108833 Rev. C
7
S - 6 3 6 / S - 6 4 6
V. EMI (ELECTROMAGNETIC INTERFERENCE)
D.DISTANCE FROM THE SOURCE
WARNING
EM energy rapidly becomes more intense as you get closer to the
source. For this reason, EMI from hand-held devices is of special con-
cern. (
See C.1
) A person using one of these devices can bring high
levels of EM energy very close to your chair without you knowing it.
E. IMMUNITY LEVEL
WARNING
1. The level of EM energy is measured in volts per meter (V/m).
Every power wheelchair can resist EMI up to a certain level.
This is called its “immunity level”.
2. The higher the immunity level, the less the risk of EMI. It is
believed that a 20 V/m immunity level will protect the power
wheelchair user from the more common sources of radio waves.
3. The configuration tested and found to be immune to at least 20
V/m is: Quickie S-636 / S-646 power wheelchair with a right
hand mounted RNET remote joystick system, 20” seat width,
18” seat depth, dual-post height adjustable armrests, swing-
away hangers and GP 24 gel cell batteries.
4. Specialty input devices with an unknown immunity level
because the devices were not tested with the S-636 / S-646
and RNET controller include:
WARNING
Individuals with physical limitations requiring the use of
a specialty control input device known not to be
immune to 20 V/m, or not known, should exercise extra
care around known sources of EMI.
WARNING
There is no way to know the effect on EMI if you add
accessories or modify this chair. Any change to your
chair may increase the risk of EMI. Parts from other
suppliers have unknown EMI properties.
F. REPORT ALL SUSPECTED EMI INCIDENTS
WARNING
You should promptly report any unintended movement or brake
release. Be sure to indicate whether there was a radio wave source
near your chair at the time.
Contact: Sunrise Medical Customer Service Department at
(800) 333-4000.
• Breath Control
• Heavy Duty Switched
Joystick
• Proportional Head
Control
• Wafer Board
• Tri-Switch Head Array
• Proportional Mini-
Joystick/Chin Control
• Proximity Head Array
• Zero Touch Switch
• 4-Zero Touch Switch
• 5-Zero Touch Switch
• Treadle Switch
• Ribbon Switch
• Disc Switch
• Buddy Button
• Micro Light
• Star Board
• Penta Switch
• Plate Switch
• Soft Switch
• Grasp Switch
• Wobble Switch
WARNING
Heed all warnings to reduce the risk of unintended
brake release or chair movement:
1. Beware of the danger from hand-held transceivers.
Never turn on or use a hand-held transceiver while
power to your chair is on. Use extra care if you believe
that such a device may be in use near your chair.
2. Be aware of nearby radio or TV stations, and avoid
coming close to them.
3. If unintended movement occurs, turn your chair off as
soon as it is safe to do so.
A. WHAT IS EMI?
WARNING
1. EMI means: electromagnetic (EM) interference (I). EMI
comes from radio wave sources such as radio transmitters
and transceivers. (A “transceiver” is a device that both sends
and receives radio wave signals).
2. There are a number of sources of intense EMI in your daily
environment. Some of these are obvious and easy to avoid.
Others are not, and you may not be able to avoid them.
3. Powered wheelchairs may be susceptible to electromagnetic
interference (EMI) emitted from sources such as radio sta-
tions, TV stations, amateur radio (HAM) transmitters, two-
way radios, and cellular phones.
4. EMI can also be produced by conducted sources or electo-
static discharge (ESD).
B. WHAT EFFECT CAN EMI HAVE?
WARNING
1. EMI can cause your chair, without warning, to:
•
Release its brakes
•
Move by itself
•
Move in unintended directions
If any of these occurs, it could result in severe injury to you
or others.
2. EMI can damage the control system of your chair. This could
create a safety hazard, and lead to costly repairs.
C. SOURCES OF EMI
WARNING
The sources of EMI fall into three broad types:
1. Hand-Held Transceivers:
The antenna is usually mounted directly on the unit. These include:
Citizens band (CB) radios, “Walkie-talkies”, Security, fire and police
radios, Cellular phones, Lap-top computers with phone or fax,
Other personal communication devices
NOTE–
These devices can transmit signals while they are on, even if not in use.
2. Medium-Range Mobile Transceivers:
These include two-way radios used in police cars, fire trucks,
ambulances and taxi cabs. The antenna is usually mounted on the
outside of the vehicle.
3. Long-Range Transceivers:
These include commercial radio and TV broadcast antenna towers
and amateur (HAM) radios.
NOTE–
The following are not likely to cause EMI problems: Lap-top com-
puters (without phone or fax), Cordless phones, TV sets or AM/FM
radios, CD or tape players.
