B&K Precision 1655A - Manual - Manual (Page 2)

TEST INSTRUMENT SAFETY
WARNING
An electrical shock causing 10 milliamps of current to pass through the heart will stop most human heartbeats. Voltage as low as 35
volts dc or ac rms should be considered dangerous and hazardous since it can produce a lethal current under certain conditions. Higher
voltages are even more dangerous. Your normal work habits should include all accepted practices to prevent contact with exposed high
voltage, and that will 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:
1. The B+K Precision Models 1655A and 1653A AC Power Supplies are sources of high voltage ac. The person using the
instrument should be a qualified electronics technician or otherwise trained and qualified to work with high voltage.
2. Use only a polarized 3-wire ac outlet. This assures that the power supply chassis, case, and ground terminal are connected to a
good earth ground and reduces danger from electrical shock.
3. When servicing any equipment equipped with a two-wire ac plug, treat it as “hot chassis” type and connect it to the ISOLATED
OUTPUT outlet of the ac power supply. Even some equipment with a polarized plug is the “hot chassis” type.
4. Never connect two pieces of “hot chassis” equipment to ISOLATED OUTPUT outlets simultaneously. There may be a serious
shock hazard between two chassis.
5. Don’t expose high voltage needlessly. Remove housings and covers only when necessary. Turn off equipment while making
test connections in high-voltage circuits. Discharge high-voltage capacitors after removing power.
6. 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.
7. Use an insulated floor material or a large, insulated floor mat to stand on, and an insulated work surface on which to place
equipment; and make certain such surfaces are not damp or wet.
8. Use the time proven “one hand in the pocket” technique while handling an instrument probe. Be particularly careful to avoid
contacting a nearby metal object that could provide a good ground return path.
9. When testing ac powered equipment, remember that ac line voltage is usually present on some power input circuits such as the
on-off switch, fuses, power transformer, etc. any time the equipment is connected to an ac outlet, even if the equipment is
turned off.
10. Never work alone. Someone should be nearby to render aid if necessary. Training in CPR (cardio-pulmonary resuscitation)
first aid is highly recommended.