Plug sockets on Trains

[Train Maniac]

Curious, What is the actual reasoning behind the plug sockets by the doors on modern stock (specifically electrostar units) marked as 'Not for public use'. Seems a bit silly when there are no other rechargeable plug sockets elsewhere on the train?

 

[SuperLuke2334]

Curious, What is the actual reasoning behind the plug sockets by the doors on modern stock (specifically electrostar units) marked as 'Not for public use'. Seems a bit silly when there are no other rechargeable plug sockets elsewhere on the train?

Used for cleaners etc I believe to power their vacuum cleaners and the like.

 

[JonathanH]

What is the actual reasoning behind the plug sockets by the doors on modern stock (specifically electrostar units) marked as 'Not for public use'.

The usual explanation is that they may provide variable voltage while out on the network which will fry your equipment, but can provide reliable voltage in a depot for cleaning.

 

[skyhigh]

The usual explanation is that they may provide variable voltage while out on the network which will fry your equipment, but can provide reliable voltage in a depot for cleaning.

And also partly because using plug sockets next to the doors is a recipe for a trip hazard.

 

[SouthernR]

I'm not familiar with railway regulations, but I would have expected vacuum cleaners to be 110V.
As for charging sockets, what are these circuits commonly rated at? Is there any protection to prevent the supply of higher loads, such as heaters or vacuum cleaners (say 5-13 A)?

 

[507020]

I noticed a plug socket on an unrefurbished Class 319 unit at Lime Street recently and wondered why it was the only one when they are now so common on trains for passenger use.

On aircraft I have noticed US/Japan spec 2 pin NEMA plugs with a label stating 110V 400Hz for vacuum use only, which of course is deliberately incompatible with consumer equipment but a standard voltage for aircraft cleaning.

But BS1363 requires 240V (no, not 230V, it never has been) so you can not have a BS1363 3 pin plug which does not deliver a standard voltage. Even the most primitive 100:1 reduction step down transformer would be able to deliver 250V 50Hz directly from the overhead line (although this would be more complex to provide from the 3rd rail with massive variation in DC voltage) which should be compatible for most purposes.

 

[Energy]

I'm not familiar with railway regulations, but I would have expected vacuum cleaners to be 110V.

Why? AFAIK its 230v, otherwise they'd put a special 110v plug on the cleaning sockets.

As for charging sockets, what are these circuits commonly rated at? Is there any protection to prevent the supply of higher loads, such as heaters or vacuum cleaners (say 5-13 A)?

There is the breaker for all the plugs in a carriage. How much it can take will vary, typically train which have had plug sockets retrofitted will have it smaller due to limited ETS capacity.

The usual explanation is that they may provide variable voltage while out on the network which will fry your equipment, but can provide reliable voltage in a depot for cleaning.

Also that the ETS supply is assuming a load of not a lot (>3A would be enough for a vacuum cleaner).

 

[dk1]

Was just for internal use such as cleaners/maintenance staff. As mobile technology became more prolific some notices were put nearby informing the public that their equipment could be damaged so do not use. I know many guards who advised passengers that they are free to use them but at their own risk as any surge will more likely find you regretting plugging it in.

 

[Train Maniac]

Was just for internal use such as cleaners/maintenance staff. As mobile technology became more prolific some notices were put nearby informing the public that their equipment could be damaged so do not use. I know many guards who advised passengers that they are free to use them but at their own risk as any surge will more likely find you regretting plugging it in.

Yeah ive been told the same before. No ill has come of it yet

 

[SouthernR]

Why? AFAIK its 230v, otherwise they'd put a special 110v plug on the cleaning sockets.

There is the breaker for all the plugs in a carriage. How much it can take will vary, typically train which have had plug sockets retrofitted will have it smaller due to limited ETS capacity.

Also that the ETS supply is assuming a load of not a lot (>3A would be enough for a vacuum cleaner).

230V tools are not permitted on construction sites, for example. I didn't know if railway depots were similar.
Industrial 110V plugs and sockets are different, rather than special.

I wondered whether any measures were taken to restrict the current (<13A) at the charging sockets. Clearly not, if all the sockets in a carriage are fed from a single breaker.

 

[Energy]

230V tools are not permitted on construction sites, for example. I didn't know if railway depots were similar.
Industrial 110V plugs and sockets are different, rather than special.

110v is split into 55V and -55V on construction sites as a human can survive a shock at 55v a lot better than 230v. The cleaner sockets on trains are permanent installations.

I wondered whether any measures were taken to restrict the current (<13A) at the charging sockets. Clearly not, if all the sockets in a carriage are fed from a single breaker.

I'm not sure tbh, installation will vary train to train.

 

[Clarence Yard]

Train Maintenance Depots are not classed as construction sites. 230v is the standard voltage for light equipment, such as vacuum cleaners, used on depots.

 

[king_walnut]

The usual explanation is that they may provide variable voltage while out on the network which will fry your equipment, but can provide reliable voltage in a depot for cleaning.

There is no issue with using these plugs to power domestic goods such as mobile phones and laptops. The voltage is fine and comes from a source that supplies much more sensitive train control equipment than phones and laptops. Each plug is protected from surge by a circuit breaker and that is tested once a week.

 

[dosxuk]

BS1363 requires 240V (no, not 230V, it never has been)

BS1363 is a standard for plugs and sockets, it doesn't specify the voltage output by the sockets.

The UK standard mains voltage is 230V -6% +10% and has been for many years after harmonisation across Europe. Voltages between 216V and 253V are within specification. BS1363 plugs and sockets are approved for 250V use and below (although this number is derived from the requirements in BS EN 60664-1 and the nominal supply voltage, so they should probably actually be marked as 253.6V rather than 250V).


If these cleaners sockets are live and accessible to the public, even with a sign saying "not for public use", they should conform to the standard electricity supply specifications - especially over/under voltage, frequency and stability. A simple sticker is not a sufficient control measure if the supply would be dangerous to use with domestic equipment - alternative means of control, such as isolation when not in a depot - would need to be employed. However, it the supply is safe to use, but unpredictable - e.g. turning on/off through neutral sections; or extremely low current capability such that it would trip out if common equipment was connected, then a simple sign is sufficient.

If a connection that is only accessible to authorised users was required, there are alternative connectors available that most people don't have access to (such as the T-shaped earth pins, commonly found in hospitals), or the connectors could be installed behind a lockable panel.

 

[Elecman]

110v is split into 55V and -55V on construction sites as a human can survive a shock at 55v a lot better than 230v.

Technically it’s 55v-0-55v centre tapped to Earth to give 110 volts but restricted to 55 volts with reference to Earth