disappointed of lincolnshire Sunamp - new label showing only C rated energy efficiency

[Nickfromwales]

2 minutes ago, Ed Davies said:

Beginning to wonder if that 90% setting was originally intended to  be when it's discharged to 90% state of charge (i.e., 10% discharged) but it got misinterpreted by the programmer/technical writer and the management at Sunamp haven't yet realised what's happened.

Not according to my conversations. I’ll ask again when the ‘salty box of clever goo’ company reemerges with their hangovers  

[Triassic]

I wonder how long it’ll be before the Salty company is taken over by Google?

[ProDave]

24 minutes ago, Triassic said:

I wonder how long it’ll be before the Salty company is taken over by Google?

A takeover would not surprise me, often happens to start ups with a good idea when someone big wants that technology.  A few years ago I would have predicted Kingspan as the new owner.

[Onoff]

6 minutes ago, ProDave said:

often happens to start ups with a good idea when someone big wants that technology

 

As in wants to kill it?

[ProDave]

Just now, Onoff said:

 

As in wants to kill it?

Sadly that is sometimes the case.

[Triassic]

Or it’s just a way of buying the PI, the research, the people and the manufacturing capability, cheaply!!

[Ed Davies]

1 hour ago, Nickfromwales said:

I’ll ask again when the ‘salty box of clever goo’ company reemerges with their hangovers

 

Bearing in mind that doesn't happen in Scotland until about a week after New Year.

[Triassic]

Sunamp Tweeted this yesterday.

 

“Planning an update in the New Year that fully implements PV self-consumption mode for: 

 

Combi (opportunity charge from PV) Electric hot water (as above plus timed charge periods - may require external timer tbc)

 

Happy Christmas ? ? ? ?”

 

 

im still confused!

[Barney12]

12 minutes ago, Triassic said:

Sunamp Tweeted this yesterday.

 

“Planning an update in the New Year that fully implements PV self-consumption mode for: 

 

Combi (opportunity charge from PV) Electric hot water (as above plus timed charge periods - may require external timer tbc)

 

Happy Christmas ? ? ? ?”

 

 

im still confused!

 

@Nickfromwales flogged them that load of cheap Chinese timers ?

[Onoff]

36 minutes ago, Triassic said:

Sunamp Tweeted this yesterday.

 

“Planning an update in the New Year that fully implements PV self-consumption mode for: 

 

Combi (opportunity charge from PV) Electric hot water (as above plus timed charge periods - may require external timer tbc)

 

Happy Christmas ? ? ? ?”

 

 

im still confused!

 

Nice touch of Sunamp to send Jeremy the hamper I thought...

 

[Declan52]

There is a guy on their Twitter page called Richard Phillips who is an expert,  and seems to be answering lots of questions.  Not sure if he works for them or not  or maybe is he a member here by any chance. 

[Onoff]

12 minutes ago, Declan52 said:

There is a guy on their Twitter page called Richard Phillips who is an expert,  and seems to be answering lots of questions.  Not sure if he works for them or not  or maybe is he a member here by any chance. 

 

Seems he did work for them:

 

https://www.linkedin.com/in/richard-phillips-01368547

[Onoff]

Interesting Sunamp comment saying don't get too hung up on %ages:

 

https://jumpic.com/hashtag.php?q=Sunamp

[Triassic]

14 minutes ago, Onoff said:

Interesting Sunamp comment saying don't get too hung up on %ages:

 

https://jumpic.com/hashtag.php?q=Sunamp

They go on to say......

 

 “The true action of those settings is closer to “don’t charge unless mostly empty” (‘ON’) and “charge when still nearly full” (‘OFF’). The latter is clearly better with a PV self-consumption device. Even better mode planned 2019.”

 

Well that clears that up then!!

[Declan52]

36 minutes ago, Onoff said:

 

Seems he did work for them:

 

https://www.linkedin.com/in/richard-phillips-01368547

Think that's a different guy. 

[newhome]

Reply to my Tweet 

 

 

[newhome]

What’s the next question to ask then ?

[Onoff]

 

40 minutes ago, Triassic said:

They go on to say......

 

 “The true action of those settings is closer to “don’t charge unless mostly empty” (‘ON’) and “charge when still nearly full” (‘OFF’). The latter is clearly better with a PV self-consumption device. Even better mode planned 2019.”

 

Well that clears that up 

 

Looking at this in the cold light of day you have early adopters accepting that they're guinea pigs and that their feedback is an essential part of the R&D process.  There is then a perfectly reasonable expectation that the newer models should work just as well as the old. There's then likely a section of less tech orientated people, perhaps with money to burn one may term "demanding clients", expecting it to work out of the box with no faults or glitches. Chuck in people who are a mix of all these traits. If in the early new year Sunamp come up with a definitive fix then on the grand scale of things then that's pretty quick and hats off to them. 

[Nickfromwales]

1 hour ago, newhome said:

What’s the next question to ask then ?

Why does my cats breath smell of cat food ?

 

[Nickfromwales]

3 hours ago, Barney12 said:

 

@Nickfromwales flogged them that load of cheap Chinese timers ?

One step closer to funding my plans for worlds domination. 

‘Watch your backs, my future minions”.

[epsilonGreedy]

On 24/12/2018 at 18:55, Triassic said:

Or it’s just a way of buying the PI, the research, the people and the manufacturing capability, cheaply!!

 

 

Acquisition is the new R&D as they say in Silicon Valley.

[Jeremy Harris]

On 24/12/2018 at 17:33, Ed Davies said:

Beginning to wonder if that 90% setting was originally intended to  be when it's discharged to 90% state of charge (i.e., 10% discharged) but it got misinterpreted by the programmer/technical writer and the management at Sunamp haven't yet realised what's happened.

 

 

That was exactly my thought when I first discovered we had a problem (as in the shower ran cold) and emailed Sunamp for clarification of the exact meaning of the Option 1 setting.  Their reply was that the wording in the manual:

 

Quote

3.3.1.  Controller type: UniQ_SBC_01 (Electric storage water heater)

•  Heating from bottom to top
•  Cooling from top to bottom
•  Option 1 on: demand signal generated when battery is approx. 90% depleted
•  Option 1 off: demand signal generated when battery is approx. 50% depleted

 

means what it says - that 90% depleted, or 50% depleted, is really 10% SoC and 50% SoC.

 

The email I received did say that the 50% figure is approximate, though, and my guess is that this may be because it's much harder to determine the SoC once the unit is not charging but being used to deliver DHW, often sporadically.  The unit doesn't have any way of directly detecting when hot water is being drawn off, as all it measures is three temperatures inside the cell.

 

The bottom line is that we ran out of hot water as a direct consequence of the Sunamp controller not switching the contactor on to allow an early morning boost.  Since adopting the procedure of turning the unit off, then on again, every day, just after we've used the shower, we've had no further problems at all.  The unit almost always switches to charge acceptance mode when this is done, allowing utilisation of any excess PV generation, and also allowing the timer-controlled early morning boost to work, if there hasn't been enough excess PV generation to charge the unit up.

[Ed Davies]

1 hour ago, JSHarris said:

…and my guess is that this may be because it's much harder to determine the SoC once the unit is not charging but being used to deliver DHW…

 

Indeed, this is always a problem with PCM energy storage: it's easy to get a fix on the SoC at the ends of the scale but much harder in the flat-temperature phase-change part in the middle. Similar with many battery chemistries. The only way, really, is counting the joules in and counting them out again and, as you say, counting them in is easier though I don't think the Sunamp controller has a measure of the amount of variable current coming from the PV. With direct mains charging they can assume 2.7 kW, or whatever, but that doesn't really work for PV.

[Nickfromwales]

19 minutes ago, Ed Davies said:

 

Indeed, this is always a problem with PCM energy storage: it's easy to get a fix on the SoC at the ends of the scale but much harder in the flat-temperature phase-change part in the middle. Similar with many battery chemistries. The only way, really, is counting the joules in and counting them out again and, as you say, counting them in is easier though I don't think the Sunamp controller has a measure of the amount of variable current coming from the PV. With direct mains charging they can assume 2.7 kW, or whatever, but that doesn't really work for PV.

I think that flooding the cell with thermistors and getting an accurate cell-wide average temp reading could work well. Do away with the 50/90 setting ( for the PV > DHW model only ) and just have one max threshold where anything at or close to 75^oC ( cell average temperature ) allows electrical input. 75^oC or above = satisfied. This remains open-ended though, as you really need a SoC indicator to correctly identify if you still need to perform a manual boost or not ( insufficient excess PV in that 24hr period ). Other than that, boost is a guessing game.

 

At least with a load of thermistors the ctrl PCB would have the ability to gather and offer this info to an LCD display, giving the end user at least some indication. With a bit of additional logic and an integral clock, the unit could self diagnose and perform its own boost cycle where it knows it hasn't received sufficient PV input. I imagine SA would reply that you don't get that with an UVC or dumb copper tank, but with those there is no box of tricks actively stopping energy input at any point, just excess PV chucked at a dumb immersion heater that has its own thermostat. I think SA need to adopt that simple approach and bin the complex control logic ( and the not so complex means of temp referencing that they currently are suffering from with the seemingly unreliable 3 thermistors on the daisy chain ). 

 

This isn't so much of a problem if SA is an excess only device eg pre-heat to an UVC or Combi boiler, but very much so if this is the only means of providing DHW to a dwelling.

[Jeremy Harris]

1 hour ago, Ed Davies said:

 

Indeed, this is always a problem with PCM energy storage: it's easy to get a fix on the SoC at the ends of the scale but much harder in the flat-temperature phase-change part in the middle. Similar with many battery chemistries. The only way, really, is counting the joules in and counting them out again and, as you say, counting them in is easier though I don't think the Sunamp controller has a measure of the amount of variable current coming from the PV. With direct mains charging they can assume 2.7 kW, or whatever, but that doesn't really work for PV.

 

 

AFAICS, the controller has no means of measuring energy in or out.  The connection to the heating element is directly from the input cable, via the contactor, to the heating element, so it can't sense current (or energy). 

 

With my electric motorcycle battery management system I can measure energy in and energy out (as well as other parameters, such as cell voltage and temperature) and this is a useful guide as to SoC both when charging and discharging.  The main reason for doing this was to give the bike a "fuel gauge", but it's equally useful when only partially charging the battery pack.  When the pack is being fully charged it just shuts the charger down at the end of the cell balancing stage, and sets the SoC to 100%.

 

With the addition of a flow rate sensor plus two temperature sensors, one each in the water inlet and outlet, it should be possible to measure the discharge energy, and combined with measuring the voltage, current and time for the heating element then it should be fairly straightforward to measure the charge energy.  The losses are probably fairly predictable, so could be accounted for over time, so giving a reasonably accurate SoC status indication at any time.  Combined with temperature measurement, primarily as a safety feature, to prevent the PCM from being over-heated, it should be possible to get fine control over the charging system.

 

Whether that's worth it is debatable, though.  My feeling at the moment is that the simple temperature measurement system, combined with a bit of logic that just does something like "IF contactor has been off for > x hours THEN turn contactor ON", with the existing "PCM fully charged" logic over-riding that to turn the contactor off, as it does now, would work well enough for pretty much any use case I can think of.