Combiners, Circuit Breakers, Electrical Distribution, Wire, Cables
CIRCUIT VOLTAGE AND CURRENT Protection Devices
Each year, dozens of homes in this country are burned to the ground due to fires as a result of faulty electrical wiring. Millions of dollars worth of properties and even people's lives are lost in some cases. What's worse is that most of these accidents could easily have been prevented had the homeowners given more attention to electrical wiring safety through the proper use of combiners, circuit breakers and other UL listed electrical distribution protection.
- Electrical Distribution
- Life Saving Tips Working With Electricity
- Instructional Videos
- Installation Guides:
Considering Solar Array Components
Solar panels produce direct current. Controllers, batteries, monitors, fuse boxes, inverters and circuit breakers using the overall electrical distribution help transfer that current into a grid tie or off-grid home. For off-grid applications, from the solar panel, electricity should travel to a combiner to a charge controller to a battery bank. The controller helps manage the amount of electricity entering the nodes. When the battery is fully charged, the current from the panel is either restricted or can be diverted somewhere else such backfeeding in some cases to the utility grid. Photovoltaic systems with battery banks give homes the flexibility of using stored electricity during grid outages which otherwise with a grid-tie system would stop functioning without the grid.
WARNING: SHOCK HAZARD: It is the responsibility of the purchaser to ensure that all products are installed and operated in accordance with local and national building codes as specific by the NEC (National Electric Code), UBC (Uniform Building Code) or IBC (International Building Code) and local utility company policy. These codes may vary from city to city and county to county. All grid-tied as well as off-grid solar installations should be permitted and inspected, where required, by the local inspection authority having jurisdiction in the same manner as other equivalent electrical systems. Blue Pacific Solar recommends you contract with a local licensed electrician to do the final electrical distribution and final connection of your solar system from the AC disconnect to your home utility breaker box. Some local permitting authorities require that a licensed electrician do all the wiring from the rack to the utility interconnect. If you need help with the permitting documents for your kit, we are here for you. Solar permit service add on is available at checkout.
Series and Parallel Circuits
An electric circuit is composed of one or more electrical components hooked up to a voltage source such as a battery. There are two different ways to hook multiple components up to the same voltage source: in series and in parallel. Each circuit type causes its components to behave differently. The fundamental law of electronics, Ohm’s Law, relates the voltage, current and resistance in a circuit. Once you understand how these quantities operate in both types of circuit, you have a solid grasp on the basics of electronics.
Series circuits have all the components joined together in a line. The free ends of the line, or “terminals,” are hooked up to the terminals of the voltage source. Parallel circuits have a number of different “branches.” Each branch contains one or more components hooked up in series. Each terminal of each branch is connected to the battery terminals.
All the current that is produced by the battery flows through each component of a series circuit, one after the other. The current in a series circuit flows through every component. The current splits at each branch of a parallel circuit, with each branch getting a portion. None of the current in a parallel circuit flows through every component.
The voltage of each branch of a parallel circuit is equal to the voltage of the power source. For example, if three branches of a parallel circuit are connected across a 12 volt battery, then each branch experiences 12 volts. If seven branches of a parallel circuit are in a device plugged into a 120 volt outlet, then each of the seven branches experiences 120 volts. On the other hand, the voltage of a power source is divided up between the components of a series circuit. The amount of voltage each component gets is proportional to its resistance. For example, consider three components that are hooked up to a 12 volt battery. One of the components has 100 ohms of resistance and the other two each have 50. The 100 ohm component experiences 6 volts, and the other two experience 3 volts apiece.
The total resistance of a series circuit is equal to the sum of the resistances of each electrical component. This is because all of the current flows through all of the resistors, one after the other. The total resistance of a parallel circuit is lower than the resistance of any of its branches. This is because there are more paths for the current to take, so it spreads a little out through each resistor. No part of the current goes through all of them. To find the total resistance of a parallel circuit, divide the number one by the resistance of the first branch. This is called “taking the inverse” of the resistance. Take the inverse of all of the branches. Add the inverses together. The total resistance is the inverse of the result. For example, consider a parallel circuit with 100 ohms of resistance in each of two branches. The inverse of each is 1/100, or 0.01. Adding them together is 0.02. The inverse of this is 50, which is the total resistance of the parallel circuit.
Doing your own home wiring or solar electrical distribution is very rewarding and can save you a lot of money. While you must always use caution when dealing with any kind of electricity, special precautions working with DC as well as AC electrical circuits need to be taken to avoid serious injury and death. The following three steps must always be taken before working on any project in your home.
Step one: Before starting work make on your electrical connections, make sure to turn all circuit breakers completely off. This prevents any electricity from traveling down to the wires you will be working on. Once you have done this double-check it to make sure that it is turned all the way off. This step cannot be stressed enough, and is the biggest safety step you can take when working with any voltage to prevent injury. Once you have completed the second check of the breaker box, perform a third check with a voltmeter at the line you will be working on. If everything is properly shut off put a sign over the circuit breaker warning others that you are working further down the line, and not to touch any of the breakers.
Step two: Make sure you use insulated tools when working with any electrical wiring in your home. While they will not provide a great deal of protection in the event of an electrical shock, a good set of insulated tools could mean the difference between a nasty shock and death. Rubber-soled shoes are another must have item when dealing with high voltage. In order for electricity to damage your body, it must travel through you and into a ground. A ground is simply a place for the electricity to drain out, which in most cases is the ground below your feet. While the electricity is arcing through your body to reach the ground, it passes through your brain and heart, interrupting the electrical signals of those organs. This is the cause of most electrocution injuries, although you can also suffer severe burns at points where the electricity exits your body. If you are wearing a pair of well-insulated boots, or are using a rubber-handled screwdriver, the electricity can't make a full connection through your body, which makes you a lot safer.
Step three: Make sure you followed step one to the letter. This is listed a second time because failing to properly shut off power is the leading cause of death in home electrical repair. All other safety precautions will not mean anything if you do not shut the power off before you begin work.
Following these three steps before you begin any electrical work in your home will not only help you quickly get the job done, but help to keep you safe as well.
NOTE: We always recommend you employ the services of a licensed local electrician or other properly trained and qualified persons to complete any final connection options prior to commissioning any electrical system.
Electrical Distribution; Getting to Know a Solar Array
When it comes to solar installations, business is booming. With plummeting costs, increasing efficiency, and plenty of government incentives, more homeowners are considering solar power every year. Electrical Distribution, DC current, PV wire circuit breakers and main panels, it's time to get to know a solar array.
A solar array is first and foremost a collection of solar panels. Each of these solar panels consists of a collection of individual solar cells. These solar cells are simple slabs of specially treated crystalline silicon. During the manufacturing process, trace elements are added to the silicon mixture, leading to an overall positive or negative charge in the material. One half of a solar cell is formed from the positively charged mixture, and the other half from its negatively charged counterpart.
Once the two halves are joined, a flow of electrons from the positively charged side streams towards the negatively charged half. Eventually, a neutral barrier will form between the two halves, halting the electrical flow. When the cell is exposed to sunlight, photons from the sun's rays strike the solar cell, knocking electrons loose from their atoms and disrupting this neutral barrier enough to restart the electrical flow.
Multiple solar cells are then fitted next to one another and enclosed within a frame, becoming a single solar panel. In order to harvest the electrical flow from the cells, a network of metallic wiring is installed, connecting with each individual cell and leading to a larger wire at the edge of the panel. This large wire terminates in a socket on the frame, which will be used to connect each individual solar panel into the overall solar array via Electrical Distribution; combiners, circuit Breakers, wire and PV cables.
At this point the electricity from the solar panel is flowing as a Direct Current, or DC. This means the electrical flow is moving in a single, continuous direction. Modern standards for usage of electricity require an Alternating Current, or AC. In contrast to DC power, AC power "cycles" the direction of its flow back and forth dozens of times every second. This constant reversal "tames" the current, allowing it to be more easily manipulated and monitored by the various components of an electrical grid.
In order to convert the DC power flowing from the panels into AC power suitable for the home's wiring, an inverter is used. This device will impose the required AC power cycling onto the existing DC electrical flow. In some systems, each individual solar panel will be wired to a single inverter that handles this conversion for the entire solar array. An alternative exists in the form of "micro-inverters," which are simply smaller inverters that handle the AC power conversion for each individual solar panel.
Once the electrical flow has been converted to AC power it's ready to enter the home. In solar installations that do not include battery storage, this happens immediately. The power will flow from the inverter into the home's existing electrical meter, and will either be distributed into the home's wiring, or diverted back to the power company's electrical grid if it's not required at that moment.
Solar arrays that are off the grid or otherwise make use of a battery storage system require an additional step before being fed into the batteries. If the home's meter decides that the electricity is not required immediately, it will be diverted to a Solar Charge Controller, also known as a Battery Controller. This device regulates the flow of electricity to and from the system's batteries, ensuring that each individual battery is charged and discharged in a safe and regimented manner.
Through this process a small amount of electricity harvested from an individual solar cell can be combined with many others into solar panels and via electrical distribution the overall solar array in order to provide for a grid tie or off-grid home's energy needs.