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The number of conductors is simply the service amperage divided by the desired wire size's ampacity rounded up if there is a remainder. Example: 1000A service, using 300kcmil conductors at 75 deg C: 300kcmil ampacity in this situation is 285. 1000/285=3.5 Since you can't have 3.5 conductors, you must round up to 4. This would give you a total ampacity of 285A x 4, or 1140A. If you're rounding farther than necessary, such as in this case, you can try using the next smallest conductor and adding another set to closer match your required ampacity. 250kcmil ampacity is 255. 1000/255=3.92 We will also round this up to 4, but we aren't rounding as far as the earlier example. The total ampacity is now 1020. 250kcmil x 4 sets is probably the best arrangement for this 1000A service. You could use larger wire and fewer sets, but smaller wire is more cost effective for both ampacity per pound and labor costs for installation.

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16y ago
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6mo ago

The number of conductors per phase depends on the type of electrical system being used (e.g., single-phase or three-phase) and the specific application requirements. In general, for balanced three-phase systems, there are typically 3 conductors per phase. However, for single-phase systems, there is usually 2 conductors per phase.

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9y ago

It depends on the maximum current to be supplied. Wire tables give the maximum current (ampacity) that wires of different sizes can take. For permanent installations with constant load current it is common to limit the current to around half of the values give in the tables, because an appreciable temperature rise means significant power losses.

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15y ago

To calculate the wire sizes for the feeders for motors you have to know the motor's full load amperage which can be determined from the motor nameplate.

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Q: How do you determine the number of conductors per phase?
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How much amp equals 100kw with 3 phases 380 volts?

Do you mean 'per phase' or do you mean 'per line'? The conductors that connect a three-phase supply to its load are called 'lines' not 'phases'. If you mean 'per line', and the load is balanced, then you can manipulate the following equation to make the line current (IL) the subject: power = 1.732 EL IL (where EL = line voltage = 380 V) If you really DO mean 'per phase', then it's necessary for you to specify whether the load is star (wye) or delta connected.


In a 3 phase 3 wire system what is the polarity of each conductor?

In a 3-phase 3-wire system, each conductor does not have a fixed polarity. The phase relationship between the conductors determines the direction of current flow, which can change over time as the phases alternate.


How much current per phase will a 18KW motor draw on 415 v?

To calculate the current per phase, use the formula: Current (I) = Power (P) / (Square Root(3) x Voltage (V)). For an 18kW motor at 415V, the current per phase will be: 18,000W / (1.732 x 415V) ≈ 24.5A per phase.


What size isolator for an 11kW 3 phase motor?

For an 11kW 3 phase motor, you would typically need a isolator with a current rating of at least 18-20 amps per phase. It's important to also consider the starting current of the motor and select an isolator that can handle the motor's inrush current. Make sure to consult with a qualified electrician to determine the appropriate isolator size for your specific application.


If a 240v circuit hsa 30 amps per phase what is the amperage 30 or 60?

If a 240V circuit has 30 amps per phase, the total amperage would be 30 amps. Since the current is measured per phase in a three-phase circuit, you would have 30 amps on each phase, totaling 30 amps.

Related questions

What is phase and why it is used?

Phase is the mathematical relationship between one or more current carrying conductors from the same power source. It isn't "used" per se.


Is three phase transmission line is example of bundle conductor?

'Bundled' conductors describe a line in which two or more conductors are supported from the same insulator chain. In the UK, 275-kV transmission lines typically use two conductors per line, and 400-kV transmission lines typically use four conductors per line. The purpose of bundling conductors is to spread the electric stress on the conductors (e.g. for four conductors, the same amount of electric flux will be 'shared' between the four conductors, rather than concentrated on the surface of one conductor).


What is the definition of electrical capacity?

The amount of conductors per conduit size example code says 3 number 4 conductors in a 1'' conduit


How to Calculate three phase watts with unbalanced phase current?

You will need to determine the power per phase, and add them up to give the total power of the three-phase load. To do this, you will need to multiply the phase-voltage by the phase current by the power factor -for each phase.


What is concentrated winding?

a winding is called concentrated winding when the number of slots per pole per phase is fractional


How do you determine the number of senators?

There are always 2 per state!! :)


Is the kva rating of a three phase generator per phase or a total of the three phases example is a 3 phase 75 kva generator 25 kva per phase or 75 per phase?

The kV.A (not 'kva') rating is the total apparent power of the machine. So a 75 kV.A machine is 25 kV.A per phase.


How do you calculate voltage regulation of 33kv and 11kv distributions?

Regulation =(Obtained voltage per phase - rated voltage per phase)/rated voltage per phase *100


What is determine by the census that is taken every ten years?

The number of house seats per state.


What is the US census used to determine?

How many representatives a state has


3-phase voltage is 400 then per phase voltase?

400V


What are standard speeds of single phase motors?

Single Phase motorRPM (Revolution Per Minute) depends on Frequency used & the number of poles of motor.So this RPM of single phase motor usually 300 to 3000 depending upon F & P.