Busbar Derating

Please check out the many threads in CR4 using the keyword 'busbar'. Here is one for you : Busbar

• is it indoor or out door,
• plugin or feeder,
• ventilated or totally enclosed
• ,copper or aluminium,
• voltage and frequency rating.
• is it 3 phase 4 wire system,
• neutral size half, full or double?,
• earthing bar size requirement 50% or 100%,
• run length,
• ambient temperature,
• installed at conditioned or non-conditioned area,
• short circuit rating for 1 sec or 3 sec?,
• what is the prefered insulation- teflon or resin.,
• what is requirement of copper purity?

• is it indoor or out door, - idoor
• plugin or feeder, - feeder
• ventilated or totally enclosed - Totally enclosed
• ,copper or aluminium, - Both
• voltage and frequency rating. - Voltage 415, Current - 800A
• is it 3 phase 4 wire system, - 3 Phase , 4 Wire
• neutral size half, full or double?, - Neutral Half
• earthing bar size requirement 50% or 100%, - 50%
• run length, - Max. 4.8 Mtrs.
• ambient temperature, - 30 Deg.
• installed at conditioned or non-conditioned area, - Non conditional area
• short circuit rating for 1 sec or 3 sec?, - 1 Sec.
• what is the prefered insulation- teflon or resin., - Teflon
• what is requirement of copper purity? - 0.9

Thats fine. Now, just call any Busbar supplier or manufacturer and give this details. He will give you the correct information as they have standard products for certain current rating.

The various derating factors are K1-temperature rise,K-2 alloy impurity,K-3 altitude

K-4 thermal capacity variations for different layout(ref.DIN43670),K-5 electrical load capacity for different lay out.

Besides there is up rating factor also like using non metallic black matt finish paint( 20% uprating for AL), different bus arrangement ( up rating up to 18%)

Hence all these are to be considered to arrive at actual size in BB design

You consider 0.8 A / sqmm for Al and 1.2 A /sqmm for CU for simple calculation.

So for 800A (AL bus, 100x10 mm Al )and for (CU bus,75x10mmCU)