Is it safe to use electricity in the garden?

When you’re considering electrical safety in the home, there are two areas that require a higher level of protection than the rest of the property. One of these areas is the bathroom or wet room. The other is the garden and outbuildings.

The common factor, here, is water. Water is an essential part of our daily lives – whether we’re taking a daily shower, or whether our gardens are being drenched by rain. As we all know, water is a dangerously good conductor of electricity.

However, water isn’t the only hazard when it comes to using electricity outdoors. Cables lying on the ground can be severed or corroded. And there’s always a risk of buried electrical cables being damaged by excavation or by intrusive tools.

Although the garden can indeed be a very dangerous place for electrical installations and appliances, it can be as safe as your wet room – if you do it right.

How deep should electrical cables be buried?

It’s generally accepted that electrical cables – protected by steel armour or enclosed in PVC conduit – should be buried at least 60cm (2ft) deep.

Although there’s no legislation stipulating the depth of buried cables, UK building regulations require all outdoor cables to be deep enough that they won’t be damaged by any reasonable disturbance of the ground. Therefore, cables running beneath a patio wouldn’t need to be as deeply buried as cables under a lawn. Cables running under a vegetable plot, however, need to be a lot further beneath the surface than those under a lawn.

IP code

International Protection marking (IP code) is a rating system published by the International Electrotechnical Commission (ETC). One of the code’s functions is to classify the degree of protection provided by electrical enclosures. In the UK, the IP code is generally known as the Ingress Protection code.

The first digit (graded 0 to 6) represents the item’s resistance to solid matter. The second digit (0 to 8) represents its resistance to water. An X signifies that there is insufficient data for a level of protection to be assigned.

This is a brief summary of the IP code:

Solid particle protection (1st digit)

RATING PROTECTION LEVEL
X No rating: insufficient data
0 No protection
1 >50.0 mm
2 >12.5 mm
3 >2.5 mm
4 >1.0 mm
5 Dust protected
6 Dust tight

 

Liquid ingress protection (2nd digit)

RATING PROTECTION LEVEL
X No rating: insufficient data
0 No protection
1 Dripping water
2 Dripping water (enclosure tilted at 15°)
3 Spraying water
4 Splashing water
5 Water jets
6 Powerful water jets
7 Immersion (up to 1 metre)
8 Immersion (1 metre or more)

 

So, for example, a rating of IP41 means:

  1. The enclosure will be inaccessible to fingers etc, although dust and some insects will be able to get in.
  2. The enclosure will be resistant to a few drops of water, but it won’t keep out heavy rain.

Residual current device (RCD)

If you’re using plug-in electrical appliances in the garden (for example, a lawn mower or hedge trimmer), or if you have electricity installed for permanent fixtures (like a hot tub, pond pump, shed lights, or greenhouse heater), it’s essential that the electricity supply is protected by at least one RCD.

A residual current device (RCD) is a potentially life-saving piece of equipment that will cut off the electricity supply if there’s inconsistency in the current. There should be an RCD in your consumer unit. However, even if you’re plugging outdoor appliances into an indoor socket, we advise additional protection by installing a dedicated RCD for that socket.

Enjoy your garden!

To talk to us about safe electrical installation in your garden, give us a call on 01603 559 311.