Help! Electrical shocker!
Posted by: Mike Dudley on 12 March 2009
I'm a bit of an ignoramus when it comes to the physics of electricity, so can any of the Illuminati here present reassure me? The protection switch on my spur feed just cut out and the whole stack went dead. I've switched it back on and everything seems fine now, but I have noticed that the XPS seems to be running warm. Am I right in thinking this cutout could only be due to a supply surge, or is there some weird feedback malfunction from the stack that could cause it?
Posted on: 12 March 2009 by ianrobertm
OK. Should not be difficult. (Trust me - I'm an Engineer!!!)
What is the rating of the Protection Switch you mention.. in Amps..?
What does your 'stack' consist of..which Naim units..?
Of course, if you have any doubt - switch it ALL off. Safety First.
Posted on: 12 March 2009 by Mike Dudley
Thanks Ian.
45 amp.
Stack is CDX (black)/XPS (olive)/NAC202 with NAPSC/NAP200/NACA5 to ProAc D15's all on an Isoblue rack.
Posted on: 12 March 2009 by ianrobertm
After a short interuption...
As far as I know, Surrey is 230V AC. So, according to the laws of Electrikery, to trip a 45 Amp Circuit Breaker you have managed to pull 10350 Watts. Which is a lot. Just over 10 kW - or 5 electric fires worth.
There is no way that is 'Normal'. It WAY over what your Naim's would pull.
I assume none of the Naim rear panel fuses have blown - or 1 of the boxes wouldn't be working..? Naim's fuses are what really protects the units, I believe.
So, my 'best guess' is that your 45A CB was tripped by external forces. Such a transient induced on your mains. (anything odd going on, near by..?)
Alternatively, your 45A CB might be faulty... I assume it hasn't done this before.?
Posted on: 12 March 2009 by 555
Here comes Adam ...
Posted on: 12 March 2009 by DaveBk
You mention 'Protection Switch' - is this an MCB or an RCD? MCB's provide over current protection and as stated earlier they need alot of current to trip, but RCD's are very sensitive. They detect leakage to earth and only need 30mA to trip - sometimes just a brief disturbance in the mains can trip them.
Posted on: 12 March 2009 by 555
quote:
Melbourne?
Meredith
Posted on: 12 March 2009 by Mike Dudley
Well, there've been no UFO's outside or any sightings of "Energy Man" sticking his fingers in the street mains, so I guess it must be an "RCD"... Hasn't happened again since, so I guess I'm all right. Thanks for all your responses and thanks for the reassurance, DaveBK. It's been a long project, getting this system together, needing a lot of patience - now I just need to wait for a month for the new PCB in the preamp to wear in and I'm there.
Posted on: 13 March 2009 by Naim User - Graeme
Hi Mike
We had a problem in Spain with the protection for the whole house tripping out. Very worrying. Then I noticed that it was always at a specific times. We had nothing switching on or off in the house at these times.
I monitored the mains voltage. Within a few seconds of these times, it jumped around all over the place. Our neighbours had also noticed strange things. The conclusion was that industrial units near us were powering up at the beginning of a day (about 8:15am and off at 9pm.)
There is some info re nuisance tripping here but it is dated 2001.
http://www.westernautomation.com/pages/demystify.htm#problemsWe explained to the electrician who installed all the electrics to our new estate; he checked our house and found nothing wrong. All of a sudden, after a few weeks, the problem stopped.
I hope your problem does not happen again; if it does, I suggest making a log of the time, what you had switched on and get a electrician to check out you circuits.
Graeme
Posted on: 13 March 2009 by John M
quote:
Originally posted by avole:
Melbourne?
sandstorm in Riyadh I think
