AMETEK APG-XT - Manual (Page 35)

Section 4. Calibration
Over Voltage Protection (OVP) Calibration
53
Over Voltage Protection (OVP) Calibration
1. Connect the unit as for voltage mode calibration. See Figure 4.1 . See
“Calibration Setup” on page 48 , step 4. (Optional step.)
2. Program the OVP setting to 50% of the full scale voltage by sending the
following command string from the computer:
OVSET20 (for 1kW Model 40-25)
3. Program the output voltage to about 40% of the OVP set value by sending:
VSET16;ISET25 (for 1kW Model 40-25)
4. Increment the programmed output voltage from the computer until the OVP
fires. The red OVP LED on the front panel will light up.
5. Clear the supply settings by sending:
CLR
6. and reset the OVP condition with:
RST
7. The OVP trip point is in specification if the meter value shown when OVP fires
is within the total of the set trip point ± the OVP program accuracy specification
for the power supply model. See
Section 1 .
Example: 20V ± 400mV (for 1kW Model 40-25)
8. If the OVP trip point was out of specification, adjust potentiometers R19
(OVPREF, coarse adjustment) and R23 (OVPOFF, fine adjustment). Repeat
steps 2 to 5 until the unit operates within specified values again.
9. Check for linearity by testing the OVP trip point at 10% and 90% of full scale
voltage.