Class 390 bogies

[EFielding32]

Hello all,
Bit of an unusual one here, I’ve frequently noticed these attachments on pendolino bogies - always on the pantograph carriage…does anyone happen to know what purpose they serve ?
Photos attached below.

 

[Jammy Dodger]

Random theory - mounting point for a 3rd rail shoe?

 

[swt_passenger]

I believe it’s the train sensor that reads the magnet to open the main circuit breaker on approach to a neutral section. Automatic Power Control (APC) magnet.

 

[DanNCL]

I believe it’s the train sensor that reads the magnet to open the main circuit breaker on approach to a neutral section. Automatic Power Control (APC) magnet.

And also to close the main circuit breaker at the second APC magnet after the neutral section.

 

[swt_passenger]

And also to close the main circuit breaker at the second APC magnet after the neutral section.

Of course - kept it simple!

 

[EFielding32]

Ace, thanks guys !

 

[Minicheddar]

Hello all,
Bit of an unusual one here, I’ve frequently noticed these attachments on pendolino bogies - always on the pantograph carriage…does anyone happen to know what purpose they serve ?
Photos attached below.

That's the automatic power control magnet, there's one fitted to all trains that are powered by the 25kv OLE system, when the train goes through a neutral section it passes over a magnet placed next to the track and opens the VCB (Vacuum circuit breaker). This is a major component in protecting the train from electrical damage and essentially breaks the connection from then pantograph to the train, a second magnet a few meters down from the first the closes the VCB and allows power back to the train.

 

[Elecman]

APC (Automatic Power Control) magnet receiver to operate the 25kV main breaker either side of a Neutral Section

 

[Nym]

That's the automatic power control magnet, there's one fitted to all trains that are powered by the 25kv OLE system, when the train goes through a neutral section it passes over a magnet placed next to the track and opens the VCB (Vacuum circuit breaker). This is a major component in protecting the train from electrical damage and essentially breaks the connection from then pantograph to the train, a second magnet a few meters down from the first the closes the VCB and allows power back to the train.

All modern 25kV units and locomotives...(!)

(Also MENTOR, but they're more complicated on there).

 

[Snow1964]

These days they just open and close the circuit breakers, but up until about 1983 (40 years ago) there was a second detection for voltage.

There were areas that were 6.25kv where clearances were less, or had been converted from 1.5kv dc and were still using the smaller insulators. The last of these were fully converted to 25kv and trains that still had the equipment subsequently had it isolated or removed.

For info, After circuit breaker triggered and train in neutral section, the voltage detector switched a series or parallel transformer winding (4 windings would be connected as one series to reduce 4 times the voltage, or in parallel for the lower quarter voltage), this switching had to happen before passed the circuit breaker opening at end of neutral section.

 

[XAM2175]

All modern 25kV units and locomotives...(!)

They are especially noticeable on 390s, it must be said.

Random theory - mounting point for a 3rd rail shoe?

Sometimes it's better not to guess