What is the size of the busbar conductor installed in Canalis KBA Busbar Trunking systems? It is required to calculate the voltage drop.

The voltage drop is not only dependent on the cross section but also on the shape of the conductor and busway design. For that reason, we are proposing directly the voltage drop values in our catalogues.

Attached, you can find 2 catalogue extracts, with the KBA and KBB electrical characteristics, including voltage drop, and also the 2 specific pages concerning voltage drop for lighting distribution (KBA and KBB) with tables for a direct overview of voltage drops and %.

The voltage drop is depending on:
- Product characteristic => catalogue
- Cos ϕ (cos phi= generally 0.8 for lighting)
- Length of the run
- Network voltage to find % of DU

Example on a KBA25A, loaded with 16A in total, well splited along the length 30meters. Cos ϕ =0.8:

From the electrical characteristics, the voltage drop for such power factor - Cos ϕ = 0.8 is: 0.61 V/100 m/A

So voltage drop is: delta U = 0.61 x 30 meter x 16A / 100 = 2.928V  (or 2.9 direct access in the table)

This voltage drop in a 230V lighting system leads to 2.928/230 = 1.27% of voltage drop. That’s acceptable

Note: Voltage drop isn’t dependent of connectors or feed units, only length of loaded busways is necessary.

Released for:Schneider Electric South Africa