RTS meter makes clunking noise every hour, why ?

Gotcha, yeah that sounds much more like how it should be behaving!

If you’re happy to live with that then you should be good to go. Otherwise, you may be able to get some kind of sound dampening in the affected space to potentially neutralise it a bit.

What with your manifold obfuscations and the general blurriness of the photos, I’m having a bit of trouble deciphering your photos!

For a start, the EDMI box is on the left as I see it, with the KAIFA units on the right!

The EDMI unit is the comms hub, connected to the meter by means of the KAIFA FL100 Flying Lead. I suspect the engineer thought it would be easier to do this rather than juggle all those 25mm cables to make room for the comms hub on top of the meter where it would normally be. (All it does is provide a 12V DC supply to the comms hub; the communications from the meter are done over Zigbee. I don’t know why it’s made so complicated ...)

There appear to be six meter tails, which is unusual. The left-most two, a grey/blue pair, are the incoming line and neutral (N2) feeds from the service head (the black unit below the trunking).
  

Then guesswork takes over. N3 is the constant circuit’s neutral, and its line is the very dark one following it to the left and round an S bend to the white Henley blocks. That leaves two grey-sheathed ones. I suppose that the one closest to the camera is the line for the switched circuit, probably supplying the storage heaters. That switch is inside the meter and although it’s most probably a 100A beast, it will be less noisy when activating than the big old monster Luke referred to. That leaves a grey sheath with not much inside it, also coming from the right-hand end of the terminal enclosure. This could be a 2A line to the aforementioned control unit, e.g. for the hot water heater. Your electrician will be able to explain all this when he next comes to visit.

In any case, this is most probably a variant of the Kaifa MA120B (not MA100 as you wrote above), the ‘B’ signifying the fifth tail for the switched circuit. The sparse documentation I’ve been able to find indicates that the variant with buttons arranged vertically is V1, while the later V2 has buttons arranged horizontally. The first two digits of the meter serial number (MSN) which you so carefully hid from us give the year of manufacture; it may well be that the latest variants have reverted to vertical buttons again.

If I were you, I’d take some good clear photos of the whole lot, including the flimsy Meter Exchange Label to the left of the comms hub. You may have to refer to the readings it records at some stage in the future, and those labels have a habit of going missing over the years. 

Ah well, the left right mistake was a test to see who is observeant. :-)

I've taken some better resolution pictures to help.

The hot water is not controlled by the storage heater circuit, it can be turned on and off at will, and by a timer unit.

It for sure says MA120 and not MA120B :-)
 

There is a big switch on the wall, top right.

Hey ​@shetland,

Do you think it may be the control circuit like Luke suggested?

If the control circuit is the one that goes via this:

Eaton MEM Autoline 42ALCDP Double Pole 80A 250v AC1 unit

And then onto the consumer unit where the storage heaters are wired into, top left.

Then it must be, since the meter has been replaced.

Unless the new meter also clunks !

Do they clunk ?

It’s hard to be sure where the noise is coming from, since both units are so close to each other.

So it does, thanks. If ​@Lukepeniket_OVO is still watching, he might have some ideas about how to stuff six tails into four ports and, indeed, why:
  

I can only imagine that the control switchgear was there to help RTS protect the fragile island network from periodic overload. That may still be necessary, of course, so it will be interesting to hear what happens when the plug is finally pulled on RTS.  

Hey all, 

5&6 are in the ALCS connection which means its turning on a contactor, the contactor above is named ‘heating control circuit’, which when that is energised it makes the ‘clunk’ =]

Thanks, Luke. I know that’s what it looks like and what I initially thought when I couldn’t read the meter type. I can’t find any documentation for these meters, so I’m a bit surprised that the ‘non-B’ variant has a load control switch at all even if there’s no internal contactor:
  

Any idea why this Kaifa would have been installed instead of everybody else’s Aclara?

Do engineers routinely have flying leads in the van? I’m sure there are plenty of scenarios when it could be really helpful.

Hey bud =]

Yes it'll be down to stock levels, we haven't had Aclara 4T in a while so we are back to Kaifa/L&G.

Yes we do have flying leads and will also be getting longer versions aswell =]