BNC 577 - Manual (Page 7)

Model 577 Operating Manual 3
2 Safety Issues
The 577 has built in equipment protections to prevent harm to the unit and the user, if the equipment is used in a
manner not specified by the manufacturer the protection provided by the equipment may be impaired.
Normal use of test equipment presents a certain amount of danger due to electrical shock because it may be
necessary for testing to be performed where voltage is exposed.
An electrical shock causing 10 milliamps of current to pass through the heart will stop most human heartbeats.
Voltage as low as 35 VDC or 35 VRMS AC, should be considered dangerous and hazardous, as it can produce a
lethal current under certain conditions. Higher voltages pose an even greater threat because such voltage can
easily produce a lethal current. Your normal work habits should include all accepted practices that will prevent
contact with exposed high voltage and steer current away from your heart in case of accidental contact with a
high voltage. You will significantly reduce the risk factor if you know and observe the following safety precautions:
• If possible, familiarize yourself with the equipment being tested and the location of its high-voltage points.
However, remember that high voltage may appear at unexpected points in defective equipment.
• Do not expose high voltage needlessly. Remove housing and covers only when necessary. Turn off equipment
while making test connections in high- voltage circuits. Discharge high-voltage capacitors after shutting down
power.
• When testing AC powered equipment, remember that AC line voltage is usually present on power input circuits,
such as the on-off switch, fuses, power transformer, etc.
• Use an insulated floor material or a large, insulated floor mat to stand on, and an insulated work surface on
which to place equipment. Make certain such surfaces are not damp or wet.
• Use the time-proven “one hand in the pocket” technique while handling an instrument probe. Be particularly
careful to avoid contact with metal objects that could provide a good ground return path.
• Never work alone. Someone should always be nearby to render aid if necessary. Training in CPR first aid is
highly recommended.