ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades U.K. Pics: Main distribution panels

Paul,
Sorry, but I never had a close read of your comments in your above post.
Am I assuming that a system of different boards for different Rates applies, in the UK?.
I see that the Consumer unit above the Service Fuse has a large cable exitting it, would this be for a Shower?.
Over here, we would normally supply a Night-store heater or Hot water cylinder from the same board, but it is normally fed from the Meterboard(outside, usually) via the Ripple Relay+ Pilot Wire.
As a rule, an MCB, is fitted to the left side of the Main Switch or a Multi- DIN Rail Board is fitted and all of the Night Rate equipment has it's own Rail.
This just keeps everything tidy and makes Fault-finding easier.

I've never known the little plugs on the fuse carriers as anything other than a way to cover up the live fixing bolts and identify the fuse carrier rating (in the picture above, white=5A).

Yes, on many installations it's quite normal to have a separate distribution panel for the nigh storage heaters. In the photo above, power from the service fuse and neutral block goes straight into the meter. You can also see some smaller cables from the blocks which feed power to the radio-teleswitch, purely for its control side (via the fuse which is located below the meter). The thin cable running from the switch to the meter is the control line causes a solenoid in the meter to mechanically transfer the drive from the normal-rate dials to the night-rate dials.

From the meter, the cables go into the bottom of the main RCD, and from there into the large black junction box at the upper right of the picture. Two pairs of cables go straight from that box to the main panel and the smaller additional panel. (And yes, the cable emerging from that panel did go to a shower, as I recall.)

From the junction box, there is also a neutral taken directly to the night-heater panel, but the live side is run via the contactor terminals on the radio-teleswitch.

It's not too clear in the photo, but if you look to the right of the main unit, behind the cables going into the black junction box, you might just be able to make out that there's an earthing block there linking the earth on the panels and providing bonding and connection to the local ground rod. (This is a TT installation, so there's no earth-neutral bond at the house.)

This is a typical arrangement which applies power for heating only at night, but which also switches the meter so that everything in the house benefits from the low night rate.

There were older schemes which had a second meter fitted and a timeclock to feed the heating panel. It was only the heaters which benefited from the cheap rate, as the main panel remained on the standard-tariff meter all the time. Many people still talk about "white meter" rates, as this was the color of the low-rate meter used on these dual-meter setups.

New installations with DIN-rail mounted breakers can indeed use a split bus arrangement and put the night-heater circuits in the same panel.

Paul,

That's completely unlike anything used here for night rate heating "NightSaver".

Over here on very old installations you'd have 2 seperate meters with the heaters connected to the night rate one via a big electromechanical timer that flips them on at midnight. Each heater would be on it's own 16 / 20 amp diazed fuse on a seperate panel. (If the heating system was sufficiently large it was a seperate 63 amp supply)

(The really old timers were quite noisy, ticked all the time.. but were always located in a garage or in the meter cabinate )

On newer installations a split bus would be used on the night rate heaters including a DIN rail mounted timer arrangement. Each heater would have appropriate radial MCB (16/20 amp).

The meter either includes an electromechanical timer that trips it to the night rate dial or else is fully digital and just automatically goes into night mode after midnight. in this case the whole house gets night rate not just the heaters.

In the newer setup's the water heating system would also be timed (seperately) to power up and heat over night. In older systems they would have gone as far as having a day and night immerision element in one tank! (It was cheaper than interlocks and timers)

The dual-meter system with a mechanical timeclock sounds very much like the old white-meter system that was used here. I don't think any PoCo still offers it as an option, but there might be a few still in use somewhere.

The storage heaters here also use individual radial circuits, one per heater, rated 15/16 or 20A.

Water heating arrangments vary somewhat. In setups such as the one pictured above and where there is only a single element, it's quite common to install an individual timer for the immersion heater which can be adjusted by the homeowner as required, and also allows for manual boost during the day.

Dual-element systems used to be quite popular, sometimes with the main (lower) element wired to the night meter circuits and the smaller (upper) element on a manual switch with power available all day.

A common sight at one time was a twin switch, one marked ON/OFF and the other SINK/BATH, which transferred power between the upper and lower elements.

While we're on the subject of water cylinders and immersion heaters, the cupboard into which the cylinder is built here is generally called an airing cupboard.

I noticed that in Ireland you seem to use the term hot press. Any idea how this originated?

Pretty simple really:

Press = cupboard over here. (Kitchen cabinates are usually called presses)

and in the case of an airing cupboard it's hot inside.. hence it's a "hot press"

They are around quite a while, pre-dating electrically heated immersion heaters, old ranges often heated water cylinders that would have been located in a "hotpress" in the kitchen.

Also, our wiring regs have pushed away from mounting the controls in the cupboard itself, due to a risk of over heating, they are now supposed to be flush mounted on the wall outside.

We never had a white meter we just had 2 big massive black siemens meters and a timer that was almost the same size, also siemens, sitting in the middle.. (all sealed by the ESB). The distribution board (consumer unit) would have been much bigger though. Big old diazed unit with maybe 10 fuses.

At least DIN rails & electronnics etc have made things a little neater

The system was and still is called "NightSaver" and had a terribly corny song to advertise it... something along the lines of "sparkling clean dishes and clean dry clothes, night saver's the answer and here's how it goes.." (shudder)

There are also "GoldShield homes". This is an ESB programme to build homes with integrated electric heating (storage for background, local boost heating, under-floor heating, electric showers, electric water heating (often done in a super-insulated tank more like those found in other EU countries than in the UK) and extremely high levels of insulation. The larger homes are sometimes supplied with 380V power for the heating systems.

It was popular but it's not as flexible as gas fired radiator systems and I don't think the ESB is currently encouraging people to opt to use vast amounts of power, at least until the network capacity catches up with the recent explosion in consumption.

I hope you didnt connect that consumer unit Paul,,,,,,,, rather untidy..

you will be giving them bad ideas on how we do things over here in the UK

Nope, not my work! That's just how it was when I arrived.

DJK,
Thanks for that. I didn't realize that press=cupboard. Hot press makes perfect sense now I know that!