DC/DC Converter
PSC30
User Manual
Page 5 (24)
©2009. ELTEK VALERE DEUTSCHLAND GmbH.
UM_PSC30_E_EVD_2011-01-19.doc
3.
Start up procedure
Before connecting to the input voltage, it should be checked whether the voltage information on
the rating plate corresponds to the available voltage and also that the polarity corresponds to the
connection plan of the plug. The mains connection is done via a unit plug at the front side. The pro-
tective conductor should be generally connected (protection class 1, leakage current
3.5 mA).
Important:
If one pole of the output side has been earthed, then the SMPS unit should be grounded via the
separate PE connection on the front plate at the left side close to the DC- output connection.
In this case, the protective conductor at the input side should not be connected via the input plug
(earth circuit). This is particularly important for parallel connection without external decoupling di-
odes.
The DC-output connection is done via a SUB-MIN-D-plug of design 21 WA4 on the front side. The
output plug also includes the connections for the signals, sensor cable connections, symmetry regu-
lation and temperature sensor lead.
Note:
The SMPS is equipped with a high capacitive capacitor connected at the output. If the SMPS output
in the dead state is connected “hard” to a battery or other parallel operating SMPS, then it results in
a considerable surge of charging current, which could lead in welding the plug contacts when the
plug is inserted.
This can be avoided by the following procedures:
Switch on the SMPS before mounting without the output plug; insert the connection plug only
after the adjusted output voltage is attained.
Disconnecting the DC- circuit by switch or fuse
Charging using a protective resistance (approx. 1 Ohm/V)
Use of decoupling diodes
After switching off the unit, the capacitors in the input and output circuits can still conduct voltage;
the discharge time of the input circuit is approx. 4 seconds, that of the output circuit is approx. 15
seconds.
The SMPS unit operates with forced air cooling. The temperature of the inflow air should not exceed
45
o
C. Cabinet rooms should be designed for max. ambient temperature of 40
o
C. Temperatures of a
maximum of 60
o
C are permitted for short time or in the case of forced cooling of the cabinet, but
should be avoided on the behalf of the lifetime of the unit.
The power loss per unit is approx. 220 W (depending on the type).
4. Operation
The unit is operated via the operating elements arranged on the front plate. These are described in
the respective sections and are assigned by the labels on the front plate of the unit (see section
7.1/7.2).
