Kussmaul 091-139-2-12 User Manual

FILE: 091-139-002

REV.A: 2/24/04

DATE: 04-23-01

INSTRUCTION MANUAL

AUTO ISOLATOR I

AN AUTOMATIC LOSSLESS BATTERY ISOLATOR

FOR DUAL BATTERY SYSTEMS

MODEL# 091-139-2-12

BATTERY VOLTAGE: 12 VDC

OUTPUT: 12 VOLTS, 3 AMPS

BATTERY PARALLELING SOLENOID: 200 AMPS

3 YEAR WARRANTY

INTRODUCTION

The Model 091-139-2-12 AUTO ISOLATOR I system is a lossless isolator
replacement for the conventional diode isolator. Designed to be installed in a
vehicle with one or more Main batteries that must be isolated from one or more
auxiliary batteries. The system consists of a voltage detector and controller
Model 091-139-CONT-12 and a separate 200-ampere rated solenoid, Model
091-139-SOL-12HO for switching the batteries. In addition to maintaining battery
isolation the AUTO ISOLATOR I may parallel the batteries on engine starting if
the auxiliary battery has sufficient charge to assist in the cranking. A block
diagram of the system appears in figure 1.

STARTER

PUSH BUTTON

STARTER

ISOLATOR

ALTERNATOR

MAIN BATT ERY SENSE

AUXILIARY BATTERY SENSE

POWER

IGNITIO N

SWITCH

PARALLELING

SOLENOID

DRIVER

SOLENOID

STARTER

SOLENOID

MAIN

BATTERY

AUXILIARY

BATTERY

MAIN
BATTERY
VOLTAGE

DETECTOR

AUX.

BATTERY
VOLTAGE

DETECTOR

TIMER

Figure 1

Block Diagram

SYSTEM OPERATION

The system receives its power from the ignition switch. With the switch “OFF” all
the power is removed from the system and the solenoid is deenergized.

As soon as the operator turns the ignition “ON”, the system is powered and
detects the voltage of the main and auxiliary batteries. If the auxiliary battery
voltage is 12.4 volts or greater, (indicating sufficient charge) cranking the engine
will cause the paralleling solenoid to be energized. A 10-second timer will
maintain the paralleling solenoid if the engine doesn’t start immediately and must
be cranked a second time. When the engine starts the alternator output raises
the battery voltage. This increase in voltage is detected and the paralleling
solenoid is held energized charging both batteries.

If when the engine is started the auxiliary battery voltage is below 12.0 volts the
paralleling solenoid is not energized while cranking. As soon as the engine
starts, the alternator raises the main battery voltage and the solenoid is
energized charging both batteries.

Upon engine shutdown the ignition switch is placed in the “OFF” position. Power
is removed from the Auto Isolator and the solenoid is deenergized.