18.
DISPLAY BACK-LIGHT SWITCH:
This switch controls the display back-
light. In low ambient light conditions, the back-light allows the operator to
see the display. If not needed, the back-light should be turned off to
preserve the battery.
4.2
SAFETY
CONSIDERATIONS
The measuring terminals of this instrument can be connected to lethal voltages
and hazardous current circuits. Professional organizations using this instrument
will normally have safety procedures covering such installations and users will be
trained to follow them. Not withstanding these conditions, certain precautions
should be followed when using this instrument.
1.
The chassis ground connection should
always
be firmly attached to the
system ground bus, even when an AC line cord is used.
2.
Connections should be established to the potential and current terminals
before the measuring circuit is energized.
3.
The use of potential leads containing high rupture fuses is recommended
in high KVA circuits.
4.
All current terminals should be tightly fastened, to avoid dangerous
terminal voltages and preclude ohmic heating at high currents.
4.3
USING THE INTERNAL BATTERY
NOTE: If the PMM-1 has been in transient for more than a week, it is very
important that the unit be given a full charge before being used in the
battery operation mode.
The internal charger will automatically charge the battery when the line power is
applied to the instrument. When the battery is charging, the `battery charged'
LED illuminates. The instrument can be used while the battery is being charged.
The BATTERY Charge LED also acts as low-battery indicator. This LED will
flash at a constant rate, once the battery charge drops below 25%.
11
Содержание PMM-1
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