Powerten D3 Series, Operation Manual

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8. Adjust potentiometer R40 of converter assembly being calibrated until
DMM across external current shunt indicates one-third the full-rated
output current for 15 kW power supply models.
9. Remove prime power from power supply and wait 3 minutes
(minimum) for filter capacitors to discharge.
10. Repeat steps (1) through (9) for the balance of converter assemblies
A3 through A5.
4.2.4 Control Assembly Calibration
In this section refer to Figure 4-6 for locations of assemblies and potentiometers.
Voltage Reference
The voltage reference is provided by an adjustable current regulator Q1
and associated components. To calibrate for the 1 mA programming
coefficient (constant voltage), the following sequence is recommended.
For J1 and J2, refer to the D-shell connectors on the rear panel.
1. Set front panel current control fully counterclockwise.
2. Connect a precision DMM to J1-21(VP RES) with reference to
J1-24(COM). Set DMM to DC milliamps and 2 milliamps range.
3. Apply power to power supply, and push the front panel switch to the
ON position.
4. Adjust R47 for 1.000 milliamps on DMM.
5. Remove power from power supply.
Current Reference
The current reference is a precision current source consisting of Q2 and
associated components. Calibration is accomplished by adjusting R50.
The following sequence is recommended. For J1 and J2, refer to the D-
shell connectors on the rear panel.
1. Set front panel voltage control fully counterclockwise.
2. Connect a precision DMM to J1-22(IP RES) with reference to
J1-24(COM). Set DMM to DC milliamps and 2 mA range.
3. Apply power to power supply, and push the front panel switch to the
ON position.
4. Adjust R50 for 1.000 milliamps on DMM.
5. Remove power from power supply.
Voltage Zero Calibration
The voltage control circuit (U11-A) zero is adjusted by R39. The following
sequence is recommended. For J1 and J2, refer to the D-shell
connectors on the rear panel.
1. Connect a jumper (short circuit) between J1-8(V SET) and J1-
6(COM).
2. Connect DMM across CR7. Set DMM to read DC volts and
approximately 200 millivolt range.
M550001-01 4-9