IT WAS OVER IN A FLASH

Most people understand very little about electricity and we've heard of every possible disaster: from blowing the fuse to melting a day's work to paying £400 for an un-necessary extra circuit.

In case you avoided a technical education, there are three commonly-used electrical measurements: Volts, for example 230V, is the pushing power. Amps, for example 5A, is the amount being pushed. Watts, for example 60W, is the energy.

They're related by a simple formula: Watts = Volts x Amps, usually written W = VI. So, a 230V 13A plug can deliver 230 x 13 watts, nearly 3000W. 3000W is usually written as 3.0kW, where a kilowatt is a thousand watts.

As an example, the Paragon SC-2 1745W kiln uses less power than a 2kW convector heater. So, you can plug it into a regular socket. It costs about 14p/hour to run, whilst heating up at the fastest rate, but less normally as the relay cuts in and out.

It's interesting that a 10W radio will fill the room, a 100W light bulb will light the room, and a 1000W heater will warm the room. So, as we pay for electricity by the kilowatt, it's heating devices that cost the most to run. Which is why you get a big bill if you leave the immersion heater on.
Sadly, riding an excercise bike can only generate about 60W of light so, although the exercise keeps you warm, it's hard to be energy-independent. Especially as most of the light bulb's energy is heat rather than light.

Most domestic and small-business buildings have a main fusebox, or consumer unit. Different fuses restrict the amount of current that can be drawn by function groups, such as the lights on one floor, the power sockets on one floor, the kitchen sockets, ovens and grills, a shower and pump, or a garage and outside lights. If you exceed a fuse's rating, it pops.

To supply lights, the fusebox uses several ring mains, each ring separately fused and rated at 5A or about 1200W. Typically, a ring main starts at the fusebox, visits several wall switches and lights in different rooms on the same floor, and returns to the fusebox. The whole circuit is earthed at the fusebox. A lighting circuit is not designed to power heating devices.

To supply power sockets, the fusebox uses several ring mains, each ring separately fused and rated at 30A or about 7000W. Typically, a ring main starts at the fusebox, visits several double sockets in different rooms on the same floor, and returns to the fusebox. The whole circuit is earthed at the fusebox. A double socket accepts two 13A plugs.

To generalise, you can't plug lots of heating devices into all the sockets: neither the fuse nor the cable will survive, although the fuse should pop before the cable burns out. Although fuses are easy to reset or cheap to replace, replacing burnt-out wiring is difficult and expensive.

In older properties, several owners with varying levels of skill, may have changed the circuit or extended it. It's quite common for a ring main, to have a spur to another socket or even to another room. So, take care.

SOCKETS TO SPARE

An extension lead lets you extend the wall socket to a more useful place. Usually, it has a 13A cable and one to six sockets. It's OK for a phone, light, computer, tumbler, drill, and other lower power devices, but not for a collection of kilns and heaters.

Adapters, which convert one socket to two or three, aren't suitable for kilns or heaters. They often seem to get hot and discolour.

A coiled extension can get dangerously hot when running any sort of kiln or heater, so always completely unroll it even if it's on a special drum.

Whichever length you buy, you'll wish you'd bought a longer one, with more sockets. We generally use 3.0 metre six-socket extensions with individual socket switches and indicator lights.

The on-line shop doesn't sell extension leads. The prices vary for no apparent reason: I've seen exactly the same lead for £2.99 and £13.99. You should be able to buy one locally. However, if you can't get to the shops, mail or call.

RESIDUAL CURRENT DEVICE

Typically, we run a tumbler, drill, and work light, from an extension lead plugged into an electronic RCD adapter. However, don't plug two kilns, or a kiln and any sort of heater, into the same extension. Don't touch anything electrical with wet hands.

Although most kilns have a built-in safety cut-out, all equipment in a work environment should plug into an electronic RCD adapter. These detect most dangerous electrical faults because current leaks to earth and triggers the cut-out almost immediately. They're available from DIY stores.

The on-line shop doesn't sell RCDs. The prices vary so much for no apparent reason: I've seen exactly the same product for £6.99 at B+Q and £11.99 in a high street electrical shop. You should be able to buy one locally. However, if you can't get to the shops, mail or call.

Kilns, such as the SC-2, have an outer steel case slotted for air circulation, and the layer of air between the outer and inner steel cases keeps the outside cool. The electrical components and the safety cut-out, located in the base, stay cool, even at extended hold times. So it can stand on a table or kitchen top.
However, things you take out will be very hot and you need somewhere to rest them while they cool. And remember that fired pieces will be hot for some time.

The SC-2 ceramic fibre liner is heat resistant. However, it's not as hard as firebrick so take care using tools to place or remove shelves or pieces.

Although the SC-2 door catch can be adjusted, don't tighten it too much as your pieces may fall over inside as you pull against it to open the door.

Always close the lid or door when you've finished using the kiln to prevent dust accumulating. Don't get into the habit of using the top, or a top-opening lid, as a workspace, storage area, or coffee table.

EYE CARE

When looking into a hot kiln, you must protect your eyes, especially as some materials can flare up or explode. One minor incident could ruin your sight.

The glare-resistant safety glasses in the on-line shop are made from tinted impact-resistant plastic, fit over normal glasses, and can be cleaned with warm soapy water.

HAND CARE

Just because something isn't glowing, it doesn't mean you can pick it up. Use the gloves when loading materials or shelves. Heat blisters are painful and take a long time to heal.

The heat-resistant safety gloves in the on-line shop are made from a special fibre, fit most hands, and can be cleaned with warm soapy water.

PLAN AHEAD

If you're using a kiln, there's always a slight risk that you'll have an accident with hot metal or set fire to something. It's important to have a fire extinguisher, nearby. Read the instructions as soon as you unpack it, learn how to treat burns, buy a basic first aid kit, and fit a smoke alarm.

As soon as the fire is put out, ventilate the room, and make sure that you haven't got the chemical on your skin or in your eyes. If you do, wash with lots of water. If you have any consequential effects, get medical attention.

The fire extinguisher in the on-line shop is rated for electrical fires. It contains sodium bicarbonate, a dry chemical that is non-toxic, helps prevent re-ignition, and doesn't soak soft furnishings.