AMETEK SGA Series - Manual (Page 63)

Sorensen SGA Series Operation
M550129-01 Rev AG 3-13
3.3.4 OVERVOLTAGE PROTECTION
The Overvoltage Protection (OVP) function allows the supply to shutdown the
output, if it were to exceed 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. The Overvoltage Protection (OVP) could be set
either with the front panel potentiometer or by the remote analog OVP
programming input; see Section 3.7. To verify OVP operation, follow the
steps below:
1. Make sure there is nothing connected across the output terminals.
2. Rotate the Current control knob about 1/2 turn clockwise (this adjusts
the current setting to a value above zero to ensure ability to supply
current).
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 voltage of the
supply.
5. While holding down the Set/Reset button, use a small flat-blade
adjustment screwdriver to adjust the OVP setting by turning the multi-
turn recessed adjustment potentiometer counterclockwise. As the
potentiometer is adjusted, the reading on the voltage display should
decrease (increase, if adjusted in a clockwise direction).
6. Set the OVP to about 80-90% of the maximum rated output voltage
and record the OVP voltage value.
7. Release the Set/Reset pushbutton.
8. Rotate the Voltage knob clockwise until the voltage display indicates
about 2-3% below the OVP voltage value recorded above.
9. Slowly continue to increase the output of the supply until the value of
the OVP setting is exceeded.
10. Check that the OVP LED lights and that the output of the supply
powers down to 0 V (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.