wire diameter for heating element

[yamatan]

Am making a large kiln.

3 phase, 24.75 KW, 65 amps, 220 volts

seven "Y" connection, or 21 rows of elements in all.

coil length is 46 inches. Rod diameter is 25 mm.

Question:

What is the best wire diameter should I use? The maximum temp is only 1800 F. Need the coil to last ten years,


Thank you
nelson tan

 

[dydt]

questions:

is each heater rated 220volts? how many watts?
do you really need to use 220V instead of 440V?..using the higher voltage will reduce the wire and fusing size and will be more cost effective..

in practice heater banks are commonly connected in delta and not "Y" because of stability and convenience of trobleshooting..

dydt

 

[yamatan]

Thank you.

1178 watts per row

220 volts is already available in our place.

I will use delta connection now because a lot of people are suggesting it also. Thank you