File:Electricty Handbook.doc

Actual handbook for Electricty Handbook IPS Group project

Electricity Handbook for your new HFE Home!

Introduction

Welcome to your new home given to you by Homes for Everyone (HFE). We hope you enjoy your new living place. We also hope that in the future you will volunteer your time to building houses for other needy families, just like you. Please keep the generosity flowing.

Your new home has a very special electrical system. Please take a few minutes with this handbook to become familiar with the system.

Your home has a very limited supply of electricity. This is because your home is not on the power grid. Power is supplied by a special wind generator. This means you will never need to pay an electricity bill for as long as you live here. However the generator only has a limited output, which means that you must closely monitor your electricity usage. If you do not closely monitor your appliances, you will not have enough electricity to cook food and have hot water for the rest of the month. To compare with what you paid before, you have only about $9 of electricity a month to use. This is a tiny fraction of what a typical household should have. You will need to conserve energy. You can do this by turning off the lights and fan when you are out of the room, as well as the computer when you are not using it.

Hot Water System

Your new home also has a special water heating system. The hot water produced by the system heats the house in the winter and provides hot water. A large "pond" of water is located on your roof. When water is in there it will be heated without the consumption of electricity. This stretches the amount of electricity available for other uses. A transparent cover over the pond stops the water from evaporating. There is also a traditional backup water heater for cases when the sun is not strong enough.

The system works because a pump circulates the water through the system. Cold water first flows from the municipal water supply to the heating tank on the roof. There, it is warmed by the sun. The water then passes through the backup water heater which is used when the sun can not sufficiently heat the water. Then there is a switch. In the summer, the water goes to a storage tank and in the winter, the water circulates through the house to heat it. The water then is used for bathing and hand washing from the tap.

Electricity 101

This section is designed to give you a short introduction to the topics of electricity. Your new home will require you to have a basic knowledge of electricity and how it works in your home. Because of the off-the-grid nature of your home, you are responsible for keeping your electrical system up and running. There is no utility to call if something goes wrong.

Introduction to Circuits

Electricity travels only through complete circuits. Circuits are the paths which electrons follow. If the circuit breaks, the electricity can no longer go around in a circle and it stops. Electricity does not flow unless there is a circuit.

In a circuit, the electricity comes from a source. In this house, that is the batteries of the wind generator. It then flows through the wires of the house to a load, which is something that consumes electricity. After the electrons pass through loads, they return back to the source.

There are two different ways circuits can be arranged. They are called series circuits and parallel circuits. Parallel circuits are the types used in all homes including this one.

Series Circuit

A series circuit is when there’s a single path for the electrons to flow throughout the circuit. If one appliance in a series circuit is turned off, all the rest of the appliances lose power.

(diagram)

Parallel Circuit

A parallel circuit is when there are multiple paths for the electrons to take. Each load has a separate branch in the circuit. Because of the separate paths for the electrons, if one appliance is turned off the rest of the appliances can stay on. This is an advantage because if an appliance is turned off or breaks, the rest of the circuit does not lose power. However, it requires more wiring to set up.

(diagram)

Power, Current, and Voltage

There is a difference between power, current, and voltage, however they are all interrelated related.

Power: Power is the amount of electricity that something is using at an instant in time. The unit for Power is Watts. Power is equal to the current times the voltage. You need to make sure that you do not exceed 2400 Watts consumption in your house.

Current: Current is how much electricity is "flowing" through the lines. The unit for current is Amperes, often shortened to Amps. Current is equal to the wattage divided by the voltage. You must be sure not to have too much current flowing through the wires. Don’t worry; the circuit breaker will take care of that.

Voltage: Voltage is how hard the electricity is "pushing." Think of when the words "high voltage" are used. They are most often used near lots of electricity. With out voltage, there is now power. The strength of batteries is measured in voltage. (Think 9 volt batteries) Voltage is measured in Volts. More technically however, voltage is the potential difference between two points that makes electricity move. Your house will operate on 120 volts, which is the standard in the USA for AC household power. Internationally, most nations operate on 220 volts for homes.

(equation circle)

Generator and Batteries

Your new home is equipped with a wind generator to collect electricity. When the wind blows, it pushes a set of fan blades which rotates an armature inside the generator. Mounted on the edge of the generator, surrounding the armature is a magnet. When the armature rotates around the magnet, it produces DC current. That current is then fed into a battery system which stores the electricity until it is needed. The battery lets you have electricity even when there is no wind blowing.

When electricity is needed to power one of your appliances, the battery is tapped. However, the power first needs to go through an inverter. This converts the power from the DC current outputted by the battery to AC current which is the type used by your appliances.

The battery is capable of providing a maximum of 2400 Watts at on time. Over a month only 90 kWh of electricity is able to be produced with the generator. The inverter outputs 120 volts AC current at 60 Hz. This is the standard household current in the United States.

Circuit Breaker

The circuit breaker shuts off the power to one or more circuits if too much power is being drawn from the batteries or a short circuit occurs. The circuit breaker is located in the basement next to the battery system. Inside are a small metallic strip and an electromagnet that separate if too much current is going through them. They are like a fuse, except a circuit breaker does not need to be replaced, just flip the switch back. See http://en.wikipedia.org/wiki/Circuit_Breaker for more information

Resetting the Circuit Breaker

If you trip the circuit breaker by exceeding the maximum amount of power supported by the system follow these steps.

1. Find the reason the circuit breaker tripped. You probably added equipment that pushed the sum of all of the appliances that were on at the time over 2400 Watts.
2. Disconnect some unneeded appliances
3. Go down to the basement and find the circuit breaker.
4. Find the switch that is in the off poison. (It will be on the opposite side as all of the other switches.) Push it back to the on position.
5. Verify that all your appliances are working.

Total Power

You can only run a certain amout of electrial equipment at one time. However because an integrated ammeter located on the following devices shuts them off when you turn on another appliance, you do not need to worry about exceeding maximum power draw from the batteries.

• Water Heater
• Water Pump
• Refrigerator

The batteries