Question

how to measure the voltage drop?

Answer 1

Voltage drop under typical operating conditions can easily be measured. If excessive voltage drop is suspected in a circuit, follow these steps:

Breaker Box 30 ft. 115 120 Source Receptacle Voltage Lost 120-115= 5 Volts

1. Turn on all the electrical equipment which is normally in operation at the time excessive voltage drop is suspected to be a problem.

2. Measure the voltage at the service panel that supplies the circuit in question. It should be 234 volts or more between hot conductors and 117 volts or more between hot and neutral of a 120/240 volt, single phase system (maximum of 3% voltage drop on service drop). If not, call the utility.

3. Measure the voltage at the service panel board with the problem circuit. It should be 227 volts or more between hot conductors and 113.5 volts or more between hot and neutral of a 120/240-volt, single phase system (maximum of 3% voltage drop on feeders, 2% maximum recommended).

4. Measure the voltage at the problem piece of equipment. It should be 220 volts or greater between hot conductors of a 240-volt circuit or 110 volts or greater between hot and neutral of a 120-volt circuit (maximum of 3% voltage drop on the branch circuit back to the service panel board).

Answer 2

using ammeter

Answer 3

A Voltmeter (set to either a.c. or d.c. depending on the supply) is used to measure potential difference or "volt drop". You place the meter across the load (in parallel). This will give you the voltage reading. But to measure 'volt drop' you will either be making multiple measures of voltage along a series circuit or introduce a variance in input to the circuit with regard to the resistance, impedance, inductance or similar and measuring the resulting change in voltage.

Most commonly 'volt drop' testing is employed as easy way to "pressure test' series circuits with common and multiple elements. Such as d.c. motor field and armature windings.

Answer 4

By 'switch' I'm guessing you mean the selector switch on your multimeter. If it's a DC circuit, it needs to be set to 'DC Volts'. If it's an AC circuit, it needs to be set to 'AC Volts'. It's usually a good idea to start with the highest range setting either function and then reduce the setting until you get a useable reading.

When talking about 'voltage drop' there must be current flowing in the circuit. If there is no current, there can be no voltage drop across any element of the circuit.

To measure the voltage drop across an element of teh circuit, connect the meter leads directly across the terminals of the element.

Answer 5

Voltage drop is the reduction in voltage between the source of the electric current and the load point. Voltage drop occurs due to the resistance of wires (conductors) in a circuit and can be computed as the product of the resistance across the cable and electric current.

V=I*R where R is resistance of conductor and I is curren through conductor

Answer 6

Voltage drop describes how the supplied energy of a voltage source is reduced as electric current moves through the passive elements (elements that do not supply voltage) of an electrical circuit.

Answer 7

Voltage drop describes how the supplied energy of a voltage source is reduced as electric current moves through the passive elements (elements that do not supply voltage) of an electrical circuit. Voltage drops across internal resistances of the source, across conductors, across contacts, and across connectors are undesired; supplied energy is lost (dissipated). Voltage drops across loads and across other active circuit elements are desired; supplied energy performs useful work.