MAINTENANCE & TROUBLE SHOOTING
ES300
10 / 13
DELTA ELEKTRONIKA B.V.
rev. Sept. 2019
4
MAINTENANCE & TROUBLE
SHOOTING
4.1 GENERAL
The ES-series power supplies normally need no maintenance
or calibration. Only care must be taken that the cooling of the
unit is not obstructed.
If required, the full scale indication of the V-meter can be
calibrated with trimpotmeter R480, the I-meter with R490.
4.2 NO OUTPUT (normal operation)
Remove load from output.
Check position of prog. switches at the rear panel, they
should be on MANUAL.
Switch on unit.
Turn both the CV and CC potentiometer a few turns clock-
wise. A voltage should be present on the output.
4.3 PROGRAMMING DOES NOT WORK OK
Check position of prog. switches at rear panel.
The unit works OK in manual control, but in programming
mode the output voltage / current has a large error.
Probably the fuse in series with Ø (pin 1) of prog. connector
tripped, the fuse (F400 = 650 mA) is a self-resetting type.
To check the fuse (F400) measure the voltage between Ø
and the minus output, during the fault condition. The voltage
should only be a few mV, a high voltage means that an
unwanted current is flowing through pin 1 of the prog.
connector.
Please check why current is flowing through pin 1 (see also
next paragraph and fig. 4 - 1).
4.4 PROGRAMMING OFFSETS
Unwanted offsets in the programming can be caused by
earth loops.
Fig. 4 - 1 shows a typical earthing problem. In case the load
has a connection to earth and the programming source as
well, problems could occur. Improper choice of the earthing
point of the load can give a voltage drop of ΔV1.
Connecting the minus or zero to a separate earth connection
can give a voltage drop of ΔV2. Because the internal wires of
the programming input are thin, the voltage drops ΔV1 and
ΔV2 will be accross the internal wiring as well. Resulting in a
error voltage in series with the programming voltage.
The best solution for this is using a floating programming
source with the help of the ISO AMP MODULE or a floating
load.
4.5 STATUS OUTPUT FAILS
Check fuse F401 in series with Ø (pin 8 of programming
connector). To check the fuse measure the voltage between
Ø and the minus DC Power output, a high voltage means too
much current is flowing through the fuse. F401 = 650 mA -
self resetting.
4.6 MASTER / SLAVE PARALLEL PROBLEMS
Accidental interruption of a minus lead of a unit during
operation will cause fuse F400 to blow. To check the fuse,
measure the voltage between Ø (pin 1 of prog. conn.) and the
minus DC power output, the fuse is a self resetting type.
F400 = 650 mA self resetting. If the voltage is too high, too
much current is flowing through it.
Check link between pin 9 and 11 on the programming
connector of the slaves.
4.7 NO LEDS on.
Overheating can be the cause, cooling down will reset the
thermal protection.
Check input power.
Check fuses inside unit.
F400
Warning!
0Vprog. and Minus DC power
are internally connected.
