How to wire up an inverter

First some important safety information!

Inverters produce 240V AC, just like household sockets, which is more than enough to kill you. It is vital to install them with care and treat them with respect. The inverters we sell are designed to power one appliance connected directly to the outlet socket only.

If you wish to connect your inverter to any kind of 240V distribution system, it must be properly designed and constructed, earthed, protected by an RCD (residual current device - cuts off the power in the event of a fault) and preferably installed by a qualified electrician. Please note that it is illegal to do your own 240V wiring in any permanent building in the UK.

First, choose where to install your inverter. It should be as close to your batteries as possible, and in a dry, well ventilated area. And unless you install a relay (see below) you will need easy access to the on switch!

Most inverters have mounting holes allowing you to screw them directly to a wall or surface. When choosing a spot, ensure you can still access the DC terminals, socket, switch and fuses.

Using the cables supplied, connect the inverter to the battery. It is fine to shorten the cables, but if they are too short you should replace them with a cable that is thicker as well as longer.

If your inverter has an earthing point, connect this to a suitable earth with heavy gauge wire, preferably 2.5 square mm. On a steel-hulled boat, a suitable earth is any substantial bolt or stud on the hull/engine that is close to but not touching the point where the DC negative meets the hull/engine. On land, you should use a proper earth stake driven into the ground, available from any electrical supply store.

Earthing is important as if the inverter is not earthed then neither are your appliances, and a fault in the appliance could make the whole thing live.

Plug an appliance into the inverter's AC outlet, respecting the inverter's maximum power rating, and switch on the inverter. The power light should come on and you may hear a fan running. Finally, switch on your appliance and hey presto, 240V electricity!

Some inverters, like our Steca sine inverters have an automatic standby mode but others will need to be turned off when not in use to avoid wasting electricity.

You may find it inconvenient to get to the inverter to switch it on and off all the time. A solution is to fit a relay in the positive (red) DC cable. This will allow you fit a small remote switch in a convenient place some distance away from the inverter itself. Any small switch can be used, a domestic light switch would be fine.

When buying your relay, ensure the relay can handle the large current that your inverter may draw; a 1000W inverter may draw 80 amps so a substantial relay is required. Our Durite 100A split charge relay is ideal.

Mount the relay in a convenient spot near the inverter. Detach the positive (red) DC cable from the battery and cut it near the relay. Connect the two cut ends to the two large terminals on the relay, usually labelled '87' and '30'.

Now connect a thin black cable between the small relay terminal marked '85' and any convenient negative connection (eg. the inverter's negative terminal).

Finally, use thin red wires to connect your remote switch between the battery positive terminal and the small relay terminal labelled '86'.

Reconnect the battery, and turn on the inverter. If all goes well, you will now be able to control the inverter with the remote switch.

buy

solar panels
Framed panels
Framed polycrystalline silicon solar panels. Great for a wide variety of uses.
Framed panels - large
Larger framed silicon solar panels - for more power hungry installations.
Semi-flexible panels
3 ranges of low-profile, marine-grade panels designed with the yachtsman in mind. Great range of sizes from 5W to 70W.
Flexible panels
Ideal on boats, or expeditions!
Peel 'n' stick panels
Flexible thin-film solar panels with an adhesive backing.
Solar panel kits
A range of framed, laminate and semi-flexible solar panel kits complete with solar regulator, cables and connectors.
Grid-connect PV

On the grid

With payments from the feed-in tariff, installing solar panels on a roof makes sense financially as well as economically. Our local installation team would be delighted to quote for an installation. Please see our dedicated website for solar panels in Cambridge: midsummersolar.co.uk

We work with other solar panel installers outside of Cambridge too. If you would like competitive quotes for a solar PV installation outside of East Anglia, please visit solar-pv-quote.co.uk

regulators
Solar Regulators
The world leaders in PWM solar regulators.
MPPT Solar Regulators
Get more power from your panels.
wind turbines
Leading Edge
Bombproof and British.
Rutland Turbines
Small, economical wind turbines, ideal for battery charging on yachts.
Forgen Turbines
Reliable vertical axis turbines - great for remote power solutions.
lights
Fluorescent lights
Efficient fluorescent lighting from Labcraft for boats and caravans.
LED lights
Stylish efficient lighting with new LED technology.
inverters
Modified sine inverters
A range of 12V-240V inverters providing great value for money.
Sine wave inverters
Sophisticated sine wave inverters for improved versatility and reliability.
Inverter chargers
Combined chargers and sine-wave inverters.
batteries
Powermax
Great value maintenance-free leisure batteries - ideal for boats and caravans
Haze Gel batteries
High-spec zero- maintenance gel batteries at great prices
Rolls Solar
A full range of these robust top-end solar batteries is now available
Crown Renewable
Diverse range of high quality solar batteries
Mastervolt chargers
Very high-spec chargers suitable for marine use
Chargers and accessories
Battery terminals, chargers, split charging devices and more.
odds & ends
Meters & Monitors
Keep an eye on your battery bank's state of charge with these meters and battery monitors.
Cable & Connectors
All the connectors you need, and high-grade cable to finish off your system
Solar Panel Mounts
Versatile mounting solutions to secure solar panels to poles and roofs
Clearance!
Keep an eye on this page for the latest bargains.
systems
Off-grid power
Complete power systems for properties with no grid connection
Bespoke Solutions
We design and build remote power systems to fit your needs and budget
trade
Trade customers
We offer great discounts for trade customers placing multiple orders. Please contact us for more information