGELLAN
2 Electrical and Magnetic Interference
Electro Magnetic Interference from Radio Wave Sources
Power wheelchairs may be susceptible to electromagnetic interference (EMI), which is interfering electromagnetic
(EM) energy emitted from sources such as radio stations, TV stations, amateur radio (HAM) transmitters, two-way
radios, and cellular telephones. The interference (from radio wave sources) can cause a powered wheelchair to
release its brakes, move by itself, or move in unintended directions. It can also permanently damage a powered
wheelchair’s control system. The intensity of the interfering EM energy can be measured in volts per meter (V/m).
Each powered wheelchair can resist EMI up to certain
intensity. This is called its ‘immunity level’. The higher the
immunity level, the greater the protection. At this time, current technology is capable of achieving at least a 20
V/m immunity level, which would provide useful protection from the more common sources of radiated EMI. This
powered wheelchair model as shipped, with a VR2 PG Drives Technology controller, has an immunity level of 20
V/m.
There are a number of sources of relatively intense electromagnetic fields in the everyday environment. Some of
these sources are obvious and easy to avoid. Others are not apparent and exposure is unavoidable. However, we
believe that by taking into account the warnings that follow, your risk to EMI exposure will be minimized.
The sources of radiated EMI can be broadly classified into three types: