Kussmaul Electronics 091-108-012 - Manual (Page 2)

INTRODUCTION
The 091-108-012 OVER VOLTAGE RELAY is a device that continuously monitors the voltage of the
battery. The unit is factory set to actuate at 17 volts, and reset at 14 volts but may be adjusted to other
voltages. The output relay is capable of switching 30 amperes, and both a “normally open” and
normally closed” contacts are provided.
Connect the OVER VOLTAGE RELAY to the battery, the load and the fuse as illustrated in figure 1.
This is a typical circuit. Other circuit configurations are possible. It is always necessary to connect
the Bat+ and Bat- terminals to that point at which the voltage is to be sensed.
ADJUSTMENT
The factory setting for the OVER VOLTAGE RELAY is 17.0 volts. Field adjustment of the set point
is possible. To do this, remove two screws holding down the cover. Note the position of the voltage
adjustment trimmer R5. This is the 17-volt setting. To decrease the voltage turn counter clockwise.
To increase the voltage turn clockwise. Two indicator LED’s are provided adjacent to the terminal
strip. When the green LED is lit, the voltage sensed is normal. When the red LED is lit, the voltage
is above the set point. The voltage detector can be tested by gradually raising the system voltage while
simultaneously measuring the voltage applied to the input terminals with a precise voltmeter and
noting the voltage at which the red LED turns “ON”.
The 091-108-012 OVER VOLTAGE RELAY contains an adjustable high hysteresis feature. With the
normal trip point set to 17.0 volts, the hysteresis circuit maintains the relay energized until the voltage
decreases below 14.0 volts. This assures that the loads being controlled are not energized until the
sensed voltage reaches 14.0 volts. This limits the ON/OFF cycling of the load. The hysteresis may
be adjusted using trimmer R15. Turning R15 CCW will decrease the hysteresis while turning CW will
increase. Unless absolutely necessary it is recommended that the hysteresis remain at the factory
setting.
INSTALLATION