13
Nothing comes close to a Cobra
®
Ground Wiring
•
There is a screw on the rear panel for Chassis Ground. This is to connect the chassis
of the inverter to ground.
The Chassis Ground Screw must be connected to a grounding point, which will vary
depending on where the unit is installed. Use a #8 AWG copper wire (preferably with
green/yellow insulation) to connect the chassis ground screw to the grounding point.
In a Vehicle:
Connect the Chassis Ground to the chassis of the vehicle.
In a Boat:
Connect to the Boat Grounding System.
In a Fixed Location:
Connect the Chassis Ground Screw to earth ground by connecting
to a ground rod (a metal rod pounded into the earth) or other proper
service entrance ground.
12 English
Power Consumption
•
For each piece of equipment you will be operating from the inverter, you must
determine the battery’s reserve capacity (how long the battery can deliver a
specific amount of current — in automotive batteries, usually 25 amperes) or
ampere-hour capacity (a measure of how many amperes a battery can deliver
for a specified length of time).
Example – Reserve capacity: a battery with a reserve capacity of 180 minutes
can deliver 25 amperes for 180 minutes before it is completely discharged.
Example – Ampere-hour capacity: a battery with an ampere-hour capacity of
100 ampere-hours can deliver 5 amperes for 20 hours before it is completely
discharged.
To Determine the Battery Ampere-Hour Capacity You Require:
1. Determine how many watts each piece of equipment consumes. This can normally
be found on the product label. If only the current draw is given, multiply the current
draw by 115 to get the watt consumption.
2. Estimate the time (in hours) that each piece of equipment will be running between
battery charging cycles.
3. Calculate the total watt-hours of energy consumption (power x operating time) using
the average power consumption and the total estimated running time (in hours).
Power x Operating Time = Watt-Hours.
4. Divide the watt-hours by ten (10) to determine how many power supply’s (12 volt)
ampere-hours will be consumed.
Installation
Power Consumption
Installation
Ground Wiring
300 Watts x 15 minutes
= 75 Watt-Hours
115 Watts x 3 hours
= 345 Watt-Hours
Blender
TV/VCR (up to 25")
100 Watts x 2 hours
= 200 Watt-Hours
Laptop
Chassis Ground
