Electricity Usage meter

[ban-all-sheds]

How does having heating provided mean that they won't want kettles?

 

[Steven Prentice]

Slow night eh B-A-S?

Just for clarity, if the landlord stipulates that there is to be no heating devices in the rooms for example a kettle, and there should be no requirement for heaters since he provides the heating then it is possible to limit the electrical use by using a smaller breaker. Actualy now I write that again, it is not a hard concept to understand first time around.

And as for kettle or a toaster, the landlord also provides a kitchen where most normal people keep their kettle, and toasters and so on. They can easily make a brew in there.

 

[ban-all-sheds]

Slow night eh B-A-S?

Just for clarity, if the landlord stipulates that there is to be no heating devices in the rooms for example a kettle, and there should be no requirement for heaters since he provides the heating then it is possible to limit the electrical use by using a smaller breaker. Actualy now I write that again, it is not a hard concept to understand first time around.

But apparently the concept that a "kettle is not a heater" is too hard for some people to understand. Or a toaster.

If you disagree, I'd love to see you live in a property where the heating is provided by a kettle and a toaster.

I expect you also struggle to understand the concept that MCBs are not to be used as load limiting devices.

 

[Steven Prentice]

MCBs are not to be used as load limiting devices.

That is exactly the point of any protective device, to limit the load (or the current) in the circuit. It is a common practice to have the protective device set below the maximum that the installation can handle.

 

[JohnW2]

My crystal ball foresees a dissenting view!

Kind Regards, John

 

[bernardgreen]

That is exactly the point of any protective device, to limit the load (or the current) in the circuit.

to protect the installation from damage from cables over heating due to a high current caused by a fault.

Using an MCB as an automatic load shedding switch is NOT recommended as frequent operation of an MCB can alter the operating parameters such as the current at which the MCB trips. If you need to limit the load then use a device designed for frequent operation, such as a current sensor and a contactor

 

[ban-all-sheds]

My crystal ball foresees a dissenting view!

Your crystal ball was working.

to protect the installation from damage from cables over heating due to a high current caused by a fault.

Using an MCB as an automatic load shedding switch is NOT recommended as frequent operation of an MCB can alter the operating parameters such as the current at which the MCB trips. If you need to limit the load then use a device designed for frequent operation, such as a current sensor and a contactor

 

[JohnW2]

If you need to limit the load then use a device designed for frequent operation, such as a current sensor and a contactor

That makes sense, but are devices such as you describe readily available off-the-shelf - i.e. a 'current sensor' which provides a binary output ('on' or 'off') depending upon whether the current exceeds some (perhaps adjustable) threshold value?

Kind Regards, John

 

[bernardgreen]

Yes

This https://www.tele-online.com/en/case-studies/electronic-load-shedding-relay-prevents-overloads/" may be over the top for a "domestic" but I am sure a bit of google with "load shedding" or "load limiting" will find a more suitable device.

 

[Steven Prentice]

Using an MCB as an automatic load shedding switch is NOT recommended as frequent operation of an MCB can alter the operating parameters such as the current at which the MCB trips. If you need to limit the load then use a device designed for frequent operation, such as a current sensor and a contactor

I would agree with you there but in the situation of a bedroom, if the landlord has specified there are to be no heater or other heat generating devices (such as a kettle) - typical domestic high load appliances - the total load for the room and hence the current should never be expected to exceed 6A, and possible 4A... and in this normal situation there would not be frequent tripping.


Yes, using a device specifically designed to limit the load would be best but on the information in the original posts, this is a simpler, cheaper solution. it might be better since the tenant will very quickly learn that plugging in an appliance that draws a large current will trip their electricity, and they will stop trying to use them.



Just trying to help rather than knee jerk reaction of "no don't do that", far better to say "best not to do that, try this"

 

[JohnW2]

Yes, using a device specifically designed to limit the load would be best but on the information in the original posts, this is a simpler, cheaper solution. it might be better since the tenant will very quickly learn that plugging in an appliance that draws a large current will trip their electricity, and they will stop trying to use them.

That's undoubtedly true, and probably means that, in practice, using an MCB for this purpose would probably be OK in the situation described, because only an idiot of a tenant would keep on plugging in something which they had discovered trips the MCB.

However, even if one takes that view, it would only be because it was "simpler and cheaper". Despite what you say, it would not be 'better' in any other sense, since the tenant would equally learn by experience if it were 'proper technology' that was doing the current limiting.

Kind Regards, John

 

[Deleted member 18243]

The type of meter shown in the OP is not intended for fitting into consumer units - they are DIN rail mountable but should go into a panel or an enclosure like this:

https://www.spwales.com/enclosures/abb-mistral-4-module-din-rail-meter-enclosure

I suppose your consumer unit could be modified to allow these to be fitted, but it would be easier to fit them into a separate enclosure.


This is another small DIN rail mount meter but of better quality than the Chinese one shown:

https://www.spwales.com/single-phase/ytl-dds353

(You could put your three meter modules into one enclosures).


Another type of meter is wall mounted, but you would need three of them:

https://www.spwales.com/single-phase/emlite-dragonfly

Alternatively, I wonder if a three phase meter could be used, because these display the kWh for each phase separately as well as adding them up? You have not got three phases but you would still be putting three separate lines into it. Here is one such:

https://www.spwales.com/three-phase/iskra-mt174-m

With all of these you will have to take cables out of the consumer unit into the meter, and then out of the meter onward to the rooms.

 

[JohnW2]

Alternatively, I wonder if a three phase meter could be used, because these display the kWh for each phase separately as well as adding them up?

Mine doesn't, and I can't see how they could - unless it was, in fact, three separate single-phase meters within the same enclosure.

A true 3-phase meter, like mine, measures the vector sum of currents in all three phase conductors, so knows nothing of currents in the individual phases.

Kind Regards, John

 

[SimonH2]

Going slightly off topic, I would also suggest each room should have it's own RCD - ie be on an RCBO. I imagine it would be "more than a little annoying" to have your power go off because someone else has a faulty appliance. Even more so if you have to wait for the landlord to come round and reset it.
And as I write that, there comes another thought ...
If the OP did fit a smaller MCB, then the tenant couldn't just keep resetting it. It should become obvious to the landlord if they keep tripping it and the landlord can then discuss with them what they are using/doing to trip it.

 

[AlanE]

This is another small DIN rail mount meter but of better quality than the Chinese one shown:

https://www.spwales.com/single-phase/ytl-dds353


Another type of meter is wall mounted, but you would need three of them:

https://www.spwales.com/single-phase/emlite-dragonfly

Both of the above are considerably cheaper here- https://www.universalmeterservices....ers-c-3.html?zenid=33tdbjkl3612pu7071h4vimc04