Service Entrance/Feeder Conductors

[Kissi Asiedu]

In my country Ghana, most houses have a 3 phase 4 wire system at 220-240
volts. Some if not most electricians use 16mm2 THHN wire to connect from the
service point, through the watt hour meter and to the load center. This is
for 200 amp service. I thought a 200 amp service would require 2/0 cable for
such service. In reference, 16mm2 is equivalent to #6. Is this type of cable
efficient for such service?

 

[Andrew Gabriel]

In my country Ghana, most houses have a 3 phase 4 wire system at 220-240
volts. Some if not most electricians use 16mm2 THHN wire to connect from the
service point, through the watt hour meter and to the load center. This is
for 200 amp service. I thought a 200 amp service would require 2/0 cable for
such service. In reference, 16mm2 is equivalent to #6. Is this type of cable
efficient for such service?

In UK, IIRC (don't have tables on me), 16mm2 tails are for 60A max
service. 25mm2 tails are used for 100A service. Is your 200A service
200A per phase, or 200A total on all 3 phases (in which case 16mm2
would be about right)?

 

[SQLit]

In my country Ghana, most houses have a 3 phase 4 wire system at 220-240
volts. Some if not most electricians use 16mm2 THHN wire to connect from the
service point, through the watt hour meter and to the load center. This is
for 200 amp service. I thought a 200 amp service would require 2/0 cable for
such service. In reference, 16mm2 is equivalent to #6. Is this type of cable
efficient for such service?

#2 out of the NEC for North America table 310-16 75C is 115 amps.
#2 in free air table 310-20 is 135 amps. (75C)

2/0, 310-16 is 175 amps. (75C)
2/0 in free air is 265 amps (75C)

Where I live in Phoenix. Service conductors for a 200 amp service must be at
least 4/0 copper or 250 mcm Al. We MUST use the derating factors at the
bottom of the tables for heat. I like to see all the equipment that I
install outside rated for above 40C preferably 50C. It does get that toasty
here.

I have never done any electrical work other than in North America so your
conditions WILL be different.
If you have 3 phase I am surprised that you need anything larger than 100
amps.