Part 27

Every home should have at least two small-appliance circuits.

3. Individual or special-purpose circuits--One of these is needed for each: electric range, dishwasher, water heater, freezer, automatic washer, clothes dryer, air conditioner, pump, and house heating equipment.

+----------+------+------+------+------+-------+ | | | | | | | | Actual | | | | | | | Size | | | | | | +----------+------+------+------+------+-------+ | Gauge | | | | | | | Size | 14 | 12 | 10 | 8 | 6 | +----------+------+------+------+------+-------+ | Fuse or | | | | | | | Breaker | 15 | 20 | 30 | 40 | 55 | +----------+------+------+------+------+-------+ |Max. Watts| | | | | | |at 115 V. | 1725 | 2300 | 3450 | 4600 | 6325 | +----------+------+------+------+------+-------+ |Max. Watts| | | | | | |at 230 V. | 3450 | 4600 | 6900 | 9200 | 12750 | +----------+------+------+------+------+-------+

Each Circuit Big Enough

The capacity of each circuit is limited by the size of its wires. The chart above shows you the actual sizes of wires commonly used in permanent home wiring, and what each will carry. Notice that each size is given a number, and the smaller the number, the bigger the wire.

Also notice that a given size of wire will carry twice as many watts at 230 volts as it will at 115 volts. (Watts are figured by multiplying amps times volts.)

General purpose circuits usually are either Number 14 or Number 12 wire, at 115 volts. What is the capacity of each, in watts? (Number 12 wire is recommended for all new general purpose circuits.)

Small appliance circuits are required to be at least Number 12 wire.

Individual circuits are always sized according to the appliance they serve. Find the size wire that should be used for a 10, 000-watt, 230-volt range; a 1500-watt, 115-volt dishwasher; a 4500-watt, 230-volt clothes dryer. _______ ______ _______

Only One Fuse Size Right

A fuse in an electrical circuit is like an alert traffic policeman--stopping everything if there's danger. A circuit breaker serves the same purpose, and the right size is installed when the wiring is done.

A policeman uses his brain to tell him when to blow his whistle, but a fuse depends on the size of the little fusible (meltable) metal link that you see under the glass.

If too great an electrical load is added to a circuit, this link will melt and prevent a dangerous overload. If you put in a fuse with too heavy a link, it will not melt in time, and the wiring and equipment may be damaged.

Therefore the right size of fuse is very important, and is something that you should check in your own home.

See the chart above for the right fuse for each size wire.

Make a Circuit Chart

At one or more places in your home there is a box or panel containing the fuses or breakers for the various circuits. Attached to the inside of the door of each such panel should be a chart something like this:

+-----+---------------------+-----------+ | No. | Description | Fuse size | +-----+---------------------+-----------+ | 1 | Range | 40 | +-----+---------------------+-----------+ | 2 | Kitchen Outlets | 20 | +-----+---------------------+-----------+ | 3 | Dining Room Outlets | 20 | +-----+---------------------+-----------+ | 4 | Living Room Outlets | 15 | +-----+---------------------+-----------+ | | | | +-----+---------------------+-----------+ | | | | +-----+---------------------+-----------+

Notice that in our chart we have made columns for a description of what each circuit serves, its number or position in the panel, and the proper size fuse for it.

Because most such charts leave out this last very important bit of information, you should make a complete new chart, like the one shown. Provide as many lines as there are fuse positions. Paste or tape it to the inside of the panel door.

Then, ask permission of your parents to disconnect all the circuits by unscrewing the fuses or flipping the circuit breakers. Do not touch anything but the fuse rim. Then reconnect them, one at a time, to find out what each circuit serves. Turn on as many lights as you can, to help you in your detective work. Use a test lamp at those outlets that do not have a light connected to them. Write two or three words describing each circuit on the proper line on your chart.

On a separate sheet, keep track of the appliances and lights that are on each circuit, and add up the watts. (If the name-plate of any appliance gives "amperes", "amps", or "A" instead of watts, just remember that amps times volts equals watts.) This will tell you if any of them are overloaded. Show this sheet to your parents.

Check the Wire Sizes

Disconnect the main switch, and determine the size of the wires in each circuit. Don't include the insulation in your measurement.

_BE CAREFUL!

Even though you have disconnected the main switch, the wires coming into it are still "live". So, do not touch any wires. Instead hold the wire size chart near them so that you can tell which gauge each one is._

Write in the proper size fuse for each circuit on your chart.

Replace Any Wrong-Size Fuses