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What is the acceptable insulation resistance megger reading of 160 linear feet of 350 MCM copper underground cable phase to phase phase to neutral and phase to ground?
Wiki User
∙ 11y ago
Engineers that I have worked with state in their specifications that all meggered wires must have a reading of 5 Meg ohms or higher. If the reading is lower that this benchmark start checking splices especially if it is an underground installation. Water usually accumulates in underground conduit systems and when the wires are pulled in there is a certain amount of conductor scraping. This starts the downward spiral from infinity. Check termination points close to the exit point of the conduit. A certain amount of evaporation from the conduit condensates on the terminal points.
Wiki User
∙ 11y ago
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Can you use ohm-meter to measure a resistance between the neutral line N and the ground E?
If the meter is sensitive enough and there is a resistance between the neutral and ground then the meter should be able to detect it.
How do you earth in the 1600 kva transformer?
In 1600 kva transformer we provide NGR (Neutral grounding resistance)
Can you use HT cable in place of Lt cable?
For LT cable 1. Use : Up to 690V 2. Insulation : PVC 3. Core(Neutral) : Yes 4. Insulation Grading : 1100 V For HT cable 1. Use : Above 690 2. Insulation : XLPE 3. Core(Neutral) : No 4. Insulation Grading : Above 3.3kV, 11KV..etc ( Please note that now 690 V using in VFD application with LV cable and 440 V for DOT motor starter) from Kunal Singh Dabi the_dabi@rediffmaill.com
How can you do the polarity test of a switch?
A 'polarity test', as it applies to a switch, is performed to confirm that the switch is located in the line conductor and not in the neutral conductor.
How calculate the leakage of the capacitor?
leakage current can be determine through the use of clampmeter or ohm-meter. leakage current can be determine through the use of clampmeter or ohm-meter. You can use Ohm's law (E=IR) to get this answer. Disconnect power to the circuit, and measure the leakage path's resistance (This is usually the rated resistance of the insulating material...you will need a M-ohmmeter to measure insulation resistance, as it will be MUCH higher than a standard ohmmeter can measure). Then rework the formula to solve for current: I=E/R or simply: divide voltage by resistance. You can also use an inductive current clamp as mentioned above. This clamp measures electrical current by measuring the electromagnetic field strength of the current flowing through the wire.
What is Dielectrical Insulation withstand level?
for 11 kv non effectively neutral earthed system what is basic Insulation level required?
What size neutral conductor for 100 amp panel?
#2 Copper with TW insulation is required for 100 amp loads #3 Copper with R90 insulation is rated at 105 amps.
Can you use ohm-meter to measure a resistance between the neutral line N and the ground E?
If the meter is sensitive enough and there is a resistance between the neutral and ground then the meter should be able to detect it.
How neutral brings the power to the source?
By creating a loop of equal resistance
What is the reason why the neutral is not used on high resistance grounding?
The question doesn't provide enough detail to give a definitive answer. The neutral PD is often used in protective functions on high resistance grounded generators (when grounded through a transformer). High resistance grounding limits the use of transformers - you must be using balanced loads, since very little current will flow (typically around 5-20amperes max) to the neutral. Because of this, phase to neutral values (such as voltage) are meaningless. Any current flowing in the neutral will cause an offset in all three phases from neutral. Since the neutral is high resistance grounded, it does not take a significant amount of current to cause significant offset.
Which charge do insulators have?
they are neutral. they don't posses any free electron or holes in them, that quality of them makes insulation
Which is hot ribbed wire or smooth wire?
In North America the neutral has to be identified as such. On a lamp cord the ribbed insulation side is the identification of the neutral wire. The "hot" conductor of the lamp cord is the smooth insulation.No. Screw material is no safe indicator because they would be too easy to swap round.
What is the resistance between phase and earth?
You measure at a socket, you should measure well less than one ohm resistance between earth and neutral. .my answer: theoritically it is zero
How do you earth in the 1600 kva transformer?
In 1600 kva transformer we provide NGR (Neutral grounding resistance)
Why does a 3 pin plug have big ground pin?
Resistance =pl/a where a is "area". And area is directly propotional to lenght and thickness. so if the area is greater mean resistance is less. and resistance is inversly proptional to current. so it will act as low resistance path for neutral current.
What is the problem when some house lights are bright and others dim?
Check the neutral connections. An open neutral or a high resistance neutral can cause this type of condition. The obvious place to start your search is in the switch boxes that connects to the light fixture.
How do you reduce neutral and earth voltage up to 0 volts?
If you are reading a voltage it is the drop across the resistance to ground. To get rid of the voltage get the resistance lower. This can be accomplished by installing more ground rods to the grounding system. Utility companies usually like 3 ohms to ground or less.
