Kussmaul 091-141 User Manual

FILE: IM_091-141_Rev_B

DATE: 10-02-03

INSTRUCTION MANUAL

LOAD MANAGER P

A battery protector for vehicles with equipment that

Is operated with the engine not running

MODEL# 091-141

INPUT: 12 Volts D.C.

MODEL# 091-141-24

INPUT: 24 Volts D.C.

3 YEAR WARRANTY

INTRODUCTION

The model 091-141 LOAD MANAGER P is designed to disconnect loads when
the battery voltage drops below a certain threshold. In addition a "Shutdown
Timer" is provided so that the load is disconnected 1 to 2 hours after the engine
is shutdown. This provides the ideal control for the computer or radio in police
cars, rescue vehicles, command vehicles or any application where these devices
might be used with the engine not running. If the operator forgets to shut down
the computer or radio, the battery is protected, as the Load Manager P will turn
off the power before the battery is drained.

12VDC Operation:
The factory pre-set voltage for shutdown is 11.0 volts, but can be
potentiometer adjusted up to 12.85 volts. The factory pre-set shutdown
time is 1 hour (when engine is not running). This time can also be
potentiometer adjusted up to 2 hours.

24VDC Operation:
The factory pre-set voltage for shutdown is 22.0 volts, but can be
potentiometer adjusted from 21.25 to 24.75 volts. The factory pre-set
shutdown time is 1 hour (when engine is not running). This time can also
be potentiometer adjusted up to 2 hours.

Shutdown Timer:
Enabled (factory default) when diode CR4 is installed on Printed Circuit
Board Assembly (refer to Figure 3). Disabling the Shutdown Timer by
removing CR4 will allow load power supply regardless of engine
running/not running status. The load will, however, still be managed as a
function of vehicle battery voltage per voltage shutdown described above.
The Load Manager Model Number will be followed by "DIS" if the Shutdown
Timer is disabled at the factory per customer order.

PRINCIPLES OF OPERATION

The Load Manager P is basically a low voltage disconnect which removes power
from the load when the voltage sensed drops below the preset threshold of 11.0
volts for 12VDC operation and 22.0 volts for 24VDC operation. A starter override
is provided to prevent disabling the load while the engine is cranking. This
eliminates re-booting the computer if cranking the engine drops the battery
voltage below the threshold. When the device detects that the engine is not
running a timer is started. After the set time has elapsed the load will be
deenergized. If during the timing cycle, the battery voltage drops below its set
point, the load will be immediately deenergized. Starting the engine at any time
during the timing cycle will reset the timer. A block diagram appears in figure 1.

FACTORY ADJUSTED

TO 1 HOUR

ENGINE

OFF

SENSOR

V

Bat

PRE-SET

ADJUST

TRIMMER

TIMER

1 HOUR

2 HOURS

VOLTAGE

PRE-SET

ADJUST

TRIMMER

VOLTAGE

DETECTOR

TIME

AND ENGINE IS “OFF”

TO

>

T

T

IF TRUE

Sp

STARTER

SWITCH “ON”

V

<

V

IF TRUE

Bat Sp

Figure 1

BLOCK DIAGRAM, LOAD MANAGER P

TRUE WHILE
ENGINE IS
“CRANKING”

POWER

RELAY

IF THIS LINE IS
TRUE, THEN THE
POWER RELAY
IS ENERGIZED