480 V 1600 A switchbox

[frenchelectrican]

hello guys and ladies :

i ran into a good question about using 1600 amp switchboard what i try to find the correct wire size for this appaction ;

5 parelleal cables size 750 MCM will meet the nec code ? or 600 MCM copper and yeah the type will be thhn or xple ( super tough service enterince cable ) and from switchboard to transformer it is 75 meter ( 260 feet) long so if that meet the code i have older code book chart but dont say over 1200 amps so i try to figured out for 1600 amps and it have 5- 4 inch pcv conducts there and the extra one for spare

p.s i will list the motors

3- 150 hp
2- 100 hp
2- 50 hp
5- 20 hp
mixed bags of motors total sum of 20 hp


and i got the figured it came out 1,083 amps so let me know


thanks for your time


merci marc

 

[bennie]

Re: 480 V 1600 A switchbox

You are installing a lot of copper. Can you move the transformer closer to the load?

 

[frenchelectrican]

Re: 480 V 1600 A switchbox

yeah bennie i know it will use alot of copper but my coumster dont want to move the transfomer closer and i told my comuster that it will cost alot more $$$ for it and myself i rather keep it close as possible i will wait for other to reply this post and i will see where i will go next but genrally i try to find the chart and it dont show for 1600 amps so i try the best way to go

merci marc

 

[bennie]

Re: 480 V 1600 A switchbox

Have you considered two 600 amp panels and feeders?

 

[frenchelectrican]

Re: 480 V 1600 A switchbox

yeah i tought about it but you look at the listing for the motors for the pellet mill that what it will set up and i rather leave the panelboard large instead of few smaller one but i will try that idea and i did work on the sawmill before it have 800 amps service and it was not running full load it was loaded about 60% full load so i have more than engough to play around in case for additional equimpents. but this set up will end up have 2 line of pellet mills for sure this will look like this : one large hammer mill (150 hp ) then go to the second mill (100HP) [ it will grind the wood chip smaller each time ] then go to mixer if i recalled it have 20 hp motor on it then finally the exturder it will have 50 hp motor on it that how it will run in the line but there are few small motors along the way { convoyer and etc} that the reason i was planning to use the 1600A switchboard system or go with two 800 amp switchboard's maybe it it cheaper this route but i am not sure but i leave this part open anyone have other idea ??? turn on the " idea " lightbulb here


merci marc

 

[bob]

Re: 480 V 1600 A switchbox

French
Is there any other load?
3- 150 hp @ 480v = 180a x 3 = 540 amps
2- 100 hp @ 480v = 124a x 2 = 248 amps
2- 50 hp @ 480v = 65a x 2 = 130 amps
5- 20 hp @ 480v = 27a x 5 = 135 amps

-----------------------Total 1053 amps

THHN Cables
600 kcm at 420 amps x 4 = 1680 amps
500 kcm at 380 amps x 5 = 1900 amps
500 kcm at 380 amps x 4 = 1520 amps
I you have any other load that will flow in the neutral you may have to derate these cables. Also if you have harmonic loads you will derate the cables.

[ July 30, 2003, 03:36 PM: Message edited by: bob ]

 

[frenchelectrican]

Re: 480 V 1600 A switchbox

hi bob :

yes there are few more motors add on the list : 3- 3 or 5 HP for the convoyer and genral lighting inside the building ( appx 3 kw ) and the boiler which i will add on the list soon i get the answer from the person whom sell the machery for my comumster .. and i did remesure the cable run it is 175 feet and probly use the 500 mcm cable but will bump up to 600 mcm if they have it due the voltage drop and i want to keep the main breaker rating high due large electric motors starting but i did warn my comuster make sure the machine do have "autotransfomer " starter i cant find anything in nec about the starting the motor across the line but i rather be on the safe side it will start unloaded but i want to use the autotransfomer or wye-delta starter if that motor have the connetion for it to keep the current down and leave the panel board plenty big so it have room to add more machines as need .

thanks for your inputs


ps bob the list you gave me is that rated with alum or copper wire ???


merci marc

 

[bob]

Re: 480 V 1600 A switchbox

You might want to compare the price of a solid state starter. It may be cheaper that the other.
This list is for copper.

[ July 31, 2003, 04:49 PM: Message edited by: bob ]

 

[frenchelectrican]

Re: 480 V 1600 A switchbox

thanks bob for suggestion for the solid state starter and i will look into also and i will keep posted here what is the progress


merci marc