Inverters. 12/24 Volt DC to 230 Volt AC
When you need 230 Volt on your boat, in the caravan, Cabin or in any Off Grid installation, you must have converted your 12/24 Volt DC voltage to 230 Volt AC.
There are several things to consider and include in your calculation.
On the 230 Volt AC side:
- First, you need to control how many watt you need to pull from the inverter at the same time. You should therefore know the maximum watt age from the fridge, the radio, the fans, etc. if these potentially could run at the same time. You must put all these wattage numbers together and you then have the watt number that you should be able to extract from your inverter as an absolute minimum.
- When you know how many watt you needs continuously, you may also have to look at the start power usage. It’s usually not a problem if you buy a quality inverter, such as the ones from MasterVolt, as they are able to deliver up to the double watts in short moments and it usually covers the need, but it does depends on your equipment.
- You can pull all the power from your battery bank via your inverter, but you need to make sure that there is enough power on the battery to deliver the amount of power needed, and not least at the rate you are going to consume it.
Because it does not help to have a battery that contains all the power you need to use, if the power is needed suddenly and in large quantities. Your battery may not be able to deliver at the current you need. AGM and Lithium batteries are fast, while GEL can be a bit slow, but read our battery guide to learn more about the batteries.
Sun, wind and other energyEnergig publishes ongoing guides to help you find solutions to your power challenges. Whether it's an advanced Off Grid facility or a more standard solar cell setup for the villa, you'll be able to find information and instructions here in our guides. They are divided into On Grid (Grid tied) installations and Off Grid installations that will work without the Grid. Often, solar and wind turbines are used, but there are other possibilities.
Power electronicsWhen working with power, there is always a need for controlling it, so the power is right for your purpose, but there is almost always a need to convert to other voltages, have batteries are charged, insulating (possibly galvanic), monitored, alarmed, data retrieval and much more. Fore that we use power electronics. We have therefore also published guides on inverters, shunts, battery chargers, etc. so you get an understanding of what the different parts have of functions. We are also expanding these guides on a regular basis
SecurityIt is not harmless to work with power! Not even though it is DC and thus often fully legal to work with. There are many aspects that need to be taken into consideration and therefore you should always pay close attention to stuff like fuses of the correct size and not least cables of the right thickness. Failure to use or use to small/large fuses and cables may cause malfunction, lack of power and fire. So read our guides for securing and dimensioning your system.
- There are 2 different basic technologies used when converting 12/24 Volt DC to 230 volts AC
- Modified sine wave is the “old” method that delivers an almost square “sinus” curve to the consumers. You should use this technology ONLY if you absolutely know that your consumers can handle this type of “sinus” curve. As a rule, we do not use it today unless there will never be any other equipment connected, than equipment intended from the start. And if you do not know if your equipment can handle this, stay away from Modified Cine Curves.
- True Sine wave is basically a fine rounded sinus that are taken straight from the electrician’s textbook (see further down).
This sine wave curve will work with all 230 Volt AC devices (provided the inverter can deliver enough wattage). From a good True Sine Wave inverter, there is a sine wave that is even better than the one that comes from the power plant.
With this type of inverter you are safe and I usually recommend it as a standard.
- When working with 12/24 Volts DC, you often may do the whole installation yourself, it may although not always be advisable!, but you are allowed do it.
However, do not make permanent 230 volt AC installations. An authorized electrician must do that.
You may connect extension cables to your 230V inverter if there is an ordinary plug on the inverter and then connect it to your consumers. It’s the same principle as if you were connected to the mains home in the villa.
- When choosing your inverter, I would recommend you to be critical of the quality as this is the source of all your 230 Volt consumers. Thus, electrical noise from your inverter will propagate to your consumers and potentially produce noise in your different consumers.
From all inverters there is a ripple voltage that overlays the sinusoidal curve. It should be as low as possible as it may potentially shock and, in extreme cases, destroy your consumer equipment.
The quality of your inverter also results in the shape of the sine wave that comes out of your inverter (true sine wave inverters). A poor quality inverter makes offbeat sinus curves and then begins to resemble the output from a modified sinus inverter.
Typically, when the inverter is under load, the sinus curve becomes strained and especially during peak loads, the sinuses can be very out of shape. This does not happen from a quality inverter.
The quality is of course also a matter of how many years a given inverter will last before it is worn out.
And what does that mean?
If you need to have your inverter in a boat or a vehicle, choose an inverter that is marine approved, as it can withstand the shakes and the salt and moisture in the surrounding climate.
Qualitatively, you get what you pay for (sorry but that’s just how it often are 🙂 ) and do you need to have a solid supply for years without trouble, noise and ruined consumers? don’t save your money here.