Class 323 motor sounds

[straller]

Hello everyone,

Is there anybody in here who knows why does the Class 323 sound like that? What's the secret of it's unique GTO inverter that makes sounds like that?

 

[thenorthern]

Three phase motors I think that no other trains have, it can cause problems when its raining I think someone said.

 

[Lrd]

IIRC (it's the same for Desiro's) then there are certain frequencies that interfere with signalling equipment, therefore these sounds are "notched" out, causing the motors to change pitch frequently.

 

[Nym]

Three phase motors I think that no other trains have, it can cause problems when its raining I think someone said.

Every new train has 3 phase AC motors and almost any AC motored train has 3 phase machines...

Why a train would not use a 3 phase machine defeats me as it seems to be abject stupidity when a VSD is to be used...

What exactly do you want to know about the sounds?

 

[starrymarkb]

Hello everyone,

Is there anybody in here who knows why does the Class 323 sound like that? What's the secret of it's unique GTO inverter that makes sounds like that?

It's made by Holec (now part of Alstom) - the only UK stock with that kit. Networkers used Brush/Alstom inverters. IIRC those were the only Pre-Privatisation AC Motored Stock.

This Swiss stock uses a more modern version of the Holec AC Packs and the noises are similar (if lower in tone as the Lotschberger is a powerful hill climber)

https://www.youtube.com/watch?v=87WnWhQOxf0

(Departure is 50 seconds in)

 

[transmanche]

IIRC (it's the same for Desiro's) then there are certain frequencies that interfere with signalling equipment, therefore these sounds are "notched" out, causing the motors to change pitch frequently.

Would that also be the reason this OBB Taurus (?) loco seems to be practising scales?

[youtube]d3cdL-HkfIU[/youtube]

 

[Lrd]

Would that also be the reason this OBB Taurus (?) loco seems to be practising scales?

That's a pretty cool sound!

In all honesty, I have no idea, it's only what I think I remember reading these forums, my memory isn't the greatest at the best of times.

Let me see if I can find an old thread with the details in it.

EDIT: Found a thread which confirms my memory. Specifically this post (#7).

 

[tom1649]

Of course the Jubilee Line's 1996 stock uses similar motors.

 

[heart-of-wessex]

I went on a couple of 323's not long ago, sitting in the end cars. The motor's didn't sound that audible inside, even with a hopper window open, yet sound clear when watching from the platform.

Unsure if I was sitting in the right place to hear it though...

 

[yorkie]

Three phase motors I think that no other trains have, it can cause problems when its raining I think someone said.

Who is "someone"? I'd take anything else that someone said may be taken with a pinch of salt

 

[ed1971]

In reply to the OP's original question, in a nutshell, the motor speed on these units is controlled by the frequency applied to them not the voltage. This is controlled by a microprocessor. I believe that the reason for the 'amusement arcade' sounds is the changes of frequency applied to the motors. I have seen Youtube videos of other classes of newer EMUs making similar sounds, but cannot remember which ones.

There are Japanese EMUs that sound similar to 323s. Take a look at this: http://www.youtube.com/watch?v=f40DyfEE9EY