When the output is tripped the OUTPUT lamp will still be ON but the displays will show ‘OP trip’
and the UNREG lamp will also light. Turn the output off; the trip message should be replaced with
the normal preset V and I readings. When the cause of the trip has been removed the output can
be switched on again.
Even with the output off the load is still connected to the power supply output stage. Do not apply
external voltages in excess of 70V to the power supply terminals or damage may result.
The output is protected from reverse voltages by a diode; the continuous reverse current must not
exceed 3 Amps, although transients can be much higher.
Over-temperature Protection
Sensors on both the secondary heatsinks will detect over-temperature due to blocked air flow, fan
failure or other circuit fault. Over-temperature will shut down the output (the display will read 0
Volts and 0 Amps if the output is ON) though the output ON lamp will remain lit. The output will
remain shut down even after the heatsinks have cooled down. When the cause of the over-
temperature has been removed and the heatsinks have cooled to normal working temperatures
the output can be reset by turning the POWER switch to standby ( ) then on (
l ) again.
Maintenance
The Manufacturers or their agents overseas will provide repair for any unit developing a fault.
Where owner wish to undertake their own maintenance work, this should only be done by skilled
personnel in conjunction with the service manual which may be purchased directly from the
Manufacturers or their agents overseas.
Fuse
The correct fuse type is:
15 Amp 250V HBC time-lag, 1¼” x ¼”
Make sure that only fuses of the required rated current and specified type are used for
replacement. The use of makeshift fuses and the short-circuiting of fuse-holders is prohibited.
To replace the fuse, first disconnect the instrument from the AC supply. Remove the 6 cover
securing screws and lift off the cover. Replace the fuse with one of the correct type and refit the
cover.
Note that the main function of the fuse is to make the instrument safe and limit damage in the
event of failure of one of the switching devices. If a fuse fails it is therefore very likely that the
replacement will also blow, because the supply has developed a fault; in such circumstances the
instrument will need to be returned to the manufacturer for service.
Cleaning
If the PSU requires cleaning use a cloth that is only lightly dampened with water or a mild
detergent. Polish the display window with a soft dry cloth.
WARNING! TO AVOID ELECTRIC SHOCK, OR DAMAGE TO THE PSU, NEVER ALLOW
WATER TO GET INSIDE THE CASE. TO AVOID DAMAGE TO THE CASE OR DISPLAY
WINDOW NEVER CLEAN WITH SOLVENTS.
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