Vogt P-24AL, Руководство по обслуживанию

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P24AL & P34AL Service Manual
OPTIONS AND ACCESSORIES
12/2016
10-8
Display of fault memories (MEM flashes). Pressing up or down displays the last fault conditions
that took the unit off line. The first 25 faults are recorded. The top number displayed represents the
fault memory. The middle number represents the total number of faults that have occurred since the
fault memory was cleared. To clear the memory, press and hold the up and down keys until the
display is cleared.
NOTE: If you press SELECT and do not change a parameter by pressing the up or down arrow keys,
the DTP-3 automatically returns to displaying the line voltage in a few seconds.
The new settings are saved in permanent memory when the display returns to displaying the line
voltage. The new settings may be verified by pressing the select button to sequence through the
various parameters.
To prevent tripping on a 1-volt change, the DTP-3 automatically calculates cut-in voltages for the
return from undervoltage conditions. The cut-out voltage is always based on user voltage and
tolerance settings, while the cut-in voltage is 3% closer to the nominal voltage setting. This quality
is sometimes referred to as hysteresis. This is to help reduce oscillation that may occur on weak
power distribution system. When the load is switched off due to undervoltage, the line voltage will
increase. Without the hysteresis, the monitor would switch the load back on, the line voltage would
again drop, and cause a continuous on-off-on cycling.