Replacing The Fuse; Functional Description - Conrad PS 303 Pro Bedienungsanleitung

Replacing the fuse

If it is no longer possible to switch on the power supply, the mains fuse has probab-
ly tripped.
Proceed as follows to replace the mains fuse:
• Turn off the power supply and disconnect all connection cables from the device
and the power plug from the power socket.
• Now press the rear of the fuse holder in somewhat with a suitable straight-edge
screwdriver and turn it anticlockwise outward one quarter of a turn (bayonet
catch).
• Replace the defective fuse with a new fine-wire fuse (5 x 20 mm) of the same type
and rated current:
T1.6A / 250V (slow burning).
• Rotate the fuse insert clockwise while pressing it back into the fuse holder.
Troubleshooting
By purchasing the power supply you have acquired a product that is reliable and
operationally safe.
However, problems and malfunctions may occur.
For this reason we want to describe how to troubleshoot potential malfunctions:
Do not fail to heed the safety instructions!
Fault
The power supply unit does
not work
Connected consumers do
not work
Periodically check the technical safety of the device, e.g. check for damage to the
housing etc.
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Possible cause
Do characters appear in the display?
Check the mains voltage (you may also want
to check the mains fuse in the device or the
line circuit breaker).
Has the correct voltage been set?
Is the polarity correct ?
Is the power supply unit overloaded ?
Check the technical data of the consumers.
Is the current limitation active ?
• In schools and training centres as well as at hobby and DIY workshops, the use of
power supplies must be supervised by adequately trained personnel in a responsi-
ble manner.
• Please make sure by all means that your hands, your shoes, your clothing, the flo-
or and the power supply are dry.
• Potentially lethal voltages (> 35 VDC) are generated when the outputs of one or
more power supplies are switched in series.
• Before opening it, disconnect the device from all voltage sources.
• Capacitors in the device may still be charged, even if the device has been dis-
connected from all voltage sources.
• Do not switch the power supply on immediately after it has been taken from a cold
to a warm environment. Under adverse conditions, the resulting condensation could
destroy the device. Allow the device to reach room temperature before switching on.
• The power supply generates heat during operation. Make sure it is adequately ven-
tilated. Do not cover the ventilation apertures of the device!
• Do not leave mains power supplies and the connected consumers in operation
unattended.
• Use only fuses of the type and rated current specified. It is absolutely impermissi-
ble to use repaired fuses.
• Avoid the use of uninsulated metallic cables.
• Power supply units are not designed for use on human beings or animals.
• If you have reasons to assume that safe operation is no longer possible, immedia-
tely take the device out of operation and secure it against inadvertent operation.
Reasons to assume that safe operation is no longer possible include:
- the device shows signs of visible damage
- the device no longer functions and
- has been stored for long periods under unfavourable conditions or
- has been subjected to considerable stress in transit.
• You should also heed the additional safety instructions in each chapter of these
operating instructions as well as in the operating instructions of the connected
devices.

Functional description

The power supply unit PS 303 Pro has two independent extra-low voltage outputs
with controllable output voltages.
The DC outputs of the power pack are dc-isolated and feature a fuse disconnector to
the mains voltage.
The output voltage of "OUTPUT A" can be fine and coarse adjusted. The output cur-
rent can be limited. The voltage and the current are rendered in displays "1" and "2".
By pressing button "6", the output voltage of "OUTPUT B" can be read in display "1"
whilst the voltage is adjusted with controller "7".
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