Beware the Cheap Camping Hook Up Lead
Browsing through well-known auction and sales websites you can come across a large number of sellers offering cheap caravan and camping electric hookup leads, and at first glance they can seem like a real bargain.
But many of these leads are little more than a standard household 4-way socket, wired to a blue campsite hookup plug. This design is based on a 4-way adapter designed for indoor use - NOT for prolonged outdoor use in a caravan awning or a tent.
It would seem that many of these cheap camping mains sockets are made by some sellers at home, and not produced to commercial standard, and not properly tested or approved as a commercial product. That may not seem such a problem on the face of it - after all "any fool can wire a plug". But what guarantee do you have that it is not indeed "any fool" that has wired your new hookup lead badly?
That "homebrew" camping EHU that looks like such a great deal could be hiding any number of potential problems
1) Bad Wiring or low-quality connections
If a hookup has been constructed on a "kitchen table assembly line" has the necessary care been taken assembling the plugs and sockets. A professionally constructed unit will have safe and sound connections - there may be no guarantee of sound wiring with many of the budget unbranded units sold by internet marketplace sellers. Bad wiring can lead to short circuits - loose wires can cause fires. Many professional electricians will testify to seeing poorly fitted plugs and connections done by the DIY'er who may have been oblivious to the danger.
2) Incorrect Cable Used
A genuine campsite electric hook up will come with highly visible orange cable. The colour of the cable is important as it is contrasts with both grass pitches and gravel, is clearly visible even in some longer grass, and can be seen by people walking, as a trip hazard, or by campsite caretakers who may be trimming grass. Dark blues or black leads are hard to see, and lighter white or grey mains leads are not as visible as the standard orange outer.
The rating of the cable is important too - a 2.5mm core mains lead is required on most UK caravan sites to satisfy IEE regulations ; rated to either 20 or 25 Amps (depending on the insulation and grade of copper).
1.5mm lower rated cables are available too as this seems to be the preferred standard in Europe where site connections may have a power output lower than the UK 16 Amp standard . These leads may be fine at many sites which are fused at much lower than the 15 amp capacity of the 1.5mm cable, (many sites provide a 10 Amp supply or some even as low as 5 Amps) and these cables are popular for such use due to the lighter weight of the cable, especially as a hookup for motorcycle camping. Whilst Towsure supply such extension leads for this type of use, a camping mains unit for UK use should always use the 2.5mm grade of cable. Some supposed "camping hookup leads" sold via internet marketplaces do not reference the grade of cable used
3) Damp Protection
Household 4-way adaptor sockets are, as the name suggests, intended for household use indoors. They are not normally designed to be weatherproof.
Water and Electricity are a dangerous combination - we are all familiar with the early morning dew even on fine days. Household sockets are not designed for this level of moisture, let alone moisture from the rain which we are all used to as British campers and caravanners!
Cheap home-made hookups can be very dangerous if they get damp!
4) No Circuit Breaker Protection
Many discount camping mains leads come with just a blue mains plug and a socket; with no protection in place. Some take the view that "the campsite has a circuit breaker so why worry?"; however the recommendation from many campsites and from the Camping and Caravanning Club is to also have your own RCD (Residual Current Device) on your own mains unit to cut off the supply in the event of a fault 
What Should I Look for in a Caravan and Camping Mains Unit?
A typical Electric Hookup Unit (EHU) for UK use will have either one or multiple 13 amp socket outputs with an integral power distribution box with a transparent window. It will have a 10 Amp double-pole Miniature Circuit Breaker (MCB) and a 25 Amp RCD.
These sockets and distribution box should be housed in a weatherproof housing, protected to a minimum of IP44, which means it is protected against both dust and wire ingress and water splashes 
Blue 3-Pin plug (sometimes these are blue & white/grey) approved to BS EN 60309-2, connected to the mains unit with a maximum of 25 metres 20-25A rated orange cable 2.5mm core
Why do I need a circuit breaker when the caravan site post already has one?
The simple answer is "Belt & Braces" - which is a sensible thing when dealing with outdoor units. Having a double level of protection is safer than one. However there are other reasons:
Doubled-Up Hookups - Some campsites double up on each hookup post - meaning that if a fault with your electrics or if you inadvertently overload the supply, tripping out the site's circuit breaker will cut your neighbour's power. If a fault causes this to happen multiple times you may not be the most popular member of the campsite!
Charges for Resetting the Supply - Some (not all) sites may require a site warden or caretaker to reset the power supply, meaning out of hours this will leave you without power - and it can sometimes incur a charge. Having your own circuit breaker reduces the risk of this, allowing you to reset your own power after removing the faulty or overloading appliance.
Using your Camping Hookup Safely - Tips
Once you have a suitable camping & caravanning mains unit, there are a few safety tips still to follow, to keep you and your family safe.
Always use the lead fully extended
The standard length of a hookup cable or extension cable is 25 metres which should be enough to reach the electricity point from your pitch. If your pitch is closer, do not coil the excess cable, as a coiled cable acts as a heating element. Lay the extension lead out so that it is not coiled, where it is not likely to cause a trip hazard.
Keep the Mains Unit Dry and Raise it off the Floor
Whilst a properly rated mains unit is resistant to damp and splashes, it should be kept off the floor in case of spillages or heavy rainfall. Many units come with clips to attach to awning poles, a hanging hook or a stand. For some units a mains unit stand is available as an optional extra.
Do Not Leave Cables on an Empty Pitch
If you are camping in a motorhome and driving off-site, store your cables away to prevent plugs and leads being accidentally damaged, or water entering the plug or socket.
Know the Rating of your Campsite's Supply and Keep To It
The amount of appliances you can use depends on the rating of your site supply. Power consumption of appliances is measured in watts, but the hookup rating is measured in current (Amps) - so how do you know what you can plug in?
There is a simple calculation; Power in Watts = Voltage x Amps
- For a 16 Amp supplythis means that you have a maximum of 230 volts x 16 amps = 3680 Watts
- For a 10 Amp supplythis drops to 230 volts x 10 amps = 2300 Watts
- For a 5 Amp supplythis is as low as 230 volts x 5 amps = 1150 Watts
To decide what you can plug in, check the power in Watts on your appliances and add up the total of the items you wish to plug in at the same time, and ensure the total wattage is below the maximum available. Exceeding the wattage means that you will trip the circuit breakers out.
Using low-wattage camping appliances helps keep within the limits, for example a household kettle may be as high as 2.5kW (2500 Watts) meaning it is unusable on anything but a 16 Amp supply. A low-wattage kettle of 800 Watts or lower is suitable for all supplies (when not used with other appliances that would take the power over the limit)
Immediately Stop Using any Damaged Equipment
In the event of any electrical appliance developing a fault, or damage to any plug, cable or mains unit - STOP USING IT IMMEDIATELY AND DISCONNECT IT FROM THE SUPPLY WHERE SAFE TO DO SO. If it is not save to disconnect (for instance if a connected plug is damaged) inform the site office immediately
Using the correct equipment and following these basic safety guidelines means that you can enjoy a worry free holiday with all the electrical home comforts you require!
 IEE Regulations Section 7 -http://electrical.theiet.org/books/guidance-notes/gn7-5ed.cfm
 Camping and Caravanning Club Datasheet: Electricity for Campers and Caravanners - http://www.campingandcaravanningclub.co.uk/helpandadvice/technicalhelp/datasheets/electricity-campers-caravanners/
 IP Ingress Protection Ratings - https://en.wikipedia.org/wiki/IP_Code