June 16th, 2010
This aims dispell the myths and misunderstanding surrounding automotive cable sizes, and provide some useful guide to appropriate cable sizing.
Automotive cable is commonly sized by total conductor diameter, and not cross section area like household wiring. As an example 3mm automotive contains 16 x 0.3mm conductors or approximately 1.13mm².
| Cable size |
Maximum Load |
Example Usage |
| 2.5mm |
5 Amps |
Small lamps/LED lights |
| 3mm |
10 Amps |
Light Loads, Headlights, Stereo/UHF |
| 4mm |
15 Amps |
Driving lights, Compressor type fridges |
| 5mm |
25 Amps |
Power feed for other circuits |
| 6mm |
50 Amps |
Power feed for other circuits |
| 8BS |
75 Amps |
Alternator supply, small electric outboard |
| 6BS |
100 Amps |
Power for 50A Anderson plug to caravan |
| 3BS |
200 Amps |
Starter cable, winch cable |
| 2BS |
300 Amps |
HD Starter cable, winch cable |
NB: Cable should be upsized every 3 metres
Posted in Auto Electrical | No Comments »
June 16th, 2010
The automotive car air conditioning system can be a complex system, however the basic principal of air conditioning remains the same.
A compressor driven by the engine draws low pressure gas from the evaporator and pumps high pressure gas to the condensor which is usually located in front of the radiator.
Here the gas is cooled and condenses to a high pressure liquid by the air passing over the fins, this is where the heat taken from the cabin is released.
The liquid is then passed to a filter and reciever that ensures a steady flow of liquid to the TX valve.
The TX valve maintains a constant pressure drop so that the liquid can change state to a gas in the evaporator, this is the unit in the dashboard.
As the liquid changes state from liquid to gas it takes heat from its surroundings and the result is cool air (air without heat) from the vents.
Air conditioners also de-humidify the air making them ideal for demisting foggy windows.
Posted in Air Conditioning | No Comments »
June 16th, 2010
There are a lot of experts when it comes to dual battery setups, and each is entitled to their opinion.
This is the preffered way Coffs Harbour Auto Electrical do it (of course if you have a specific requirement we shall attempt to accomodate you).
The best setup to charge an auxillary battery in an automobile is with a DC-DC battery charger 9like the Redarc BC1220, this can be mounted near the battery being charged and is resilient to voltage drop.
An alternative method that also works well is with the batteries connected using, 6BS cable and a Redarc Smart start solenoid.
If jump starting from the auxillary battery is required we upgrade the cables to 3BS and fit a manual override switch.
Optionally a dash mounted LED can show the state of the Smart start solenoid on the current version.
Posted in Auto Electrical | 1 Comment »