Double Insulated Lights V Normal Lights. Looking inside & comparing

Normal Lights Vs Double Insulated Lights

From the outside a double insulated light looks exactly the same as a normally earthed light. You cannot tell the difference in any way from just looking at a product. Once you delve inside the products however it becomes quite clear what the differences are. The first thing to realise is that every light fitting, be it normal or double insulated, should always have a silver sticker somewhere inside that tells you information such as maximum wattage to be used, if the product can be fitted on flammable surfaces and what the products class is.  A class 1 product requires an earth connection and should display a symbol that looks like an arrow head.

The arrowhead symbol (yellow sticker) indicates an earth connection is required

A class 2 product is double insulated, which means it doesn’t require an earth connection. These types of products display a symbol which is a square within a square.

The square within a square symbol tells us that this light is double insulated and doesn't require an earth connection

The reason a light fitting is double insulated is because it is designed to be fitted where an earth connection isn’t present in a buildings electrical lighting circuit. If we imagine for a moment a normal light that is earthed has an issue such as a wire becomes loose and touches the body of the light then the resultant danger is saved by virtue of the earth wire taking away the fault and almost certainly tripping out the fuse on your circuit board, rendering the fitting safe.  If there was no earth wire present and the same issue occurred then the light would become live and a very dangerous situation would occur that could lead to electrocution and possibly death.

This is where a double insulated light comes in. Looking inside a class 2 double insulated light at the wiring highlights the differences against a normal light. The first thing to note is that a heavy duty sheath (black) is present to insert the connecting wires in to. Once through this sheath the wires (live and neutral plus any other accompanying wires) are fitted in to a plastic box that fully closes after the connections are made. The wiring from the light itself in to the same box is also protected by additional insulation. If a fault occurred, such as a loose wire on this light, then there’s no way for the loose wire to touch the body or any other part of the light. The unit does not become live and your fuseboard (consumer unit) would detect a fault, cutting the power to the light.

In a double insulated light the incoming wiring is fitted within sheaths and protection boxes as well as extra insulation to ensure a loose wire never touches the light

This is why a double insulated light can be made or metal or similar conducting materials because the wiring is designed and fitted in a way to ever stop them touching the actual product and creating a dangerous situation.

In this double insulated light the connections are made within a poly-carbonate housing that separates the wiring away from the actual product

It is worth noting that double insulated lights are wired professionally by manufacturers and are tested thoroughly before given the go ahead to be released as a double insulated light so please don’t attempt to rewire a class 1 light in an attempt to make it class 2.

For a full range of double insulated lights and further advice you can visit our website. We have specialised in class 2 lighting for over 20 years.