02002183 Revision A, January 2006
Metro Power
III
Owner’s Manual
8
POweRed wHeelCHAIR eleCtROMAgnetIC InteRfeRenCe (eMI)
Because EM energy rapidly becomes more intense as one moves closer to the transmitting antenna
(source), the EM fields from hand-held radio wave sources (transceivers) are of special concern. It
is possible to unintentionally bring high levels of EM energy very close to the powered wheelchair’s
control system while using these devices. This can affect powered wheelchair movement and brak-
ing. Therefore, the warnings that follow are recommended to prevent possible interference with the
control system of the powered wheelchair.
eMI wARnIngs
Electromagnetic interference (EMI) from sources such as radio and TV stations, amateur radio
(HAM) transmitters, two-way radios, and cellular telephones can affect powered wheelchairs. Fol-
lowing the warnings listed below should reduce the chance of unintended brake release or powered
wheelchair movement which could result in serious injury.
Warning: Do not operate hand-held transceivers (transmitters-receivers), such as
citizens band (CB) radios, or turn on personal communication devices, such as cel-
lular telephones, while the powered wheelchair is turned on.
Warning: Be aware of nearby transmitters, such as radio or TV stations, and try to
avoid coming close to them.
Warning: If unintended movement or brake release occurs, turn the powered wheel-
chair off as soon as it is safe.
Warning: Be aware that adding accessories or components, or modifying the pow-
ered wheelchair, may make it more susceptible to EMI (note: There is no easy way
to evaluate their effect on the overall immunity of the powered wheelcchair).
Warning: Report all incidence of unintended movement or brake release to Everest
& Jennings, and note whether there is a source of EMI nearby.
IMPORtAnt InfORMAtIOn
1) 20 volts per meter (V/m) is a generally achievable and useful immunity level against EMI (as of
May 1994) (the higher the level, the greater the protection);
2) The immunity level of this powered wheelchair model is listed on page 7.
Be aware that using different components, adding accessories, or modifying the powered wheelchair
may change the immunity level.
