ADJUSTMENT INSTRUCTIONS FOR MODEL A-51
The inverter is factory tested and adjusted so that
no
field
adjustments
are
necessary
upon
installation.
Should
field
adjustments
become
necessary, apply the following:
Two potentiometers are provided for adjusting
the inverter.
P2 Under voltage cut-out
P3 Over voltage cut-out
UNDER VOLTAGE CUT-OUT
POTENTIOMETER P2
Should the d-c input voltage drop below the voltage
setting
of
this
potentiometer,
the
inverter
will
automatically turn off. The inverter will automatically turn
on again, after a time delay, when the input voltage is
restored to normal. The factory low d-c voltage cut-out
.point is set at 1.75 volts per cell for lead acid batteries
and 1.1 volts per cell for nickel cadmium batteries. If the
inverter does not start, due to misadjustment of low
potentiometer setting, proceed as follows:
1. Check input voltage for normal (2.17 Lk, 1.4 NC)
input voltage.
2. Turn potentiometer P2, fully counterclockwise.
3. Turn switch on, start inverter.
4. Lower d-c input (apply load or reduce cells) until
the low voltage setting is reached (1.75 volts per
cell, lead acid, 1.1 volts per cell, nickel
cadmium).
5. Raise the cut-out voltage setting by turning
potentiometer P2 in the clockwise direction.
When the cut-out voltage is reached, the inverter
will turn off.
6. When the voltage returns to normal, the inverter
will automatically turn on after a two second time
delay.
7. The adjusting screw should be resealed to
prevent further movement.
OVER VOLTAGE CUT-OUT
POTENTIOMETER P3
The over voltage cut-out potentiometer is located on the
over and under voltage protection printed circuit card
AC3. This potentiometer is located to the right of the
under voltage potentiometer (see schematic).
The over voltage cut-out will turn the inverter off should
the d-c input voltage exceed the. high voltage setting.
Potentiometer P3 is factory set at 2.5 volts per cell for
lead acid batteries and 1.65 volts per cell for nickel
cadmium batteries.
Adjusting instructions are as follows:
1. Check input voltage for normal output.
2. Turn adjusting screw on potentiometer P3 on PC
card AC3, clockwise. This will raise the voltage
cut-out point.
3. Turn switch on, start inverter.
4. Raise the d-c input voltage. Adjust the charger
voltage to 2.5 volts per cell (lead acid), 1.65 volts
per cell (nickel cadmium).
5. Turn
the
potentiometer
adjusting
screw
counterclockwise to lower the cut-out voltage
until the inverter shuts off.
6. The inverter will automatically turn on when the
voltage is returned to normal after a two second
time delay.
7. Reseal the adjusting screw to prevent further
movement.
7
