5 . Connect an external resistor, g1vmg 100 % output current to
' '+"
and
1 1 - 1 1
terminals ( 1 8 , 20) . Increas e the voltage, watching both the voltmeter and the
ammeter (4) . Also check that the ammeter changes range (6) near FS of
lower rangeo
6 . Disconnect the load at full output voltage and check that the voltmeter
does not change .
7 .
Turn the " Current limit" slowly CCW, watching that the ammeter tracks
the scale of the " Current limit" control approximately and that the "CV-CC
indicator" (2) switches to C C .
8 . Set the voltage control to 2 5 V on 3 2 V models and to 55 V on 60 V
models . Set the OV P control to 30 respectively 60 V.
Increas e the "Voltage control" and check that the output voltage disappears
when the OVP value is reached.
C . COVER REMOVAL
Switch off the line voltage .
Upper cover: Remove the blue strip marked " Pull to open' ' .
Cover plates are removed.
Bottom cover: Identically removed as upper cover.
Now the main PC board is accessible by folding it out from the chassis by
twisting three fasteners 1/ 4 turn.
Exchanging OV P fuse: With RA C PAC 150 and 300 this fuse is located at the
right side. With RACPAC 600 and 1000 it is found at the rear side.
D. ALIGNMENT PROCEDURE
In the following paragraphs a to e the main part of the alignment procedure is
described. This alignment is completed when the power supply is delivered
from the factory
o
Though it is unlikely that the power supply will fall out of
trim when used under normal operating conditions, it is advisable to check
,
alignment once a year, to be sure it fullfills the specifications .
After replacing components it is necess ary to check the circuits concerned,
especially after transistor replacement.
Further information on necessary tests is given in section 6 , table 8 .
3 9
