350/2s

[TP2000]

Just wondering if you had to shut off power through neutral sections on 350/2? We're going to get some EMU stock and I'm new to it all having only driven DMU for over 10 years. Also the APC on trackside isn't that there to shut the power off via the VCB and reed switch?

 

[notadriver]

Yes always shut off before a neutral section for a smooth ride or the unit will jerk.

 

[transportphoto]

Hopefully you'll receive suitable training and you won't need to ask a public forum!!

 

[notadriver]

Hopefully you'll receive suitable training and you won't need to ask a public forum!!

Was there any need for a reply like that ?

 

[asylumxl]

Was there any need for a reply like that ?

I don't think so.

On the second part of the quesiton, I'm not a driver but I believe there is such a system but I think it's intended as a preventive measure than anything.

 

[TP2000]

No there isn't a need for a reply like that, and I'd like to put his those exclamation marks elsewhere. My training won't start for at least a year it's was merely an inquiry. Thanks for the other replys

 

[notadriver]

Also I think while the APC does open the VCB, if the power is left on through a neutral section it will take longer before you can reapply power after passing through it.

 

[455driver]

As stated the train will jerk and the VCB is not happy switching high currents and will eventually be damaged if it is done too often, its all part of the driving skill that you will be taught.

There are-
the need to know
and the nice to know

and you will ebtaught them all.

I drive on the proper electric system and always shut off for the gaps (where ever possible) just so it is a smooth ride for the passengers and also easy on the mechanicals of the train.

 

[TP2000]

As stated the train will jerk and the VCB is not happy switching high currents and will eventually be damaged if it is done too often, its all part of the driving skill that you will be taught.

There are-
the need to know
and the nice to know

and you will ebtaught them all.

I drive on the proper electric system and always shut off for the gaps (where ever possible) just so it is a smooth ride for the passengers and also easy on the mechanicals of the train.

Cheers 455. Would the VCB be linked to a reed switch if the ACP is magnetic?

 

[455driver]

Cheers 455. Would the VCB be linked to a reed switch if the ACP is magnetic?

Not sure, sorry.

When I say "proper" electric railway I mean the 3rd rail kind not that nasty overhead stuff!

 

[transportphoto]

Apologies for the tone of my previous response, however as I'm sure you may be able to understand, speaking as a passenger, I would hope that appropriate training will be given for the introduction of electric stock and that seeing a driver asking about driving methods on a public forum such as this is slightly worrying.

TP

 

[TP2000]

No worries transportphoto. Believe me when training does start all drivers will be fully competent on the traction they drive.

 

[westcoaster]

Just wondering if you had to shut off power through neutral sections on 350/2? We're going to get some EMU stock and I'm new to it all having only driven DMU for over 10 years. Also the APC on trackside isn't that there to shut the power off via the VCB and reed switch?

1. Yes otherwise you risk drawing an arc through the neutral section.
2. All the apc magnet is for is to open the VCB, there are 2 on the track one to open the VCB and one to close it.
I'll see if I can find a picture of it for you.
--- old post above --- --- new post below ---
Have a look here seems to explain it well, with a good set up picture http://www.trainweb.org/railengineering/ep/dist.html

 

[TP2000]

1. Yes otherwise you risk drawing an arc through the neutral section.
2. All the apc magnet is for is to open the VCB, there are 2 on the track one to open the VCB and one to close it.
I'll see if I can find a picture of it for you.
--- old post above --- --- new post below ---
Have a look here seems to explain it Yerwell, with a good set up picture http://www.trainweb.org/railengineering/ep/dist.html

Cheers westcoaster. I know how the APC work with the VCB I guess then its only there as a precaution if the driver doesn't shut off. Now this VCB on the unit must be influenced by a reed switch then I presume, as a reed switch works by switching on and off by magnetic field.

 

[westcoaster]

Cheers westcoaster. I know how the APC work with the VCB I guess then its only there as a precaution if the driver doesn't shut off. Now this VCB on the unit must be influenced by a reed switch then I presume, as a reed switch works by switching on and off by magnetic field.

Never heard of a reed switch sorry this from our traction guide

The VCB is essentially a large ON/OFF switch located on top of the PMS Coach controlled by air pressure from the Pantograph air system. The VCB is only used when the unit is working in AC mode. When in DC mode the VCB remains open as it is not needed to run the unit on DC.
The contacts contained in the VCB carry a very high voltage (25,000 volts) so they are enclosed in a vacuum to stop arcing, hence the name.
The VCB has its own Governor (not accessible to the driver) which will open the VCB should air pressure to it fall below approx 3.4 BAR. The Governor ensures that the contacts open correctly by de-energising the VCB EP valve. If the governor didn’t do this the contacts would slowly drift open as air pressure fell, causing severe arcing.
To protect the Transformer and hence the unit from possible damage, the VCB opens under fault conditions to cut off the OLE supply from the unit. You can think of the VCB like the main circuit breaker on your houses consumer unit (the one that cuts off all electrical circuits when tripped)
CLOSED
OPEN
25KV from OLE
25KV from OLE
To Transformer
To Transformer
VCB EP Valve Energised
Air from Pan Air System enters Chamber
VCB EP Valve De-energised Air vented from Chamber
When the VCB EP Valve is energised (such as when the ‘Pan Up Set-Reset’ button is pressed, etc) air pressure is allowed to flow into the air chamber in the centre of the VCB. This air pressure pushes the 2 contacts apart and ‘closes’ the connection allowing OLE power to flow through the braiding to the Transformer on the unit and switching the VCB Light ‘OUT’ in the cab.
When the VCB EP Valve is de-energised, air pressure is vented from the VCB (such as during fault conditions, when going through a neutral section or when the ‘Pan Down/DC System Select’ button is pressed) the springs pull the contacts apart, this ‘opens’ the connection cutting off power from the OLE and switching the VCB Light in the cab ‘ON’.

 

[plastictaffy]

I was working a service the other day out of New Street last week. There's a Neutral just outside Berkswell, (not ideally sited, as especially after the Berkswell call, you are trying to pull away on a rising gradient) and the driver did not shut off - there was a massive jerk, and a louder than normal "thump" when the juice went off. It would have been noticeable in the saloon, too, especially as we were full and standing.

 

[TP2000]

Never heaYerrd of a reed switch sorry this from our traction guide

Yer that's seems to confirm what I've picked up so far. Cheers WCR, wouldn't mind getting a traction guide for a 350. Might have to try sniffing around LM. Your pic of a 4 car as me intrigued westcoaster.

 

[westcoaster]

My signature is just a 4 car 319, good ald trains will be a shame when they leave.