What Will Work using those On-Train Sockets ?

[Kingfisher200262]

On vehicles with modern passenger socket installations (so, either new trains or refurbs where sockets are added), there's usually an inverter to provide "clean" 240 V ac, and it's usually sized to be able to accommodate all the sockets used at the same time, with a 100 W load (i.e. a laptop and a bit more). The wiring and the sockets themselves are rated much higher.

So, on a vehicle with say 32 sockets (randomish number), the maximum expected load will be 3.2 kW (c. 13 amps @ 240 V ac). It therefore follows that when very few sockets are in use, someone could probably plug in pretty much anything domestic and nothing bad would happen.

The worst that could ever happen is that the circuit breaker on output side of the inverter would trip, or the thermal overload on the inverter itself trips.

 

[Flamingo]

I was told different when I was training, but I'll ask a fitter next time I see one. The at-seat plugs on the hst's have been introduced since I trained.

I don't think they are surge protected, as they are intended to be used by cleaners when the train is stabled to a shore supply / engine at idle, not when powering up/down. That might have changed, again, next time I see a fitter I'll ask.

I spoke to a fitter yesterday who said the plugs in the luggage racks on HST's are 220V.

 

[brianthegiant]

My experience is different.
There have been a considerable number of IEC mains leads (often, and wrongly, called 'kettle leads') found which have non conducting earth pins and consequently fail a PAT test. These are commonly used to power portable and installed IT equipment and depending on the application can present a considerable hazard.

Well, maybe, but where is the hazard in loss of CPC to a plastic cased class II switch mode power supply?

 

[185]

A certain well known trolley steward brought my train to a halt by plugging the trolley urn into the socket.

*BANG!*

Transpennine's longest serving steward of over 30 years, too. :roll:

 

[Eagle]

I did once overhear someone on a train say something about there being so many laptops plugged in in this carriage it might "blow the pantograph" (actually, I think the exact term they used was "overhead collector thingy"). This was on a Voyager...

 

[Kingfisher200262]

I did once overhear someone on a train say something about there being so many laptops plugged in in this carriage it might "blow the pantograph" (actually, I think the exact term they used was "overhead collector thingy"). This was on a Voyager...

Ignorance is bliss. :roll:

 

[DaveNewcastle]

Well, maybe, but where is the hazard in loss of CPC to a plastic cased class II switch mode power supply?

These IEC leads without an Earth MUST be treated as a failures; who is to know what they may be connected to and whether it has exposed metal parts or not? They are a hazard.


On the HST coaches I'm familiar with, the inverter for the sockets is in each coach behind two seat-backs (and with a very large heatsink!).

 

[ryan125hst]

On the HST coaches I'm familiar with, the inverter for the sockets is in each coach behind two seat-backs (and with a very large heatsink!).

Why do HST carriages need inverters? The power cars supply 415v three phase ETS. Can't 230v single phase be taken from that? Or are inverters used to make the power supply more stable? If this is the case, what voltage does it take in- DC from the batteries (at whatever voltage the batteries under each coach are) or does it rectify 230v from the train supply and invert it to 230v AC again to ensure that the supply is stable?

 

[Kingfisher200262]

Why do HST carriages need inverters? The power cars supply 415v three phase ETS. Can't 230v single phase be taken from that? Or are inverters used to make the power supply more stable? If this is the case, what voltage does it take in- DC from the batteries (at whatever voltage the batteries under each coach are) or does it rectify 230v from the train supply and invert it to 230v AC again to ensure that the supply is stable?

Each operator's fleet may be different (the joys of privatisation :roll, but in general, there are two reasons why the laptop sockets should be fed from the batteries, through an inverter. Firstly, the 415 V ac from the power car is notoriously dirty, because it's a straight feed from the auxiliary alternator that is on the end of the engine. Secondly, feeding the sockets from the batteries, means that the sockets still work, when the power car that provides electric train supply is not running.