Electrical Advice

The relevant regulations are I think as follows:

BS 7671 513.1: cable joints must be accessible except where allowed by 526.3

which is covered by ...

BS 7671 526.3 (iv) joints made by welding, soldering, brazing or compression (which covers crimped connections)

So far so good. But:

526.5 (iii) Every termination and joint shall be in an enclosure partially formed or completed with non-combustible material.

This I think does not cover a choc box which is as far as I can make out is made...

 

So, I'm out on site the other day and the apprentice is installing some SY cable for a ring final circuit. Anyway, we got chatting and he mentions that this type of cable does not comply with BS7671! I said, "of course it does, it's part of the AM2 and it is one of the 7 cable types of the new 2357 apprenticeship NVQ! So out of curiosity I had a look. To my suprise, it does state in the BS7671, that this type, along with YY, CY are none compliant!! I know that most of this multi-core cable...

 

6 Way Metal Dual Split Consumer Unit c/w 2 RCDs (Type A) c/w 6 MCBs | BG (CFUDP16606A-01)

BG are stating that these are 18th edition compliant. I'm doubtful if they meet regulations 536.4.3.2 & 536.4.202 - overload protection of switches and RCCBs.

the RCDs are rated at 63A. There is no way of configuring the supplied MCBs that doesn't exceed 63A.

I guess if the main fuse was 60A it might be compliant but then would there not be an issue with the potential load of the...

 

Hello,

We have a mini split AC Inverter. We need electrical wire for the second mini split AC inverter.
Can we get a wire branch from the first AC terminal?
Do the voltage drop/sag and fluctuation occur?




...

 

I just want to check how I should be interpreting section 705.

705.411.1 states required disconnection devices, the first two indents covering final circuits and sockets, requiring 30ma and 100ma RCD's depending on rating of socket.
Indent 3 says " all other circuits" need 300ma RCD.

Does that include distribution circuits, outside? Or is the word "final" implied?

The background - a fused down main supply circuit runs along the drive of an estate. About half way along...

 

Hi,
I'm about to reroute cables and sockets/switches from the ceiling down to the socket height after insulating a wall.
I understand this will derate the cable, so what it the best way to do this please?

EDIT: Should be in DIY
Camerart

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Hi All,

Wondering if I can get some advice. Basically I’m having exposed joist ceilings in my house and I’m in the process of slowly changing all the cables over to new.

Currently I have 2 sockets within the lounge area chased into the brick plaster walls however I’m potentially looking to transfer over onto a stud wall. Basically the stud walls are insulated with space roll insulation which then had plasterboard sitting ontop.

Would it be possible to drop the cables behind the...

 

When altering / addition to an existing circuit and the RCD is a type AC but you notice DC components within that circuit do you upgrade the RCD to a type A? The original job would be just adding a socket outlet to the ring main

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All the specific guidance I can find stating that underfloor heating is notifiable seems to refer to an outdated version of Part P, and I’m trying to understand why generally everywhere still treats it as notifiable.
If a dedicated cable already exists from the consumer unit (so no new circuits are being created), the thermostat (and so connections) are outside of the bathroom as is always required, and the cabling is run under the floor (so is below the finished flood level) it doesn’t...

 

Hi,

I am currently reading through the standard IEC 61439-1 - Low-voltage swtichgear and controlgear assemblies - Part 1: General rules, and on Table 14 it is stated the "Relationship between prospective fault current and diameter of copper wire" (see picture attached).
I don't understand why the references of the copper wire diameter are so low. Based on this values you will have a very low cross sectional area of the wire. How come for example a 0,8 mm diameter copper wire can...

 

So I’m doing my level 3 design project at the moment, and I’m on the question where you do all the calculations on each circuit, I’ve taken the max earth impedance from the regs, but it’s asking me for the earth fault loop impedance of the circuit.

I think it’s asking me to calculate it, and I know the formula is Zs = Ze + R1 + R2 but I can only get the values for R1 + R2.

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Hi guys, I have a client who wants to install meters on every power circuit in order to monitor energy consumption etc. Just wondering if there is a specific method to wire up such a configuration on ring mains? As far as I can tell, I'd need to come out of the RCBO to the meter, and then have the two legs of my ring main leaving the meter. Would that not then classify the circuits as radials?

Thank you!

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Can someone explain electrically why we can spur unfused from a ring final on a 32a breaker when the cable is 2.5mm rated at max 27a?

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Given the RCD pictured below





With the manufacturers instructions here:



Am i right in interpreting that as well as being able to bring the incoming feeds into the bottom, i can also switch the LIVE and Neutral...

 

Does anyone know why water is leaking on that connection. Vaillant ecomax 824/2 E, It's heater exchanging connection, the one which is secured by the clamp (there is no rubber seal? -how does this even works ??) ...

 

Called out to look at a heating programmer (Honeywell 88608) that is reseting back to factory settings. Controls the hot water tank and a couple of towel radiators. Area has frequent power cuts and thought it could be a dead backup battery but replacing it didn't fix the issue. Replaced the 2 channel programmer with a different model (Sangamo CHPPR2) and noticed when setting it up that it reset back to factory settings when switching the heating load on. Checked all the wiring which is...

 

I've been away from electrical work for about 30 years so I'm not familiar with all the names and terminology that's been introduced over the years.

We're having UFH heating installed. Plumber is doing the pipework, s-plan etc and I'm installing a Heatmiser wiring centre. for the electrical side. Wiring everything up as per the attached diagram is pretty straightforward but I'm looking for confirmation where the boiler side connections go and looking for some help from those with...

 

Hi

I'm trying to figure out how to swap my standard myson thermostats for WiFi enabled ones - going to start with the simple one first - the one that doesn't control the hot water as well as heating - I've already got the touch 2 bridge installed and waiting for thermostats.

So I have two thermostats the one I'm starting with controls the upstairs temp - simple question with the two attached pictures how do I wire the one that has no wiring the same as the one you can see the wires in...

 

I have a question about wiring pump overrun on a Vaillant ecofit pure boiler (not a combi).

I had my old boiler replaced in 2019 and there was no provision for wiring the existing pump from the boiler in the existing wiring, and the fitter said it was OK to leave it so the pump switched on and off from the heat/hot water demand.

I’ve since read about pump overrun and that the boiler should have control of the pump for better heat management. Apparently Vaillant prefer this but they still...

 

Hi, picture attached. I have UFH on ground floor and 1st floor, each with their own manifold and their own control box for the actuators. By chance I discovered that there were two live feeds into these control boxes: on from the 3-pin plug that sits beside them, and the other feeding back into it from the boiler. This was not noticeable until a plumber pulled out the 3 pin plug, only to discover that the pins were live as the boiler live feed was flowing into them (I guess only when the...