83-517-000 Rev.
A
44
4. Adjustment resolution can be set to
COARSE
or
FINE
adjustment. Press the
FINE
button to select between
the
COARSE
and
FINE
resolution. The
FINE LED
illuminates when the adjustment resolution is set to
FINE
.
Automatic Crossover
5.2.3
If the power supply operates in Constant-Voltage mode, while the load current is increased to greater than the
Output current limit setting, the power supply will automatically switch to Constant-Current mode. If the load is
decreased to less than the Output current limit setting, the power supply will automatically switch back to
Constant-Voltage mode.
5.3
OVER-VOLTAGE PROTECTION (OVP)
The OVP circuit protects the load in the event of a remote or local programming error or a power supply failure.
The protection circuit monitors the voltage at the power supply sense points and thus provides the protection
level at the load. Upon detection of an Over-Voltage condition, the power supply output will shut down.
Setting the OVP level
5.3.1
The OVP can be set when the power supply output is Enabled (
ON
) or Disabled (
OFF
). To set the OVP level,
press the
OVP/UVL
button, so that the
CURRENT
meter displays
“
OUP
”. The
VOLTAGE
meter will display the
OVP
setting level. Rotate the
VOLTAGE
encoder knob to adjust the
OVP
level. The
CURRENT
meter will show
“
OUP
” and the
OVP
setting value for 5 seconds after the adjustment has been completed, and will then return to
its previous operating state.
The minimum
OVP
setting level is approximately 105% of the
set Output voltage, or the value in Table 7-6, whichever is
higher. The maximum
OVP
setting level is shown in Table 5-1.
To preview the
OVP
setting, press the
OVP/UVL
button so that
the
CURRENT
meter displays
“
OUP
”. At this time, the
VOLTAGE
meter will display the
OVP
setting. After 5 seconds,
the front panel display will return to its previous state.
Table 5-1: Maximum OVP setting levels
Activated OVP protection indications
5.3.2
When the Output
OVP
is activated the power supply output shuts down. The
VOLTAGE
meter display
s “
OUP
”
and the
ALARM LED
blinks.
Resetting the OVP circuit
5.3.3
To reset the OVP circuit after it activates:
1. Reduce the power supply Output voltage setting below the
OVP
set level.
2. Ensure that the load and the sense wiring are connected properly.
3. There are four methods to reset the
OVP
circuit.
3.1 Press the
OUT
button.
3.2 Turn the power supply
OFF
using the AC
ON/OFF
switch, wait until the front panel display turns
OFF
,
then turn the power supply
ON
using the AC
ON/OFF
switch.
3.4 Turn the power supply output
OFF
and then
ON
using the
SO
control (refer to Section 5.7). In this
method the power supply should be set to
Auto-Restart
(
AUTO
) mode.
3.4 Send an
“
OUT1
”
command via the RS-232/RS-485 serial communication port.
5.4
UNDER VOLTAGE LIMIT (UVL)
The Output
UVL
prevents adjustment of the Output Voltage below a user-set limit. The combination of Output
UVL
and OVP functions allow the user to create a protection window for sensitive load circuitry.
Setting the Output UVL level
5.4.1
Setting the Output
UVL
can be made when the power supply output is Enabled (
ON
) or Disabled (
OFF
). To set
the Output
UVL
level, press the
OVP/UVL
button
TWICE
so that the
CURRENT
meter displays
“
UUL
”. The
VOLTAGE
meter will also display the
UVL
setting level. Rotate the
VOLTAGE
encoder knob to adjust the
Output
UVL
level. The
CURRENT
meter will display
‘
UUL
” and the
UVL
setting value for 5 seconds after the
adjustment has been completed and will then return to its previous operating state. Output
UVL
setting values
are limited at the maximum level to approximately 95% of the Output voltage setting. Attempting to adjust the
Output
UVL
above this limit will result in no response to the adjustment attempt. The minimum Output
UVL
setting is zero.
Model
Max.
OVP
Model
Max.
OVP
8V
10V
16V
20V
30V
40V
10.0V
12.0V
19.0V
24.0V
36.0V
44.0V
60V
80V
100V
150V
300V
600V
66.0V
88.0V
110.0V
165.0V
330.0V
660.0V
