Hi Mal,

Thanks the picture is worth 1000 words. The 2 feeder wires in the middle
in parallel with the 2 contact wires bode far better at the 1500A current
draw.

Thanks
Peter

On Monday, 15 August 2022 at 10:32:05 UTC+10 Mal Rowe wrote:

> On 15/08/2022 09:53,peterm...@... wrote:

> > 1500A on a 600V overhead, is not good in terms of voltage drop. Ive

> > not been to Melbourne for a while, is it still a single contact wire,

> > or are there dual contact wires and additional feeder wires like

> > railway approach to reduce voltage drop?

> >

> There are multiple feeder cables throughout the system and no places

> that I am aware of where there is noticable voltage drop.

>

> I was told at a safety briefing by Yarra that the trip current from a

> substation is usually set at 2500A - meaning that up to 5000A is

> available in a typical section fed from both ends.

>

> There are no double contact wires that I am aware of, but there are

> places where an extra set of contact wires is hung on the overhead as

> feeders. You can see them in my pic at: https://tdu.to/i/52233

>

> The light rail lines to St Kilda and Port Melbourne still have the

> heavier contact wire and catenary from railway days.

>

> See my pic at: https://tdu.to/i/39803

>

> Mal Rowe - who once knew a bit about Elec Eng

>

>

>

>