Posted by Zoe Geoffrion , on Oct, 2015
If your business depends on marine cables and conductors, these are special requirements. First, you must take environmental conditions into consideration. Also, ampacity is a vital issue, whether you are using (0000) 4/0 marine battery cable or deciding which size primary wiring you need for a particular application. Here’s the important information on cable sizing that will keep you or your workers from making critical mistakes in production or repair procedures.
When you install marine cables you need to take four things into consideration:
The right tools
The correct terminals
Proper over current protection
It’s important to understand the ampacity rating of the cables before installation. For example, 4/0 marine battery cable is designed for 12 volt circuits you must not confuse ampacity ratings or information with 120 volt or larger electrical systems.
There are two main factors to consider for cable size selection. The rating of the appliance or battery and the length of cable required. Why is the length so important? As cable length increases, so does resistance, and this affects ampacity. It goes back to Ohm’s Law. In other words, you need a larger conductor for longer lengths of wire, due to the voltage drop.
What about Ground Cables?
Suppose you are sizing 4/0 marine battery cable. You may be concerned with the positive or hot cable but the ground conductor (negative) is just as important. Make sure your ground cable is the same size as the hot one and choose different colors.
Full Load and Startup Current
In most cases, you will want to err on the side of caution when you install marine cables. For example, most loads require a sudden surge of current when starting up, and in some cases this is six times the standard current rating (full load current). This lasts for only a short amount of time, but must be taken into consideration and is the main reason for over sizing conductors. It’s also an important consideration for 12 volts applications like 4/0 marine battery cable. The longer a motor turns over, the hotter the marine battery cables will become.
Tools and Terminals
The right tools and terminal connections are essential to a successful installation. Use quality cutters and crimpers for best results. Plus, you must make sure the terminals are rated to handle the circuit and wiring ampacity.
Over Current Protection
Choosing the right circuit breakers and fuses are important. Never opt for less protection than needed. In other words, if you are not sure to install a 35 or 30 amp breaker, go with a 30. You can switch to a 35 if you receive a lot of tripping during testing.