AMETEK DLM 600W Series - Manual (Page 54)

DLM 600W Series
M362161-01 K 3-8
3.5 OVP Operation
The OVP monitor provides protection from overvoltage conditions that could be
generated at the load due to improper adjustment of the output voltage or malfunction of
the unit. Provisions are available to set the OVP threshold either with the front panel
controls or remotely through the analog interface (or, through the optional GPIB
interface).
The monitor measures the output voltage at the point where the sense leads are
connected: either internally at the output terminals or at the remote sense leads,
depending on which method of sensing is selected. If remote sensing is selected, a
secondary monitor measures the voltage at the output terminals, in addition to the
primary monitor measuring the load voltage. This provides protection in case the
remote sense leads are disconnected.
When the OVP is tripped, the output converter is turned off and the output capacitors
are discharged with a downprogrammer. In addition, the front panel OVP indicator is
turned on.
3.5.1 Adjustment of OVP Threshold
Use the following procedure to set the OVP threshold:
1. Turn the front panel POWER switch to the ON position and the OUTPUT switch to
the OFF position.
2. Press in the V/I PREVIEW switch to display the programmed setting of the output
voltage and current. Set the displayed values to the desired output voltage and
current.
3. Press in the OVP PREVIEW switch to display the programmed setting of the OVP
threshold. Ensure that the OVP setting exceeds the setting of the output voltage;
otherwise, the OVP will be tripped as soon as the POWER switch is turned ON.
4. OVP operation is verified as follows: set the OVP threshold to less that full scale
output voltage rating of the power supply; set the output voltage to less than the
OVP threshold; turn POWER switch ON; adjust output voltage so that OVP
threshold is exceeded; output will shut down and OVP indicator will be turned on
when OVP threshold is reached.