Voltage & Voltage drops
The ultimate guide to WHAT IS VOLTAGE & VOLTAGE DROPS? CALCULATION AND ADVANTAGE, The voltage between two points is defined as an electrical force that would drive an electric current between the two points. In other words, it can be defined as the voltage is equal to energy per unit charge. In the case of steady electric fields, the voltage between two points is equivalent to the electrical potential difference between the two points.
• Voltages measured by a device called Voltmeter.
• The unit of voltage measurement is the volt.
Voltage can be understood with the help given figure. Here a voltage source or battery is connected with a load in series. If a +ve potential is placed on one end of a conductor then it will attract negative charges because unlike charges attract. This causes the flow of carrier and hence charge flow. As the potential difference is higher, the attraction of charge is higher, the greater the attraction of electrons causes larger current flow
Fig 1.Voltage representation within a simple circuit
One volt will drive one coulomb (6.24 x 1018) charge carriers, such as electrons, through a resistance of one ohm in one second.
Voltage Drop Calculation
Voltage drop refers to the loss of voltage. Because of the presence of the impedance or passive elements, there exists some loss in voltage value as the current flows through the circuit. That means the energy from the source voltage will get condensed as the current flows through the circuit. High voltage drops may result in the destruction of circuitry and improper operation. Basically, the voltage drop calculation is done by using Ohm’s law.
Voltage Drop calculation in DC Circuits
In DC circuits, the reason for voltage drop is due to resistance. To understanding the voltage drop in the DC circuit, let’s take an example. Consider a circuit that consists of a DC voltage source, a resistor that is connected in series with the load. In this case, every element of the circuit will have a certain resistance, so every element receives and loses some energy. But the deciding factor of the value of energy is the physical characteristics of the elements. When we measure the voltage across the DC supply and resistor, we will find that it will be less than the supply voltage. The current start flowing through the wire starting from the supply voltage to the resistor, and we find that some energy that is transmitted by the source gets dissipated due to the resistance of the conductor.
To verify the voltage drop, Ohm’slaw and Kirchhoff’s circuit award used which are discussed.
Ohm’s law represented as
V → Voltage Drop (V)
R → Electrical Resistance (Ω)
I → Electrical Current (A)
For DC closed circuits, we also use Kirchhoff’s circuit law for voltage drop calculation. It states that: Supply Voltage is equal to the sum of the voltage drop across each component of the circuit.
Voltage Drop in AC Circuits
In AC circuits there is another opposition present for the flow of current that is Reactance (X) which comprises XC and XL in addition to Resistance (R). Both X and R will oppose the flow of current also the sum of the two is termed as Impedance (Z).
XC → Capacitive reactance
XL → Inductive reactance
The amount of Z depends on the factors such as magnetic permeability, electrical isolating elements and the frequency of AC.
In DC circuits, Ohm’s law is given as
E → Voltage Drop (V)
Z → Electrical Impedance (Ω)
I → Electrical Current (A)
IB → Full load current (A)
R → Resistance of the cable conductor (Ω/1000ft)
L → Length of the cable (one side) (Kft)
X → Inductive Reactance (Ω/1000f)
Vn → Phase to neutral voltage
Un → Phase to phase voltage
Φ → Phase angle of the load
Low Voltage Lighting
Low voltage lighting operates at 30 volts or less. It requires a transformer, situated either integral (part of the fitting) or remote (located in a service area), to steps down the line voltage to either 12 or 24 volts. Low voltage lighting saves too much energy and offers benefits that are not available with line voltage lighting. When it is powered properly, low voltage lighting produces two-and-a-half times as much light as line voltage incandescent lamps produce. For example, we can say that a 50-watt low voltage lamp generates as much light as a 125-watt line voltage lamp.
Single lamp energy savings for every 1,000 hours of operation can reach up to $7.50, based on a kilowatt-hour rate of 10 cents. This capacity of energy efficiency fascinating to use low voltage lighting for general lighting applications. Other important features of low voltage lighting include light quality, design flexibility, safety, and lack of waste. Compare to other lighting technologies, low voltage systems can create the desired ambiance, for the occupied Saenvironment. It’s suitable for uplighting and downlighting.
Low Voltage Landscape Lighting
We can go to cheaper lights without losing quality with low voltage landscape lighting. The equipment used lower power in installation.
Advantages and disadvantages
• Lower Cost – fixtures, bulbs, and electricity are available at a lower cost. Itis more energy efficient as it has more light output per watt
• Wider Selection – Helps to spread of light
• Easier – Easy to installation, required less maintenance, smaller fixture sizes, relocating fixtures
• Safe– less risk of shock, can operate in wet weather, safe for children and pets
There are some disadvantages also related to. It needs to have a transformer installed to reduce the voltage. The bulbs can dim if the cables are not in the proper size. So this type of landscape lighting is best used for domestic areas due to their higher safety ratings and energy efficiency.
Fig.Example of Low Voltage Landscape Lighting
High Voltage Landscape Lighting
High voltage denotes lighting which needs 120V of power to work on.
Advantages and disadvantages
• Bright Lights – best for lighting greater areas and bringing a sense of security
• Fewer Fixtures – the brighter the lights, the fewer fixtures you’ll need
• No Transformer – the lights can work on raw power and there is less chance of dimming.
Following disadvantages also present
• Essential Electrician – It is more dangerous if you don’t know what you’re doing
• More Difficult – relocation, installation is tough, less beam spread control, required bigger fixtures
• Expensive – installation is harder and thus costlier
• More Dangerous – higher risk of shock, doesn’t work well when wet.
Fig .Example of high Voltage Landscape Lighting