Hi all

Has any one looked at the type of electronics used in my 40 years with Telstra PMG ome across a electronics that were very voltage sensitive plus or minus one volt NO voltage spikes or surges and it would fail so batteries or capacities to smooth power supply and fans to keep them cool and happy were required

Could explain the differences

Doug moyle retired end 2003

From:tramsdownunder@... tramsdownunder@...> On Behalf Of TP
Sent: Monday, 15 August 2022 12:25 PM
To: TramsDownUnder tramsdownunder@...>
Subject: Re: [TramsDownUnder] Re: Power substations

The problem, as with many comparisons, is the lack of matching information about the things you're comparing. You can get certain stats about one and an overlapping set of other stats about the other, but not a common set for both. I would like to know what would be the current draw on acceleration of a Skoda 15T or a set of Tatra T3s. The only clue I ever got is when I asked once whether the fast acceleration of Prague trams resulted in higher operating costs and was told that the difference was so tiny they stopped measuring it years ago, so that suggests it's not a big issue for them and they often have multiple trams accelerating together with their stops holding two trams. Yet it's an issue in Melbourne?

Tony P

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

On 15/08/2022 09:53,peterm...@... mailto:peterm...@gmail.com 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