digital projector: grounding necessary?

[VJ]

Hello,

Quick question: is it necessary for a digital projector (using XSRD or LCOS technology) to be grounded for it to operate properly?
The manual clearly states it must be earthed ... but I don't know if the manufacturer states this out of general precaution or out of necessity...

I want to install a projector, but just realized that I have no grounded sockets in that room (only in the kitchen and bathroom).
Any options (the place is a rental apartment, so I can't start rewiring)?

Thanks!


Jörg

[Dr Mordrid]

Dunno about Europe but here in the US using 120 vac the ground is somewhat redundant, though required by code, since the neutral (white wire) is grounded at the breaker box.

[VJ]

I'm currently renting an apartment in a 1970s building in Warsaw, and just realized this. The electricity is quite primitive: the fuse box actually has 2 round fuses for the whole of the apartment . If necessary, I might be able to run an extension cord from a grounded socket in the kitchen, but it wouldn't be vey elegant...

For some devices, the ground is a necessity (e.g. record players), for others it is more of a safety measure. With computers, it puzzles me somewhat that desktops are grounded, but laptops rarely are. I wonder in what category the projector is.

[degrub]

In the US, if it is a 3 wire device - hot, neutral, safety gnd then if you plug it into a 2 wire outlet and there is an electrical fault to the case and you touch the case providing a path to earth, you will get a shock - possibly fatal because of the high current.

If it is a 2 wire device, then in the US it will be "double insulated" and it should not be easily possible to have a fault to the case.

Don't know the codes in Europe, but the safe choice is plug into what matches exactly.

With a projector, you could have some very high voltages internally supplying the lamp. That is likely the reason for the safety gnd requirement, not providing a reference gnd.

With laptops, all of the internal voltages are small and generally DC. The only dangerous portion is the battery charger and that is usually double insulated, but not always.

[gt40]

Besides the safety issues: typically, the built in surge protectors on computers/digital equipment are ground referenced. Using it in an ungrounded outlet leaves it susceptible to damage.
Can you not find an electrician to install a proper outlet?

[Tjalfe]

In the US, if it is a 3 wire device - hot, neutral, safety gnd then if you plug it into a 2 wire outlet and there is an electrical fault to the case and you touch the case providing a path to earth, you will get a shock - possibly fatal because of the high current.

Luckily the breaker being 15+ amps has nothing to do with how fatal the shock is here. Ohms law makes the higher voltage in Europe more dangerous in that respect

[VJ]

I'm not sure the wiring is present for it... I have one socket which is hanging from the wall, and there I can see that the cable going into the socket only has 2 cables (black and blue). In the hole in the wall, I can see another black cable, but also a red cable, but they just seem to run through there (there is no branch or bare connector or anything like that). Also from the looks of things, rewiring would seem impossible: cables are fixed in the walls (no apparent cable gutters as one would expect).

The room does not share a wall with bathroom or kitchen, otherwise it might have been possible to get a socket from the other side of the wall (a friend of mine did this in an old appartment, to get a grounded socket for his computer).


Jörg

[degrub]

Since the breaker is intended to protect the wiring, it will pass more than enough current in the fraction of a second it takes to heat up and open. The breaker will not necessarily protect you. Same for a fuse.

Sounds like it is time for an electrician. Perhaps the owner would be open to the expense ?, Otherwise, if you can get your hands on a simple plug in 3 wire tester ( any home supply shop has them here in the US, maybe in Poland also ?) from a friend, i would verify the other grounded plugs are truly that. i have seen many old properties that had 3 wire receptacles that were not connected properly - if at all, to a safety ground.

[VJ]

I finally got round to continuing this (after all the shipping-misery - which hasn't been solved yet).
I openend one of the sockets in the kitchen that have a grounding pin, and... it is not connected. Looked at some other similar sockets, and it is the same all over the place: there simply is no grounding wire to be found anywhere. It makes me wonder if even rewiring the place will make it possible to ground it properly, but it is a moot point as I pretty sure the owner will not be up for it. The electricity is very primitive (I basically have 2 antique screw-in circuitbreakers for the whole apartment: 10A and 15A), especially when compared to the requirements in Belgium (each room needs to have at least two seperate circuits with automatic breakers for light fixtures and sockets, and then some machines also must be on their own circuit).

So I'll have to make do with what I got... As the Sony projector I was looking at has it as "mandatory", and in big warning letters on the manual, I'm guessing it is more than just merely a safety precaution and may be related to the inner workings of the SXRD/LCOS technology. I browsed manuals for other projectors, and did found some that make no mention whatsoever of grounding the device (it was either Sanyo or Epson, definately one using 3LCD technology).

I'm guessing now the most easy thing is to just settle for one of those...?
Any other suggestions/thoughts?

Thanks!

[Chucky Cheese]

Grounding

How about the buildings ground? can you intercept that ground with a solid core wire and get it up the side of the building and into your apt?

[VJ]

I'm on the 4th floor (but it is higher than it sounds: the celings are 3m heigh), and the grond below me is a sidewalk on one side and a lower building on the other. I doubt that is in an option...

[Chucky Cheese]

Options

I was thinking more on the lines of maybe some utility closet or appliance closet. Does each floor have a "common" place where the utilities are fed onto each floor? Also what about a "cold" ground, and that is nothing more than attaching a wire(..clamp or solder) to the cold water feed to your place(..as long as it is copper).

[VJ]

Nope... Each apartment has a small cabinet outside that only has the water counters (hot/cold) and main taps for the apartment. Some TV cables are running bare near the ceiling, but that is it... Don't forget it was built in the 1960s in what was then eastern Europe...

The cold water taps in the walls in the apartment are inox with flexible tubing attached. I assume a painted cast-iron radiator will not suffice?

[Chucky Cheese]

Cast Iron

Not sure about cast iron...if you measure between the cast iron(...scraping off the paint of course) and the supply line(...220 volt?) with a DVOM what reading do you get?

[VJ]

I don't have a DVOM, but just now also considered that if the device actually needs a functional earth, it may not be a good idea to put it on something people can touch (or connect with other things...)...