TiVo Power Supply - How safe?

[DazBarber]

Hi,

I had a horrible experience last week - my computer started to belch thick smoke. Luckily I was alerted by the fact that it rebooted as I was walking past the study and looked in to see why it had rebooted. Thankfully I intervened before it a) went up in flames or b) went bang.

I now have a new power supply and, luckily, all is well (although my temperatures are a bit high as my new PSU is a basic single fan model - I may have to get another) but this has got me thinking...

My TiVo is, in essence, a computer with, I imagine, a similar type of power supply. How safe is my TiVo (which is 5 years old this year)? As it is left running 24/7, if the same happened to its power supply while I was asleep or out, the consequences could be disastrous or potentially fatal!

I'm not trying to scare you all, I'm just rather anxious myself!

Any thoughts?

Daz

[cwaring]

Oh great. Something else to worry about to stop me getting to sleep at night. Thanks a lot ;):D

[pauljs]

If you have a smoke alarm then sleep tight :)

[TCM2007]

How many other devices in hour household are powered 24/7? Quuite a few I would think. I wouldn't worry about it. I've not had too many PCs catch fire either!

[terryeden]

Best thing to do is give all your devices a yearly dust bust. Get a few cans of compressed air (cheap at Costco) and blow away all the dust in the fans and vents of TiVo / PC / Projectors etc.

If you have the nerve (and the screwdrivers) open the equipment up and clean off the circuits with the air duster. Make sure the power is off :-)

Also, don't smoke near the equipment and hoover up pet hairs regularly.

T

[Pete77]

Not wishing to worry you further but Tivo power supplies appear to be notoriously unreliable and often do not last the life of the machine (unlike power supplies for most other electrical items) although normally they seem to die quietly without setting light to your home.

If you are really worried you can always buy and fit another one from www.tivoland.com. Its only £7 plus £4 delivery or something in their spares section.

[Tony Hoyle]

I have a small CO2 fire extinguisher away from any electrical devices just for this eventuallity.

I haven't had to use it yet, but if I do at least I'm prepared. They're only cheap and well worth having around.

[cwaring]

Not wishing to worry you further but Tivo power supplies appear to be notoriously unreliable and often do not last the life of the machine..
Well I'm still on the original one which came with my Tivo I purchased in 2002. Of course, you know what'll happen now, don't you :rolleyes: No matter. I have a couple of spares :D

[mikeyp]

surely it depends where you leave your tivo??? my tivo is on glass shelves under the tv, and only next to the other items which also are metal. There really isn't a lot of stuff to set fire to under there, so surely that provides a certain amount of protection against burning my house down. Also wouldn't the metal box of the tivo itself help contain any mishaps?

Couldn't this be applied to your computers once again? My PC isn't near anything it could set fire to, though I don't leave it on all the time...

also yes, smoke alarms highly recommended :P

[SteveA]

I've seen lots of computer power supplies go bang with sparks and smoke, but never had one cause a fire. The components and circuit boards are made of flame retardant materials.

On the other hand, I had a dishwasher catch fire after a slow water leak in the purge pump erroded the insulation on the motor coils. The loom connecting the motor glowed red hot, and all the pvc sleeving melted and caught alight.

The plug fuse didn't blow and the machine carried on with its programme while it burned!

Luckily I had a halon extinguisher on hand (before they were banned!) and managed to put the fire out.

The moral of this story is, I'm happy to leave a PC or TiVo powered up all night, but I would never start a dishwasher and go to bed!

[Pete77]

On the other hand, I had a dishwasher catch fire after a slow water leak in the purge pump erroded the insulation on the motor coils. The loom connecting the motor glowed red hot, and all the pvc sleeving melted and caught alight.

The plug fuse didn't blow and the machine carried on with its programme while it burned!

Luckily I had a halon extinguisher on hand (before they were banned!) and managed to put the fire out.

The moral of this story is, I'm happy to leave a PC or TiVo powered up all night, but I would never start a dishwasher and go to bed!

I often start the dishwasher and go to bed. You've got me worried now.

But what make was the dishwasher? I bet it was some crappy make like a Hotpoint or a Creda and not a nice make like a Miele or a Bosch/Neff/Siemens or even a Zanussi?

After I got a discontinued APC UPS cheaply from Staples after reading the instructions I did begin to wonder if I hadn't just purchased a 24/7 fire hazard and that risking the occasional power blips that we sometimes get here affecting the Tivo wasn't perhaps the lesser of the two evils.

[yungee]

Heh, I'm about to stick the dishwasher on and go to bed. If I don't post here for a few days, it's because my house burned down!

<fx: sound of fate being tempted> :D

[Pete77]

Heh, I'm about to stick the dishwasher on and go to bed. If I don't post here for a few days, it's because my house burned down!

Just make sure you have a couple of fire alarms that are working plus also a window lock key in your bedroom you can get at if you have any locks on the windows.

[AENG]

It used to be conventional wisdom that the sort of failures that caused fires were normally accompanied by an earth fault that a 30 mA sensitivity RCD would clear before real damage occurred. It would be instructive to know if any of you have found this to be untrue.

[SteveA]

Yes, well I have RCD spurs on the dishwasher and washing machine now! It was an Indesit, from the days when they were a private Italian company. Now we have a Zanussi- which has not caught fire (yet?) but has been very unreliable!

At least the Indesit worked flawlessly for many years, before it went out in style ;)

[Ian_m]

Yes, well I have RCD spurs on the dishwasher and washing machine now! It was an Indesit, from the days when they were a private Italian company. Now we have a Zanussi- which has not caught fire (yet?) but has been very unreliable!
The general wiring opinion now is to NOT put fixed kitchen appliances on RCDs (well individual RCD might be OK but as long as not on house RCD). This is to prevent false RCD trips from "wet" appliances tripping the whole house.

The definition of fixed is either wired to wall or 13A plug is not user accessable (ie behind unit). My kitchen fixed appliances (washing machine, dishwasher, fridge, freezer) are all on non RCD circuit where as the rest of the house is.

[Pete77]

The definition of fixed is either wired to wall or 13A plug is not user accessable (ie behind unit). My kitchen fixed appliances (washing machine, dishwasher, fridge, freezer) are all on non RCD circuit where as the rest of the house is.

My flat was wired in 1991 and has circuit breakers but no RCD cover I am aware of.

Is the fitting of RCD cover on circuits a more recent development?

[Ian_m]

If you have your house rewired today you will generally find the sockets will be on an RCD protected section. Basically if you have any possiblility of touching a live wire ie when removing a plug, a frayed cable then it should be on an RCD.

Thus you don't need to place fixed appliances boilers, heaters, cookers etc on an RCD as in normal use you should not be able to access the live conductor. The fault of live connecting to case is covered as this will be earthed and the overcurrent will trip the breaker/fuse. The skill in design is ensuring the earth is big enough to cause sufficient overcurrent to trip the breaker/fuse quickly so that anyone touching it does not get a serious shock, the higher the current the quicker the breaker/fuse disconnects.

The RCD detects the difference between the live current and neutral current and if greater than 30mA ie as its going to earth or through something else, it cuts the power.

Generally now as well the whole house will be protected with an 100mA RCD device which has the potential to kill before tripping but is designed to trip if there is a more serious house fault.

See here for a modern consumer unit (ok hasn't got 100mA RCD, but usual to change that).
http://www.tlc-direct.co.uk/Products/HGVECOS66slash6H.html

You connect you fixed appliances, cookers, showers, lights to one of the split sides and house sockets to the 30mA protected side.

Remember RCD protects a person and breaker (MCB)/fuse protects the wiring.

TLC also have some of the latest wiring regs here as well.
http://www.tlc-direct.co.uk/Book/1.1.htm

Oh and as a fly in the oinment, some/most computer rooms are non RCD a PC/computers do leak to earth (maybe 1ma) thus a lot of computers can cause false RCD trips. So either loads of individual RCD's or non at all is quite common.

[SteveA]

The general wiring opinion now is to NOT put fixed kitchen appliances on RCDs (well individual RCD might be OK but as long as not on house RCD). This is to prevent false RCD trips from "wet" appliances tripping the whole house.

The definition of fixed is either wired to wall or 13A plug is not user accessable (ie behind unit). My kitchen fixed appliances (washing machine, dishwasher, fridge, freezer) are all on non RCD circuit where as the rest of the house is.

That's why they're on spurs- there is no "over all" RCD. They are standard 30mA RCDs and neither has tripped in 10 years (and I do test them!)

I think the law now requires drinks vending machines to be protected by RCDs, and I would consider them "wet" appliances!

I've also got outdoor wiring protected by an RCD, which includes a submerged fountain pump. I don't have problems with trips - they day I do, I will replace the offending items.

[Ian_m]

I've also got outdoor wiring protected by an RCD, which includes a submerged fountain pump. I don't have problems with trips - they day I do, I will replace the offending items.
The only false RCD tripping I have ever seen were an old washing machine that always tripped at start of spin cycle and very old fridge. I ran our new fridge and freezer on RCD circuit (until kitchen was redone) on RCD ring for about a year with no trips.

The last couple of trips on my house were me overwatering my wifes iron and touching the neutral and earth (live was isolated, breaker removed) whilst wiring in the kicthen.

[iankb]

I wouldn't rely on an RCD to catch motors burning out. I've blown two electric motor mowers that were connected to RCD's. Both emitted a suitable amount of smoke before they packed in, but neither actually tripped the (two different) RCD's.

Since changed from Flymo's to Bosch - much better motors, and much better at handling long wet grass. :)

[SteveA]

Well, its not reliance, so much as an extra layer of protection! If there's no nuisance from false trips, it might as well be there...

[Ian_m]

I wouldn't rely on an RCD to catch motors burning out. I've blown two electric motor mowers that were connected to RCD's. Both emitted a suitable amount of smoke before they packed in, but neither actually tripped the (two different) RCD's.When I mowed through the cable (why is it always bang in the middle rather than near one end so easier to fix???) I got a shower of sparks as it blew the edge of the mower blade, but did not trip the RCD or 32A breaker.

I assume the surge was too short (or not big enough) to trigger the breaker and as the mower was double insulated (no earth) the cut was live to neutral so not triggering the RCD. Its interesting that when you do this type of thing how there is a great urge to go and pick the end of the cable up and have a look....damp cable, damp person outside, 240V....thats why RCD's are useful.

Anyway tested RCD by its test switch and my RCD test box (2 resistors live to ground if I remember right) and all OK so probably just a complete fluke why nothing tripped.