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H3BH
H3BH
299
Precautions
Caution
Do not change the time unit, or operation mode while the Timer
is in operation. Otherwise, the Timer may malfunction or suffer
from damage. Be sure to turn off the power supply of the Timer
before changing the time unit, rated time or operation mode.
How to Change Rated Time
Dial digits (0 to 0.5, 0 to 1.0, 0 to 5, or 0 to 10) appear in the six win-
dows around the time setting knob according to the rated time se-
lected by turning the rated time selector (i.e., rotary switch) located
at the lower-left corner of the front panel.
Switch Setting
The selector switches for time unit, scale, and function can be
turned in both directions, clockwise and counterclockwise. Each se-
lector switch has a snap mechanism that secures the switch at a giv-
en position. Set the switch at a position at which it is secured. Do not
set it midway between two securing positions because such prac-
tice may causes the Timer to malfunction or, in the worst case, break
down.
Accurately move and set the scale selector switch, matching the 0
position mark to a division on the scale.
Wiring
Since the H3BH uses a high-impedance circuit, the induced voltage
may disable it from releasing. To prevent this, keep the wiring as
short as possible. Also, do not run the wiring in parallel to power
lines. In case the induced voltage is more than 30% of the rated volt-
age, connect an RC filter (C = 0.1
&
F, R = 120
$
) or bleeder resistor
across the power terminals. Connect the bleeder resistor also when
the residual voltage is caused by a leakage current.
WARNING
Electrical Shock Hazard
Never touch the input terminals of any H3BH Timer while pow-
er is being applied to the Timer.
!
!