Aclara smart meters - your guide

So you’ve recently picked up a shiny new smart meter then? Nice one! And if you’re reading this, you’ve probably gotten lucky in that your new smart meters are from Aclara and Flonidan. Double bonus!

Aclara is one of the most popular smart meter brands in the UK but they only do electric meters rather than gas meters. Fortunately, they’re often paired up with Flonidan gas meters which are equally good. But that story is for another time…

But how can you tell which Aclara meter you’ve got, other than the most important thing about whether it’s a SMETS1 Aclara SGM1300 Series or SMETS2 Aclara SGM1400 Series? Well, unlike a certain smart meter brand that loves to be really strange, Aclara has possibly the most helpful and ingenious model name/numbering scheme of the lot!

The first thing you’ll definitely want to know is of course if you’ve got S1 or S2. We’ve got some guides for that which I’ve linked above. But thanks to a certain smart meter friend at OVO’s office, a 108 page long SMETS2 Aclara user guide (yep, really is over 100 pages!) and the document library over at SmartMe, I’ve learned some new tricks.

So here’s my quick guide to how the Aclara model numbering works and what it all means. Trust me, they’re not just for show! As these are all from the official SGM1400 Series user manual that’s available on SmartMe and originally written by Aclara, I’d like to credit both Aclara and SmartMe for providing me with the details that helped me to create this guide.

So how does it all work?

Very cleverly! It’s a little bit complicated to explain, but I’ve also given some examples further down.

When you look at the model number, you’ll often see things like SGM1311, SGM1412-B or SGM1416-B. They might not sound like they mean anything, but let’s dig a bit deeper. There are five parts that make up the model numbers. They’ll often be formatted as SGMABCD-E. It breaks down into five groups which are SGM, AB, C, D and E

SGM (and SGC)

This bit identifies what type of product you’re looking at. SGM is basically a code that Aclara uses to identify products as being their smart meters. This is important because S1 Aclara meters would also have an Aclara Comms Hub on top, such as having an Aclara SGM1311 Smart Energy Meter with an Aclara SGC1311 Smart Communications Hub. In these cases, the bit with SGM is the meter itself, while the bit with SGC is the Comms Hub. This only applies to S1 however - S2 Aclara meters will always have an S2 Comms Hub on them from brands such as Toshiba or WNC. In addition, the numbers after SGC usually aren’t of much relevance because they tend to match the meter anyway. Everything below doesn’t apply to the Comms Hubs for this reason. But it can help to identify the meter at least!

AB

These are the first two numbers you see just after SGM. They represent the model family that the meter belongs to. For example, S1 versions will often have 13 in this slot, while S2 will have 14 instead. If Aclara later releases a new model family, these two numbers will be changed on that new family to help you to tell them apart from existing ones (it might go 15 for example!).

C

This number represents how many elements are present in the meter. If you’ve got a Single-Phase Supply, it will almost certainly be just the one element and this number will be 1. But if you have a Three-Phase Supply, it’ll be 3 instead. But there are edge cases where two elements might be present and this number will be 2 in those cases. But I don’t think I’ve ever heard of a Two-Phase Supply in the UK! :)

If you’ve got 2 in this slot, that’s almost certainly because there’s a secondary load being served by the meter, possibly on a different rate or even being controlled completely independently from everything else - but you probably won’t have the 2A Auxiliary Relay either.

D

This number represents how many relays are present in the meter. If you’re on a regular Single Phase Supply with no Storage Heaters, no Economy 7 or really any other kind of fancy setup, you’ll probably only have the one relay and this number will be 1. If you’ve got Single Phase with Storage Heaters however and the meter is controlling them, there’ll probably be two relays (one main 100A relay for most of your house and a second 2A Auxiliary Relay that controls the Storage Heaters) and this number would be 2.

But what if your setup is even more complicated? And what if you’ve got Water Heaters and Storage Heaters which are controlled independently of everything else? Well, you might even have six relays for all that lot so the number would be 6. In other words, you’ve probably got either the Aclara SGM1416-B if you’re on Single Phase or if you’re on Three-Phase it could even be the SGM1433-B. You’d have to be pulling an awful lot of super green eco juice from the National Grid to need that beast though!

(dash or - separator)

This doesn’t really mean anything interesting. It's purely used to split things up but can otherwise be ignored. 

E

This one’s just the Family Version and usually gets incremented if there’s a hardware revision of some kind. It also uses letters rather than numbers. Rather cleverly, Aclara seems to have designated all their S2 meters in the SGM1400 Series with a B in this slot - which is not present on the S1 meters in the SGM1300 Series. Magic!

So what does that mean in practice?

Well, firstly that’s the techy bit over (phew!) and now I can give you some real-life examples that put this all into perspective.

If we take my old meter Pikachu for example, which was an S1 Aclara, I can demonstrate how this works out. Pikachu was a SMETS1 Aclara SGM1311 with an Aclara SGC1311 Comms Hub that was originally installed by SSE a few years ago. From the model number, you can identify that it was a Smart Meter due to the SGM (and the SGC indicated an S1 Aclara Comms Hub!), it was an S1 due to 13, and that it had a single element and a single relay due to being on a Single-Phase Supply with no Storage Heaters because the last two numbers were 11.

Likewise, my current meter Raichu is an Aclara SGM1411-B with a WNC SKU1 Cellular Comms Hub. S2 Comms Hubs don’t fall into this guide, but we have other guides here if you’d like to learn more. If you compare the model numbers, the only differences between Pikachu and Raichu are that Raichu is an S2 due to the 14 numbers and the B on the end. But other than that, it’s pretty similar to Pikachu because it still has the same 11 numbers on the end.

But if you’ve got a simple Economy 7 setup with a SMETS2 Aclara, you might have the SGM1412-B because it features the extra Auxiliary Relay for the control circuit or even the SGM1416-B for some serious Storage Heater and Water Heater action! 

On the other hand, if you’ve got a Three-Phase Supply, Storage Heaters that the meter controls, a huge hunger for eco juice and a very complicated setup, you might even have the Aclara SGM1433-B which is basically the massively overengineered variant that can do almost anything... Except for making your lunch or automatically paying the bills for you! Aclara are probably still working on developing those features.

Why does Aclara do this? Surely they’re all just the same meter… Right?

Muhahahahaha, that’s what they want you to think, right before they sneak up and take over the world with an evil genius plan for World Domination… Oh wait, sorry! That’s actually my plan which I almost revealed! 

Aclara actually hasn’t said why they use this strategy and there’s an air of mystery to it.  And if you think about it, the way they do the model numbers is a stroke of genius. Plus, if you compare it to a certain other smart meter brand which constantly recycles the exact same model numbers across 50 billion products, I think I know which one I’d prefer!

Cool, do you happen to have a list of all the known models?

Yep! I can’t promise that it’s a totally complete list, but here’s all the known S1 and S2 Aclara meters that I’m aware of - and what they’re capable of for this purpose.

S1 Aclara - SGM1300 Series

• SGM1311 (aka Pikachu) - S1 Single-Phase Single Load meter for general purpose use where no fancy setups are needed. Almost always comes with an S1 Aclara SGC1311 Smart Communications Hub. This model is confirmed to be adopted by DCC to run as S1+ in the future and most of these ones should be fully migrated soon.
• SGM1312 - S1 Single Phase meter with a 2A Auxiliary Relay to enable control of Storage Heaters for Economy 7 purposes. These meters will be migrated to DCC along with the entire Aclara SGM1300 Series meters and they also come with an Aclara SGC1312 Smart Communications Hub
• SGM1322 - S1 Single Phase Twin Element meter for specialist use cases like having a secondary load on a different tariff. These meters will be migrated to DCC along with the others

S2 Aclara - SGM1400 Series

• SGM1411-B (aka Raichu) - S2 Single-Phase Single Load meter for general purpose use where no fancy setups are needed. Usually comes with a WNC or Toshiba branded Comms Hub (either SKU1, SKU2 or SKU3)
• SGM1412-B - S2 Single Phase meter with a 2A Auxiliary Relay to enable control of Storage Heaters for Economy 7 purposes. Usually comes with a WNC or Toshiba branded Comms Hub (either SKU1, SKU2 or SKU3)
• SGM1415-B - S2 Single Phase 5 Terminal meter with a 2A Auxiliary Relay for controlling storage heaters
• SGM1416-B - S2 Single Phase 5 Terminal meter with a 2A Auxiliary Relay for controlling storage heaters
• SGM1422-B - S2 Single Phase Twin Element meter for specialist use cases like having a secondary load on a different tariff. Usually comes with a WNC or Toshiba branded Comms Hub (either SKU1, SKU2 or SKU3)
• SGM1431-B - S2 Three-Phase Single Load meter for general purpose use where a Three-Phase Supply is needed. Usually comes with a WNC or Toshiba branded Comms Hub (either SKU1, SKU2 or SKU3)
• SGM1432-B - S2 Three-Phase meter with a 2A Auxiliary Relay to enable control of Storage Heaters for Economy 7 purposes and where a Three-Phase Supply is needed. Usually comes with a WNC or Toshiba branded Comms Hub (either SKU1, SKU2 or SKU3)
• SGM1433-B - S2 Three-Phase 5 Terminal meter with a 2A Auxiliary Relay for controlling storage heaters and the ability to control water heaters independently and where a Three-Phase Supply is needed

Does this mean you can help me to know how my meter is set up more easily?

Yup! And going forward, I’ll be using this trick alongside the other strategies such as counting the cables. I’ve only recently learned about this ingenious numbering strategy, but I wanted to share it on the forum as it will prove useful. You can also check out page 17 of the S2 Aclara User Manual if you’d like to know more.

How about other smart meter brands? Can this magic trick work with those ones too?

As much as I’d love to say yes, I’m afraid I can’t. Aclara is the only manufacturer that we know of which uses this kind of naming/numbering scheme. Because no other manufacturer does this, Aclara is the only one which allows this wizardry to work.

Technically speaking, it’s also only relevant to electricity meters rather than gas meters anyway, since there’s a lot less possible combinations with a gas meter! And I’ve definitely never heard of a three-phase gas supply! 

The only two types of gas meter that exist (ignoring smart capability) are Diaphragm and Ultrasonic but that’s for another guide. What I will say is that if you’ve got a Flonidan UniFlo gas meter, you’ve got the Diaphragm type, but if it’s a Flonidan SciFlo, you’ve got the Ultrasonic type. 

On the plus side, that means Aclara really does think about making their stuff user friendly and reinforces my opinions about Aclara being the best smart meter brand in the UK - they're certainly the most helpful!

I’m still a bit confused though. Can you do some puzzle solving for me?

If there’s one thing I love just as much as bug hunting, it’s definitely puzzle solving! 

If you’ve read this guide and still need a bit more help, we’ll definitely be happy to give you a hand. Please feel free to post on the forum and we’ll take a look. If you can provide some snaps of your meters too and post them at the same time, that makes it even easier for us.