Hi Mal & All,

You should be aware that some positive feeders make their way down the overhead structure wiring to a point say half way to the next section insulator.

This is a much heavier cable than the contact wire and is of much simpler although stronger construction.

For longer distances this carrier cable may be hooked into the overhead at more than one place.

The 2 MW rectifiers seem to be a standard size for general tram way use. If you put in higher rating ones then you have to provide cubic $$$ to upgrade the feeders.

Unfortunately a lot of Tony’s plans do not have $$$$ filters, which do not matter in dreamtime, but are essential on the real Tramway system.

Regards
Kevin

From: mailto:petermudie100@gmail.com
Sent: Tuesday, August 16, 2022 9:36 AM
To: TramsDownUnder
Subject: Re: [TramsDownUnder] Re: Power substations

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