Overvoltage Protection - Ametek SPS A Series Operation Manual

Operation

3.3.5 OVERVOLTAGE PROTECTION

The Overvoltage Protection (OVP) function allows the supply to shutdown
the output when it exceeds a preset voltage. This may be used to protect
sensitive circuits or loads from damage caused by an excessive voltage
on the output of the supply.
To verify OVP operation:
1. Make sure there is nothing connected across the output terminals.
2. Rotate the Current control knob about ½ turn clockwise (this sets
the current limit at a nominal setting above 0 Amps)
3. Switch the power supply on.
4. Press and hold the Set/Reset Overvoltage Protection pushbutton
on the front panel and observe the reading on the voltage display.
This is the present setting of the OVP limit. The factory default
setting is approximately 110% of the maximum rated output of the
supply.
5. While holding down the Set/Reset button, use a small adjustment
screwdriver to adjust the OVP setting by turning the 4-turn
recessed adjustment potentiometer counterclockwise.
As you adjust the potentiometer the reading on the voltage display
should decrease (increase as you adjust in a clockwise direction).
6. Set the OVP to about 80-90% of the maximum rated output
voltage and note the OVP voltage value.
7. Release the Set/Reset pushbutton.
8. Rotate the Voltage knob clockwise until the voltage display
indicates you are about 2-3% below the OVP voltage value noted
above.
9. Slowly continue to increase the output of the supply until you
exceed the value of the OVP setting.
10. Check that the OVP LED lights and that the output of the supply
powers down to 0 volts (as indicated on the Voltage display).
11. Turn the Voltage knob fully counterclockwise, then press and hold
the Set/Reset pushbutton until the OVP LED is no longer lit.
12. Reset the OVP setting as appropriate for your application per
steps 4 and 5 above. If you do not choose to use OVP, then the
OVP adjust may be set fully clockwise to approximately 110% of
the rated output voltage of the supply.
If OVP mode did not function as indicated above, recheck your setup and
perform the check again. If the function continues to fail, contact the
factory for assistance.
3-12
AMREL SPS-A Series
M550129-01 Rev A