How to Map House Electrical Circuits
Electricity travels in a circle. It moves along a “hot” wire toward a light or receptacle, supplies energy to the device (called a load), and then returns along the “neutral” wire (so-called because under normal conditions it’s maintained at 0 volts, or what is referred to as ground potential) to the source. This complete path is a circuit.
At the electrical panel, turn off all of the circuit breakers.
Identify any large, double (240-volt) circuit breakers first. Flip one on. Determine which major electrical appliance(s) it supplies by turning on each electrical appliance (don’t forget equipment such as the furnace and the pool pump) until you find the right one(s). Repeat with the other large circuit breakers and major appliances.
Have your helper plug a small lamp (or any small electrical device) into a standard room receptacle. Turn breakers on and off until you find the one that turns on the device. Leave that breaker on and have your helper plug the device into other receptacles; note all the ones controlled by that breaker.
Repeat this process, switching on room lights one by one, and note the circuit breaker that controls each set of lights.
Helpful Tips On Mapping Your House Electrical Circuits
Mapping your home’s circuits is essential for verifying which devices is connected to each circuit and is determined by shutting down the breakers one by one.
Understanding Your Circuits
Each electrical panel has electrical wiring that carries voltage running to and from the electrical outlets. Hotwiring transmits electricity from the breaker box to the electrical outlets, lights, and other devices. The neutral wiring carries the power back. When a breaker is flipped, a circuit is interrupted, making it safe to work on. The circuit map on your electrical panel will indicate the different circuits which are labeled “bathroom,” “living room” etc.
In some cases, light fixtures will be on one circuit and your wall outlets on another.
Where To Start
Mapping your electrical panel will require two persons, one at the board itself and the other on walking around, communicating with walkie-talkies or cell phones.
The circuit breakers must be clearly numbered before starting.
The person walking around must have a notepad, pen and outlet tester.
Switch on all lights, electronics, and appliances except for computers that need to be shut down correctly.
The person at the panel must start shutting down the breakers, one at a time, beginning with large double-pull breakers which control large appliances such as air conditioners, oven dryers, etc.
The person moving around should then check which lights or devices are deactivated by using the outlet tester. All nearby lights and outlets must be checked to confirm that they’re completely dead.
Take detailed notes every time you’ve determined what is running on a circuit. An extra helpful step would be to remove each switch plate and outlet cover and write the breaker number on the back of each before putting it back. This way, if an residential electrician needs to perform repair work, they can immediately see which breaker must be switched off.
Tips for Water Heater Circuits
Everyone enjoys a nice warm shower or bath and we all take hot water for granted when we shave or wash our dishes. In most parts of the modern world, a good water heater in an indispensable item. However, if a water heater is wired improperly or installed on a circuit that can’t handle the load, it can be dangerous. A water heater is also filled with water under pressure and is powered by electricity and as we all know, water and electricity do no mix. If something goes wrong with the water heater, it can become a life-threatening situation. Also, if installed improperly, the pressure inside the water heater can turn it into a big bomb essentially, waiting to damage your home and cause injuries. Knowing all this, it is easy to understand why having your water heater wired properly and installed correctly is very important.
House voltage in Australia is normally between 220v and 240v and the electrical wiring and main breaker for the water heater should be about 30 amps, or more depending on the requirements of the heater you select. Some Water heaters may use more and some may use less but the circuit that supports the water heater should normally be rated at about 30 amps. This will insure that you can install most types of home water heaters and not surpass the rating of the circuit. You don’t want to install a circuit that can support exactly the maximum requirement of the water heater. You want the circuit to be rated higher than the water heater so there is no chance it may overload. Most smaller items that are used near water need to be plugged into outlets that have ground fault circuit interrupters (GFCI) otherwise known as residual current devices (RCD). An RCD safety switch must be installed with your hot water-heater to keep it safe incase somehow the electrical components contact the water. An RCD will interrupt the power and protect the people using the water if something goes wrong.
Electricity: Electric Circuits
Electric Circuits: Problem Set Overview
This set of 34 problems targets your ability to determine circuit quantities such as current, resistance, electric potential difference, power, and electrical energy from verbal descriptions and diagrams of physical situations pertaining to electric circuits. Problems range in difficulty from the very easy and straight-forward to the very difficult and complex. The more difficult problems are color-coded as blue problems.
Current
When charge flows through the wires of an electric circuit, current is said to exist in the wires. Electric current is a quantifiable notion which is defined as the rate at which charge flows past a point on the circuit. It can be determined by measuring the quantity of charge that flows past a cross-sectional area of a wire on the circuit. As a rate quantity, current (I) is expressed by the following equation
where Q is the quantity of charge flowing by a point in a time period of t. The standard metric unit for the quantity current is the ampere, often abbreviated as Amps or A. A current of 1 ampere is equivalent to 1 Coulomb of charge flowing past a point in 1 second. Since the quantity of charge passing a point on a circuit is related to the number of mobile charge carriers (electrons) which flow past that point, the current can also be related to the number of electrons and the time. To make this connection between the current and the number of electrons, one must know the quantity of charge on a single electron.
Resistance
As charge flows through a circuit, it encounters resistance or a hindrance to its flow. Like current, resistance is a quantifiable term. The quantity of resistance offered by a section of wire depends upon three variables – the material the wire is made out of, the length of the wire, and the cross-sectional area of the wire. One physical property of a material is its resistivity – a measure of that material’s tendency to resist charge flow through it. Resistivity values for various conducting materials are typically listed in textbooks and reference books. Knowing the resistivity value (ρ) of the material the wire is composed of and its length (L) and cross-sectional area (A), its resistance (R) can be determine using the equation below.
STC Program: Electric Circuits, 3rd Edition
In Electric Circuits, students investigate electricity by wiring a circuit to light a bulb and learn that a circuit must form a complete circle through which electric current can pass in order to light the bulb. They explore other electrical concepts, such as what conductors and insulators are and how they work. Students also learn about the symbolic language of electricity and use it to read and draw diagrams for wiring circuits and constructing a flashlight.
