What causes voltage drop to increase?
Excessive dropping is due to increased resistance in a circuit, typically caused by an increased load, or energy used to power electric lights, in the form of extra connections, components, or high-resistance conductors.
The four chief variables involved in voltage drop include the wiring material, diameter, and length, and the amount of current being carried. The current carrying capacity of a wire is often called ampacity, which stands for ampere capacity.
Since voltage is directly proportional to the current flowing through a resistance (Ohm's law), which means voltage increases as current or resistance increases.
Voltage drop occurs due to impeding circuit elements (that oppose the current flow) like resistor, inductor, capacitor, etc. Potential difference occurs due to elements that are the source of emf like cell, battery, etc. Voltage drop occurs across a particular circuit element.
- Decreasing Temperature of Conductor. In regards to the flow of power, high temperatures of conductors will resist the flow and will cause the voltage drop percentage to rise. ...
- Decreasing the Length of Conductor. ...
- Increasing Quantity/Size of the Conductors. ...
- Reducing the Power Load.
Higher Amps Increase the Voltage Drop
All electrical cables provide some resistance to the circuit flow, but it is important to take whatever steps you can to decrease that resistance when you're designing your electrical system.
As load current increases, the voltage drop in the wiring increases and the voltage delivered to the system drops. The traditional approach to solving this problem, remote sensing, regulates the voltage at the load, increasing the power supply voltage to compensate for voltage drops in the wiring.
310.15 offers a method to calculate conductor ampacity. The voltage loss is increased when a conductor is operated at a higher temperature because the resistance increases.
Potential Damage to Cords and Wires
“Regardless, this reduces the life of the wire or cable and can lead to other safety issues. Excessive heat build-up can also degrade the conductor material and result in an increase in resistance, which compounds the issue, causing more voltage drop and more heat.”
Voltage drop becomes important when the length of a run of wire or cable becomes very long. Usually this is not a problem in circuits within a house, but may become an issue when running wire to an outbuilding, well pump, etc.
What happens if voltage drop is too high?
Excessive voltage drop in a circuit can cause lights to flicker or burn dimly, heaters to heat poorly, and motors to run hotter than normal and burn out. This condition causes the load to work harder with less voltage pushing the current.