Under Voltage Limit (Uvl); Setting The Uvl Level; Foldback Protection; Setting The Foldback Protection - TDK-Lambda Genesys GEN8-300 User Manual

5.4 UNDER VOLTAGE LIMIT (UVL)

The UVL prevents adjustment of the output voltage below a certain limit.The combination of UVL
and OVP functions, allow the user to create a protection window for sensitive load circuitry.

5.4.1 Setting the UVL level

Setting the UVL can be made when the power supply output is Enabled (On) or Disabled (Off). To set
the UVL level, press the OVP/UVL button TWICE, so that the CURRENT meter shows "UUL". The
VOLTAGE meter shows the UVL setting level. Rotate the VOLTAGE encoder knob to adjust the UVL
level. The display will show "UUL" and the setting value for 5 seconds after the adjustment has been
completed and then will return to it's previous state.
UVL setting values are limited at the maximum level to approximately 95% of the Output Voltage
setting. Attempting to adjust the UVL above this limit will result in no response to the adjustment
attempt. The minimum UVL setting is zero.

5.5 FOLDBACK PROTECTION

Foldback protection will shut down the power supply output if the load current exceeds the current limit
setting level. This protection is useful when the load circuitry is sensitive to an over current condition.

5.5.1 Setting the Foldback protection

To arm the Foldback protection, the FOLD button should be pressed so that the FOLD LED illuminates.
In this condition, transition from Constant Voltage to Constant Current mode will activate the Foldback
protection. Activation of the Foldback protection disables the power supply output, causes the ALARM
LED to blink and display " Fb" on the VOLTAGE meter.

5.5.2 Resetting activated Foldback protection

There are four methods to reset an activated Foldback protection.
1. Press the OUT button. The power supply output is enabled and the Output Voltage and current
will return to their last setting. In this method, the Foldback protection remains armed, therefore if
the load current is higher than the current limit setting, the Foldback protection will be activated
again.
2. Press the FOLD button to cancel the Foldback protection. The power supply output will be disabled
and the VOLTAGE display will show "OFF". Press the OUT button to enable the power supply output.
3. Turn the power supply output Off and then On using the SO control (refer to sect. 5.7). In this method
the foldback protection remains armed, therefore if the load current is higher than the current limit
setting the Foldback protection will be activated.
4. Turn the power supply Off using the AC On/Off switch, wait until the front panel display turns Off,
then turn the unit back ON again. The power supply output is enabled and the Output Voltage and
Current will return to their last setting. In this method, the Foldback protection remains armed,
therefore if the load current is higher than the current limit setting, the Foldback protection will be
activated again.

5.6 OUTPUT ON/OFF CONTROL

The Output On/Off enables or disables the power supply output. Use this function to make adjustments
to either the power supply or the load without shutting off the AC power. The Output On/Off can be
activated from the front panel using the OUT button or from the rear panel J1 connector.The OUT
button can be pressed at any time to enable or disable the power supply output. When the output is
disabled, the output voltage and current fall to zero and the VOLTAGE display shows "OFF".

5.7 OUTPUT SHUT-OFF (SO) CONTROL VIA REAR PANEL J1 CONNECTOR

Contacts 2,3 and 15 of J1 (Fig.4-2, Item 5) serve as Output Shut-Off (SO) terminals. The SO terminals
accept a 2.5V to 15V signal or Open-Short contact to disable or enable the power supply output. The
SO function will be activated only when a transition from On to Off is detected after applying AC power
to unit. (Thus , in Auto-Restart mode, the output will be enabled after applying AC power, even if SO is in
Off level.). After On to Off transition is detected, the SO will enable or disable the power supply output
according to the signal level or the short/open applied to J1. This function is useful for connecting power
supplies in a "Daisy-chain" (refer to section 5.16). The SO control can be used also to reset the OVP
and Fold Protection. Refer to sect. 5.3 and 5.5 for details.
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