Adjusting The Voltmeter Accuracy - HindlePower AT30 SERIES Operating And Service Instructions

2.3.7. Adjusting the Voltmeter Accuracy

The AT30 voltmeter is adjusted at the factory to display the actual dc
output voltage within ±0.25%. The meter must be recalibrated if any
component is replaced that affects meter accuracy, such as the Main
Control PC Board (A1) or Scaling Resistor (R4). This adjustment
procedure is different from all others, because the meter reading remains
constant while the output voltage of the AT30 changes. Do this
adjustment with a fully charged battery and no load connected.
• Enter Edit Mode to adjust the AT30 float voltage to the desired
value. See Section 2.3.2 on page 31 for adjusting float voltage.
• After entering the float voltage, exit Edit Mode by pressing the
EDIT/ENTER key four (4) times until the AT30 returns to normal
operation. If you do not press any front panel key for 25 seconds,
Edit Mode ends automatically, and any change made to the last
setting is not saved.
• After successfully exiting Edit Mode, you may adjust the
voltmeter accuracy. Press and hold the UP key, then press the
EQLZ MTHD key.
• The DC VOLTS METER MODE indicator will light, and the
front panel display flashes the dc output voltage reading.
• Measure the AT30 dc output voltage using a meter accurate to
±0.25% or better.
• While watching the external meter connected to the AT30 output
(not the front instrument panel display), press the UP or DOWN
key until the actual (meter) output voltage matches the float setting
on the front panel display.
Allow 1-2 seconds for the dc output voltage to
stabilize each time you press the
• Each time you press UP or DOWN, the AT30 dc output voltage is
raised or lowered by a small amount.
• Continue to press UP or DOWN until the actual (measured) dc
voltage agrees with the front panel display reading, within ±0.25%.
• When you are finished adjusting the output voltage, the AT30 waits
5 seconds before the front panel display automatically returns to
normal operation.
OPERATING THE AT30
NOTICE
UP
or key.
DOWN
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