Recent content by WellKnownSid

Usually nothing more complicated than an R/C circuit - possibly a capacitor to clamp the gate of the SCR, depending on the chip doing the processing. A couple of decades ago I had a sideline designing some of the electronics for a well-known brand of RCD. IIRC the Raytheon RV4141 chip that...

There are usually one or two components inside an RCD which help prevent nuisance tripping - these can sometimes fail (or they forget to fit them on the production line :roll:) which results in the fault you describe... However... RCD tolerances are quite wide - it's theoretically possible...

Quick update... Took the cover off the cutout this morning - definitely CNE (before Westie has a heart attack... this is Scotland, and the electrician had already agreed that the seals could be removed) On closer inspection, the pole does have two earth conductors - one which forms the...

Aside from not having a voltage reference, these are measuring current using a mass-produced solid state sensor built for cost not accuracy. The major issue is that they are very non-linear for the first couple of hundred watts. For example, we have a timer that uses about 3W (measured) that...

That was always my understanding of TN-C-S (PME) - however that's based on me once being an electrical engineer a couple of decades ago, and then spending more time on HV than LV. The mists are clearing... The state of the cutout suggests that the LV supply was all renewed when it became...

Definitely a plastic pipe... Okay, okay, I'm new to this electrickery lark... The main protective bonding conductor cross sectional areas did not meet the minimum requirements of table 54.8...

That much has been sussed already. On the face of it, the electrics looked really solid. It was originally two houses - before they mysteriously burnt to the ground (presumably in some earth-related electrical fault :roll:) about 30 years ago. So - early 1980s build - CPC in all the...

Yep, I think the Hydro boys will be the only ones who can answer this one... We'll give them a ring and keep you posted...

At the transformer, either via a rogue cow / tractor / or 'person known to travel'. The supply disappears underground (straight concentric) and re-appears at the house with no additional earthing point in between or at the house end. My understanding of PME was that there was an M in it...

Yes, wrapped around a plastic pipe and clearly pointless... What about a loss of the (single, unprotected) source earth?

We have a property we're renovating and is currently being re-wired. TN-C-S supply - but there is only a single connection to earth at the pole top TX itself which is 50 feet from the the house. Given that the mains water service is plastic (despite this, it has been cunningly bonded to a...

A neighbour of mine once claimed to have rewired his house entirely in MI, all courtesy of the London Underground... :shock:

Many years ago I knew an electrician for one of the fire contractors employed by the underground. He rewired his entire house in red sleeved MICC. I never asked... Serious question... how hard IS pyro? I can see the attraction for outbuildings... fit and forget.

Thanks all, really useful info. I suppose my caution over eBay is stuff like this :shock: http://www.ebay.co.uk/itm/Multi-Function-Tester-Screwdriver-Check-AC-Voltage-Fuses-Break-Point-Appliances-/130778713291?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item1e7304cccb £350 -...

I'm looking for a basic MFT or test kits that'll cover the 17th edition tests for a single phase domestic supply. Don't fancy the hassle of buying second hand and sending off for recalibration. Don't need PC interfaces, bluetooth or rechargeable batteries, just something that'll happily sit...