with both Switches and Isolators

BATTERY CHARGER SYSTEMS with Switches, Isolators and Battery Chargers

This pamphlet has been prepared to show just a few of the many and varied uses for Guest Battery Selector Switches, Battery Isolators, and Battery Chargers. It must be remembered that, In all of these diagrams, wire sizes must be those as suggested by the individual equipment manufacturers. It is also important to conform to the proper wiring standards and regulations where they apply.

48 Elm St, Meriden. Connecticut 06450 USA      Tel. (203) 238-0550


#2100, #2101, #2300A. #3100. #3101. #3200. #3201

Guest selector switches are "make-before-break'' single pole. triple-throw switches that permit the selection between either of two batteries or banks of batteries. operation of both batteries or banks of batteries in parallel. or complete disconnect of both batteries or banks of batteries. The switches are rated as follows at   6. 12. 24 or 32 volts:
             Momentary  Continuous         Momentary  Continuous
         Model    Amps   Amps         Model     Amps   Amps
          2100       345       230           3100        345       230
          2101       345       230           3101        345       230
        2300A      600       360           3200        345       230
                                                       3201        345       230     
Model 2100. 2300A.3100 and 3200 switches feature an alternator field disconnect which interrupts the alternator field when the switch is turned to the "off" position, thus preventing electrical surges in the armature circuit which might burn out the alternator diodes or ancillary equipment. Models 2101. 3101 and 3201 do not include this feature and should never be turned to the "off' position with engine running.

These switches are designed as disconnect switches and are not to be used as load-breaking devices. If switch is used as load-breaking device in emergency situation (e.g.. starter malfunction), switch should be replaced to avoid possible future failure.

Mounting:  Switch should be located as close to (within 40") the  batteries as possible. The battery and starter cable should be as short as possible. Mount on a flat surface in an area that will remain dry and is protected from abuse.

Wiring: The battery cable should be sized in accordance with the engine manufacturer's recommendations. Other guides to wire sizes and terminals may be obtained from the American Boat and Yacht Council, Electrical Standards. The brass terminal studs for model 2100 and 2101 are 3/8" diameter; model 2300A are 1/2" diameter, and models 3100. 3101. 3200. 3201 are 5/16" diameter. Be sure all connections are securely tightened. Align the terminals such that they do not cause undue twisting at the switch studs. See tag on stud for correct terminal installation. Alter connecting and mounting of switch, fasten the cables in position with a suitable cable clamp not more than 6" from the switch. Clamp the remainder of the cable not more than 18" apart.

Note:  If the switch is mounted in such a way that the terminals are exposed, then the terminals should be taped or covered in order to comply with Federal Ignition Protection Codes.

Operation: Always reserve one battery for engine starting. Use the second battery for lights, appliances, and other ship's service. "Both" position parallels batteries for emergency use.

Charging: Switch setting indicates battery (s) being charged when engine is running.

Suggested Wiring Diagram for Alternator Field Disconnect Circuit

Alternators with external regulator:

Remove regulator field wire (regulator "F" terminal) and connect to new wire leading to Guest battery switch field terminal (either terminal).

Add another wire from other switch field terminal and connect to regulator "F" terminal.

Use #14 AWG wire for new circuit.

Carefully tape connections for proper insulation.


If it is easier to reach the alternator, remove alternator field wire (alternator "F" terminal and connect to new wire leading to Guest battery switch field terminal (either terminal).

Add another wire from other switch terminal and install to alternator "F" terminal.

Use #14 AWG wire for new circuit.
Carefully tape connections for proper insulation.

Alternators with internal regulator:

The field circuit wire on alternators with internal regulators is located within the alternator housing and it is impractical to use the field disconnect feature. Protection of the alternator diodes can be achieved by installing a Guest isolator #12401 (for 70 ampere alternators) or other appropriate model.

The function of #2100. #2300A. #3100. #3200 selector switches will not be affected if the field circuit disconnect feature is not used.

with battery selector switches, battery isolators, and battery chargers.

Switches   #2101. #2300A. #3101. #3201
Isolators  #2401, #2402, #2403, #2404
Chargers   #2515. #2530. #2540

Guest Battery Charger Systems keep your boat operating at full battery power, at the dock or underway. Chargers are fully automatic and will not overcharge batteries. Chargers also isolate AC shore power from boat's electrical system, provide extra boost for engine starting, function as converters.

Guest switches, isolators, and battery chargers (and your alternator) form a comprehensive power selection and power maintenance system.

For specific information on mounting, wiring, and ratings, refer to Section I for switches. Refer to instruction pamphlets #I-22115. #1-22143, #1-22145 for charger installation and #1-21713 for isolator installation.

Diagram #1   1-alternator,  2 -batteries, 1-switch
Diagram #2   2-alternators, 2-batteries, 2-switches
Diagram #3    wiring changes at regulator and alternator
Diagram #4   1-alternator, 3-batteries, 2-switches
Diagram #6   1-alternator, 2-batteries, 1-Isolator, 1-switch
Diagram #7   1-alternator, 3-batteries, 1-Isolator, 2-switches

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