Where and when to use fuses In an ideal world each individual section of positive cable would be fused as this would provide the most protection and make fault finding relatively straight forward, because it would allow you to narrow down the problem to a single section of cable i. Now superseded in modern vehicles by blade fuses but found in some older cars and still used for some classic restorations. If replacing a blown fuse in a manufacturer-designed factory application, e. Fusing Guide Overview Fuses are critical in any electrical system and are used to protect a circuit's cabling from excessive current that could lead to damage and, very often, an electrical fire. In simplified terms the greater the current is above the continuous rating, the faster the fuse will blow. Although these charts are an excellent resource, they are a bit intimidating. This is important because if a section of cable shorts to ground it will only be protected if there is a fuse before the shorting point otherwise the fuse will not experience the excess current because it will be outside of the short-circuit. How much current will it take for a fuse to blow?
Wire thickness needed –
Maximum current - amps - through a 12V circuit - related to size (AWG) and cable with length 15 m is approximately 15 amps according the diagram above.
12 Volt Wiring Gauge Requirements at specific Amps to length for Automotive numbers, Amps and length, locate the nearest gauge value in the chart below. HOW TO Guide. Install Your 12v Compressor. Fridge.
Fusing Guide 12 Volt Planet
Tools Required: For most fridge installations in a small campervan a cable size of mm, 44 strand.
Manufacturers show this blow time on a Current-Time chart but for the typical user it's not necessary to go into this level of technical detail as long as you follow some basic fuse selection guidelines as described in the next section: Selecting the correct fuse rating If replacing a blown fuse in a manufacturer-designed factory application, e.
Excessive current is most likely to be caused by three things: Incorrect wiring - wrong connections as a result of human error Damage to the circuit - e. In an ideal world each individual section of positive cable would be fused as this would provide the most protection and make fault finding relatively straight forward, because it would allow you to narrow down the problem to a single section of cable i.
These fuses are bolted down into fuse holders or boxes. All Rights Reserved.
Part 1 Choosing the Correct Wire Size for a DC Circuit Blue Sea Systems
Generally now used in lower current applications such as audio head units and accessories cigar lighter socket plugs etc.
wiring a campervan electric system Below is a chart for picking your minimum wire size. To use the chart. Wire Gage Calculator, Wire Size Calculator, Wire Sizing Calculator, Wire Size Chart, GXL Wire Calculator, TXL Wire Calculator, MTW Wire Calculator. exposed to open air for cooling) and not power transmission wiring (a large wire harness.
Video: Wire gauge guide 12v cooler Tutorial for Calculating Wire Sizes for DC Applications.
Since this chart is in Amperage and not wattage, the same values should apply to 5v and 12v too, only the percentage drop will change but you.
However, you also do not want the fuse to keep blowing under normal operation known as a nuisance blowso the two elements to consider are:.
Increasing in popularity is the micro blade version also known as APS or ATT fuses with more widespread use expected in the future as manufacturers attempt to fit more electrical systems into the same space Maxi blade fuses also known as APX fuses tend to be used for higher current or 'power' applications and are available in higher ratings.
Doing this creates a high risk of component failure and electrical fire.
Video: Wire gauge guide 12v cooler What Size Wire Do I Use To Wire My Solar Components? Does Wire Size Matter?
Found this article helpful? Starter motors are normally the highest current draw electrical item on a vehicle as they have to crank the engine, and the current can reach several hundred Amps, especially with large diesel engines that have a high compression ratio. The Circuit Wizard, at circuitwizard.