B.
E N V I R O N M E N T A L C O N D I T I O N S
RAC PAC is designed for operation under conditions where the vertical
ventilation through the perforated cover plates is free.
Of cours e, it is also essentia that the rear extrusion with the power
transistors has free access to cooling air.
Sufficient vertical ventilation is achieved when RAC PAC stands on a bench
and is provided with plastic feet.
When rack-mounted, a corresponding distance (20 mm) to the nearest
obstrucle top and bottom is sufficient, provided it is not a heat generator.
If so, the temperature of the air below RAC PAC , under worst heat generating
conditions, has to be regarded as the cooling air for RACPAC . For maximum
operating ambient temperatures see section 2: "Specificationsi' .
IF THE ENVIRONME NTAL CONDITIONS MENTIONED
DO
NOT A PPLY,
RACPAC HAS TO BE EQUIPPED WITH AN EXTERNAL FAN.
See s ection 3 P : "Accessories " .
C. NORMAL OPERATION
D
0
0
Figure 2
0
INT
0
DO
I
G
The "Normal- Parallel" switch S4 on the main PC-board is in "Normal"
position (as delivered from the factory) .
The "sense'' switch S2 is in position " INT" . The output may be positive,
negative or floating, depending on how jumper A in figure 2 is connected.
It is
that the load is connected to the terminals marked
"+"
and
"-"
the " s ense" terminals for current
RAC PAC .
This applies for all RAC PAC
D . REMOTE SENSING
D
0
0
EXT
Figure 3
0
0
9
