Yes permanent series is not unknown in heavy rail also. NSWGR used two 750 volt motors in series on 1500 DC on some cars. However as you said no transition steps necessary.

It will be interesting to see how waterproof the motors on the Gs are. The trams in Sydney seem to be frightened of water.

Geoff O.

From:tramsdownunder@... [mailto:tramsdownunder@googlegroups.com] On Behalf Of Mal Rowe
Sent: Monday, 18 March 2024 12:03 PM
To:tramsdownunder@...
Subject: Re: [TramsDownUnder] "Chopper Controls"

On 18/03/2024 11:30, 'Geoff Olsen' via TramsDownUnder wrote:

To answer another of Mick’s questions DC electronic drives, regardless of the technology used, eliminate the need for any form of transition steps. The motors are usually permanently connected in parallel.

I think that PCC cars all used 300V DC motors permanently coupled in series pairs - and no series/parallel switching. MMTB wiring diagram attached.

The modern adoption of AC induction motors with no commutator and where speed is controlled by frequency enables motors to be waterproof, as in the Skoda motors that will be in the Melbourne G class trams.

See: https://tdu.to/m/288585

Mal Rowe in a city buying from the Czech Republic!