Is this installation considered acceptable today? (1-ring including oven and everything else)

[Iain Kay]

In my view that is commercial scale use of a domestic supply "technicalities" aside, to put it another way it is not normal domestic use of a system designed for exclusively domestic use. If I were a landlord and the system was overloaded by your use I would be looking to you for reparations. The onus would be on you to rebutt the claim. But as has been stated it is highly unlikely you would overload the system anyway. Bear in mind there have been tenants before you and evidently there has not been a problem, if there is in your particular case it may be that you are using the system in a non normal way.

I would note that the previous tenants were with another LA and on handover to the new LA they reported everything to be in fully working order.

I found bayonet cap fixtures with exposed metal in every bedroom, replaced them obviously. Some so damaged the bulbs would not have held for long.

I found the washing machine to do nothing other than turn on, no controls worked and it just spun constantly.

So my confidence is low as far as any previous electrical maintenance goes!

 

[The Ghost]

I found bayonet cap fixtures with exposed metal

The irony on that is that replaced or not you have still left exposed metal parts that are live. So you have not obviated the problem of exposed live parts. Appliances such as washing machines do not form part of the system inspection.

 

[Iain Kay]

Are you sure it cannot be right. Can you tell us why?

It's seems you do not comprehend the term inrush fully, inrush is associated normally with inductive loads, purely resistive loads have negligible inrush, a typical motor will have an inrush up to 10x the full load current rating so yes it is correct that a 32amp mcb with a 3-5x trip curve will allow an inrush of upto 95amps without tripping and 95-160 amps where tripping may be intermittent.
Don't forget that when we talk about inrush that this is very a very short period of time and is not an indication of how the device handles constant current flow.

I think both of these could be answered together.

I don't claim to have a certified sparks knowledge of inrush, that's for sure, but I do appreciate, prior to now, that it's an extremely short split-second occurrence.

I'm just saying that right now I can't turn off my MCB and turn it back on again.

Let's say I have the max possible load noted previously, 11.45kW, and let's allow for some expansion here for inrush.

I'm no expert but I'd imagine a fridge may require some inrush to get started so lets factor that in at 10x and that takes it up to 800W instead of 80W bringing total to 12.25kW.

The oven, kettle and toaster won't be coming on so drop 7.1kW takes us to 5.15kW.

I do have air purifiers running on that circuit but their load is 60W, so let's say inrush may be 600W each or so to fire up the fans. Total 6.35kW.

The rest of the load? 5x HDR screens @ 120W, let's allow 3x inrush I think for these so 1.8kW bringing total to 8.15kW.

PC PSUs total 1650W at 80% efficiency so lets say 2.1kW if they use absolute maximum possible power in their spec. Then triple it. 6.2kW bringing total to 14.35kW.

Set top boxes, we have around 10, let's say they should pull no more than 50W in operation each so 500W and triple that for inrush giving us 1.5kW. Bringing total to 15.85kW.

Now add in the comms cupboard. PoE switch, switch, modems, etc. That won't be pulling more than 150W at load. Let's triple that to be safe and go for 450W bringing total to 16.3kW.

Based on 7.68kW at 32A then if I'm pushing 96A it should be 23.04kW and 160A should be 38.4kW, am I right?

So surely my currently measly load could not be causing such an inrush?

 

[Pete999]

I would note that the previous tenants were with another LA and on handover to the new LA they reported everything to be in fully working order.

I found bayonet cap fixtures with exposed metal in every bedroom, replaced them obviously. Some so damaged the bulbs would not have held for long.

I found the washing machine to do nothing other than turn on, no controls worked and it just spun constantly.

So my confidence is low as far as any previous electrical maintenance goes!

If you are having problems with whatever in your new Gaff then contact the Land Lord, don't go frugging with it yourself.

 

[Iain Kay]

If you are having problems with whatever in your new Gaff then contact the Land Lord, don't go frugging with it yourself.

Fair enough there mate, this was my initial thoughts on the matter just wondered what my options if any would be should this not be an option.

I've always treated renting right, raise anything serious enough with the LL/LA but anything real easy like changing a lamp holder or light switch, putting extra semi-permanent sockets in places via trunking and fused plug on the end, etc I'll just crack on. Always offered to remove at the end of tenancies, however, most LAs have left in place as far as I know.

 

[The Ghost]

So surely my currently measly load could not be causing such an inrush?

I think to answer those questions you need to attend a course. Guessing and half cocked understandings/conclusions are not really the way to go. With the greatest of respect I would suggest you stick to computing where I assume your abilities and competence lie. Get an electrician in to distribute the load properly at your expense with the permission of the Landlord. Put your computing on a separate supply from the CU spare way so that they become fairly bullet proof. With that amount of equipment you are describing your real problem may lay in the fact that you need different types of RCD as the DC dumped on to the circuit may cause hystereses of the RCD (does not function properly in fault conditions). You may need a type A instead of the usual AC type fitted in domestic premises. There is far more to this than you are soley considering.

 

[davesparks]

I found bayonet cap fixtures with exposed metal in every bedroom, replaced them obviously. Some so damaged the bulbs would not have held for long.

I found the washing machine to do nothing other than turn on, no controls worked and it just spun constantly.

Did you have permission to replace the lamp holders and are you properly insured to do this?

The lettings agency for my house won’t allow me to do any small repair like this without providing a copy of my insurance and I’ve found this to be the norm with most of them.

 

[davesparks]

The load described is more than anyone would reasonably expect for a domestic installation in a two bed flat. If asked to design an installation for a 2 bed flat I certainly wouldn’t design for that kind of load without specific instructions to do so.

To power that much IT equipment properly you will likely need circuits designed for high protective conductor currents with appropriate high integrity earthing.

 

[davesparks]

I really don't want to have power cutting out all of the time on my gear though, lost too many PSUs to that and that's the best case, so for now I've really kept things to the minimum.

If power cuts are damaging the equipment then surely you have a case against the manufacturer for supplying equipment which is unfit for purpose.

Or maybe if the equipment is that sensitive a UPS would be a sensible consideration

 

[The Ghost]

I'm just saying that right now I can't turn off my MCB and turn it back on again.

That fact may point to another problem not load. Or are you saying you had the toaster, washing machine, tumble dryer, oven and all other equipement going when trying to switch on under load? And was you computer equipment part of the load. Or in other words how much load was on the circuit when you tried to switch off and on?

 

[marconi]

Ian Kay - there has been some really good advice ( all at no cost to you) from experienced experts. The property has a satisfactory installation for the typical tenant's electrical requirement. You have an extraordinary IT electrical requirement which I reckon needs a properly designed and installed electrical supply (including UPS and filtering maybe) which is beyond what the LA is contracted (or is reasonable for them) to supply at their cost. The long and the short of (it seems to me) is that the dedicated wiring for you to run your IT equipment is for you to fund once you have the LA's agreement to install it. It is for the LA to appoint an electrician to do the design, installation and testing and inspection. The LA then bills you. Consider though that the LA may want the new wiring removed and the property made good when you quit, once again at your expense - it depends on what it looks like.

 

[Iain Kay]

Thanks to everyone for your responses.

Clearly my level of understanding of the maths at play here is not up to scratch to make an informed decision myself.

This is why I wanted to pose it to the pros because I felt that there is a problem here but knew that in all likelihood my thinking is almost certainly flawed, but couldn't see it.

I think that a lot of responders are right, a dedicated circuit for the computing equipment with some UPS protection is likely the best course of action. I've been looking into UPS but again wanted to know what I was working with power wise before going ahead with anything there.

If I move everything into the hall cupboard then it should be a relatively minimal job for an electrician, appointed by LA, to run a circuit from the CU which is within meters of the cupboard.

I think that this is the route to go, and given that I did make the LA aware of my requirements I'd like to hope they will accommodate it given it's a long term lease, albeit potentially fully at my own expense which I did expect anyway and doesn't differ from me wanting to do this in an owned property.

Just disappointing there's not already more in place here, as I say it's a strangely minimal configuration for me to encounter.

Will contact LA about my concerns and see what we can come up with.

Thanks again, really appreciate all of the advise and I will read over all of it again.

 

[Iain Kay]

I think to answer those questions you need to attend a course. Guessing and half cocked understandings/conclusions are not really the way to go. With the greatest of respect I would suggest you stick to computing where I assume your abilities and competence lie. Get an electrician in to distribute the load properly at your expense with the permission of the Landlord. Put your computing on a separate supply from the CU spare way so that they become fairly bullet proof. With that amount of equipment you are describing your real problem may lay in the fact that you need different types of RCD as the DC dumped on to the circuit may cause hystereses of the RCD (does not function properly in fault conditions). You may need a type A instead of the usual AC type fitted in domestic premises. There is far more to this than you are soley considering.

Thanks for this Vortigern. You are right on that, my knowledge here is not enough to give me an answer.

As I gain more I will maybe look back on this and laugh at myself :/

Thanks again.

 

[littlespark]

In defence of my post #10, and the response on #14, the OP has stated since that the circuit has tripped.
I also said the OP would be told he was overloading the circuit, which he probably has.

The OP is in Edinburgh? so an EICR should have been done before the tenancy started, the tenant has the right to see that.

We don't know, from afar, what may have happened in this property, but it still looks strange having such a big CU with so many spare ways.

 

[Iain Kay]

Hey again all,

I've got ahold of an Appliance Testing Certificate dated 12/09/2017 covering: Oven, Gas hob, Cookerhood, Washing machine and Fridge.
All passed visual inspection, all ">50 Pass" and all status pass.

Also an EICR dated 12/09/2017. Overall assessment of the installation in terms of it's suitability for continued use: Satisfactory.

If you feel any of the particulars would be interesting, let me know what and I'd be happy to share.

Edit: I've been reading over this and this contradicts my fairly concrete findings.

Specifically "16. Schedule of circuit details and test results"

This implies that there are two socket circuits with B32s. This is not the case at all as far as thse connections go because everything is turned off when I operate a single B32.

According to this page the shower should be on the B40 but it's on the B32.

It looks like this I can indeed raise as this is not operating as per the EICR reports it should.

 

[Octopus]

^^

What do you mean I have got a hold of ?

This is getting smelly imho

 

[Iain Kay]

^^

What do you mean I have got a hold of ?

This is getting smelly imho

Nothing fishy, it's been handed over by LA at some point over the course of moving in but probably due to my somewhat rushed organisation I did not have this with any of the other documentation I received.

Found a copy in a random envelope also containing the inventory.

Wish I'd found this sooner as it's definitely not matching up with my findings which only makes me want to query things more.

Contains full "details of the client" matching my LA and "address and details of the installation" match my rental.

 

[littlespark]

now it sounds fishy. EICR says 2 rings.
Have you made a mistake when you turned off the circuit... did all sockets go off?

Purely imagination here... faulty MCB in the past, and the electrician at the time doubled them up to get them running again.... but why when theres so many spare ways?

 

[Iain Kay]

The MCB in position 13 is clearly labelled as the second socket ring on the EICR but it's operating the shower.

I turn on the shower, flip that B32 off, boom showers off.

The B40 that is supposed to be shower, it's been flipped off for a few days since I tested this and the showers worked fine since.

It's as if the B40 has gone bad and somebody has wired the two rings into position 12 and shower into 13 without swapping MCBs to be honest.

 

[littlespark]

As I mentioned earlier, an EICR should be performed between tenancys to pick up on tenants "repairing" faults like this.
Is the inventory you unsurfaced dated the same? or have you not got the current one.
Bring it up with LA, im sure they will give answers