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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.
Wiki User
∙ 15y ago
Wiki User
∙ 9y agoIt 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.
Wiki User
∙ 14y agoTo 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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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.
When is the measurement of turbidity a reliable indication of the number of viable cells per ml?
It is reliable for validity only when most of the cells are still valid (alive); therefore before the stationary phase (in the Log or Lag phase it would be viable).
What is dynamic stability in a three phase motor?
Dynamic stability is the property of retaining almost the same number of revolutions per minute when the mechanical load on the shaft is connected or diconnected.
What is unusual about the phase change of naphthalene?
if napthalene absorbs energy at 250j per minute how much energy is lost to effect the phase
Where the volatage is measured in the three phase systems?
You can use wattmeters to measure three-phase power. According to 'Blondel's Theorem', you can use one less wattmeter than there are conductors connecting the load to the supply. So, for a three-wire system, you can use two wattmeters but for a four-wire system, you must use three. Check out 'three wattmeter method' and 'two wattmeter method' on the internet to find the necessary connection diagrams.
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.
How do you determine the number of senators?
There are always 2 per state!! :)
What is concentrated winding?
a winding is called concentrated winding when the number of slots per pole per phase is fractional
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.
