RRI T24E Chassis

[19Seventy7]

Hi,

Just a quick question; about to test the 16.5v power rail, but is it safe to test the set as I do not have any form of safety equipment. I did try test without power but no surprises i didnt get a reading.

Thanks

[ms660]

Originally Posted by 19Seventy7

Hi,

Just a quick question; about to test the 16.5v power rail, but is it safe to test the set as I do not have any form of safety equipment. I did try test without power but no surprises i didnt get a reading.

Thanks

I would not work on that receiver when it's powered up unless it was powered via a mains safety isolating transformer of a suitable power rating, that's my take on it, others might have a different view.

Lawrence.

[19Seventy7]

That was my thoughts too. I've never touched anything inside while the set has power to it, so I didn't want to risk prodding around while it's powered.

What's a recommended power rating for a isolating transformer? I really should get one.

Thanks

[ms660]

Depends on the power consumption of the receiver, whatever it is it needs to be rated for at least that, I can't remember off hand what the typical power consumption is for a typical solid state colour TV is but someone on here will know, back in my TV servicing days some of the valve/hybrid colour TV's were very power hungry, the last place I worked at in the 1980's had a 500 watt job fitted to the bench if I remember correctly.

Lawrence.

[19Seventy7]

I'd be interested in doing some older stuff (50s/60s) but I'm not sure if it'd be any time soon.

Would 230V, 300vA be decent enough?

Thanks

[ms660]

It should be ok for the TV in question.

Lawrence.

[19Seventy7]

Okay thank you, i'll try get it.

Thanks

[Welsh Anorak]

Bear in mind an iso;ating transformer makes things safer, but not safe. So the old maxim of 'one hand in your pocket' still applies. The set you're working on has a mainly plastic chassis, so there aren't large metal areas unlike the old stuff.
The advantage of an isolating transformer is that the metalwork can be earthed so isn't floating, and touching, say, the tuner can won't hurt. My bench has a 500vA transformer which comes in handy for using test equipment on a 'half mains' chassis (a misnomer, I know). Of course, like everyone else I'd then go out and do house calls on a wet day in a house that was last rewired fifty years ago!
I'd never argue with anyone that puts his or her safety first - well, after mine, that is...

[toshiba tony]

Since the early days we were told isolation transformers should always be used, equipment is still lethal, I never carried one in my car but carried out repairs in the customers home when I could. There are still the same lethal voltages present, it's just that they are not at a potential to earth. An innocent looking mobile phone charger is just as dangerous as a widescreen tv, I'm amazed there are not more fatalities in this field, I know of two, please take this with a wry smile, an aerial rigger fell off the roof and the other wired his set the wrong way round, Thorn 8500, and grasped a central heating radiator and the tv chassis at the same time. But he was a know idiot in the community. (Yorkshire) One of my favourite good night greeting from the pub is "take care, we are all fragile", I'm now under care with dementia but luckily my near fifty years in the tv trade is still vivid, be good all, Tony Walker

[19Seventy7]

Sorry for the late reply.

I completely understand the dangers of working on electronics (Especially TVs) and should count myself lucky really that I haven't been hurt by them yet as I've absolutely no safety equipment. (I've had a few minor shocks, but nothing major)

I'll definitely be getting an isolation transformer to use from now on, and paused works on sets for now on.

Better safe than sorry.

Thanks

[Welsh Anorak]

As I said above, a transformer makes things safer, but not safe. All due precautions should still be employed. After all, 25kV is still 25kV, with or without a transformer!

[19Seventy7]

I completely understand, I've always been careful when I've got the back off one, and nothing will change!

Thanks