Inc. One Selector Battery Switch Installation Manual

Wire Sizing Chart

1. Calculate the maximum sustained amperage of the circuit. Measure the

length of the circuit from the power source to the load and back.

2. Calculate Famps (Feet x amps). Multiplycircuit lenght by max. current.

3. Base the wire on either the 3% or 10% voltage drop. In general, items

which affect the safe operation of the boat and its passengers (running

lights, bilge blowers, electronics) use 3%; all other loads use 10%.

4. Are the circuit runs in an engine space or non engine space?

5. Starting in the Famps column with the right voltage and voltage drop,

run down the list until arriving at a value which is greater than the

calculated Famps. Move left to the Ampacity column to verify that the

total amperage of the circuit does not exceed the maximum allowable

amperage of the wire size for that row. If it does, move down until the

wire ampacity exceeds the circuit amperage. Finally, move left to the

wire size column to select the wire size.

Note: For wire with 105°C insulation rating and AWG wire sizes.

Chart courtesy of the West Advisor

COMMON

LEDLEDLEDLED

TO 24 HOUR

CIRCUITS

TO DC HOUSE

DISTRIBUTION

PANEL OR HIGH

AMP DC LOAD

100A

OUTPUT TO

ENGINE

ALTERNATOR

OR STARTER

DC NEGATIVE

DISTRIBUTION BUS

CL-SERIES 7600

BATTERYLINK

ACR

B A

HOUSE

ENGINE

Wiring Diagram

Dual Battery Main Distribution Panel

PN 8687 Shown

Example

A 12 volt system at 10% drop with a 40’ circuit x 45 amps = 1800 Famps.

A wire size of 8 is required.