SECTION 3
OPERATION
A.
l�E N E R AL
a.
LINE VO:LiTAGE
l'nlcss otherwise specified RAC PAC is wired and calibrated for 220 V,
50 Hz when delivered from the factory . For other line voltages, connect the
transformer as indicated on it, and adjust the line voltage indicator accor
dingly.
For
llO
V or
ll
7 V lines replace the AC fus e for the higher value, indicated
over the fuseholder on the front panel.
Use slow blow fuses . For 60 Hz operation, see section 3R: "60 Hz operation" .
b.
LINE ON
The power supply is switched on with the toggle switch, marked " LINE ON" .
c. OUTPUT VO LTAGE
The desired voltage is set with the calibrated output voltage control, figure 1
pos.
10, 1 1 . The voltage control can be locked by turning the ring behind
the voltage control knob clockwise (figure 1 pos. 23). Read the output voltage
from the voltmeter on the front panel. Note that the voltmeter has two ranges
with automatic switch over. The range in use is shown on the voltmeter range
indicator (figure 1 pos . 5).
d. OV P
Set the "Overvoltage protection" control (figure 1 pos . 7) well above the desi
red output voltage, but below the voltage that could damage the load.
Usually the calibrated scale on the panel will give sufficient accuracy.
For higher accuracy, set the OVP to maximum and the voltage control to the
des ired trip over voltage for the OVP. Turn the OVP slowly
CCW
until the
output voltage suddenly disappears . Lock the OVP control.
WARNING: If RAC PAC is connected to an external power source, e, g. used
for charging a battery, the OVP MUST NOT BE USED.
Such an external power source can damage both the OVP thyristor and the
cable harness .
The OV P switched off by turning the control fully
CW
where it switches to an
OFF
position.
e. CURRENT LIMIT
Set ''Current limit" control at a value well above the expected peak current,
hut
below the value which could damage the load.
Read output current from the ammeter on the front panel. Also the ammeter
has
two ranges with automatic switch over (figure 1, pos . 6 ) .
8
