SunAmp : Snog, Marry, Avoid?

[Pete]

14 minutes ago, AnonymousBosch said:

 

I'll try reading, and summarising, this today. Want something done? Ask a busy person. 

Pete, I think the army did us both proud in terms of injecting energy into difficult situations - wouldn't mind some more of that now. 

I was not cannon fodder Ian, I was a member of the senior service floating around the world!!

[Ed Davies]

3 hours ago, JSHarris said:

… has been changed to a very different relay in the newer controllers.

 

You've received the new controller?

[Jeremy Harris]

1 minute ago, Ed Davies said:

 

You've received the new controller?

 

No, not yet, but I've been sent a photo of the inside of it, so can see that they've changed the contactor for a larger relay.

[TerryE]

I am very happy with my 2 × SunAmp PV, but reading this thread, then if I was having to start again with SunAmps, then I'd be tempted to stick with the UniQ 9 HW using a external Willis and circulating pump to heat it.  That way I could have precise control of the heating strategy.

[Russdl]

31 minutes ago, TerryE said:

I'd be tempted to stick with the UniQ 9 HW using a external Willis and circulating pump to heat it.

 

That sounds an interesting solution to the current issues, what would be the down side? Greater heat loss?

[Jeremy Harris]

2 hours ago, Russdl said:

 

That sounds an interesting solution to the current issues, what would be the down side? Greater heat loss?

 

Not enough to worry about, I think.  We've discussed it before as a way to make a reliable PCM charging system, as it's the way the Sunamp PV works.  There are some things to watch out for, and the most critical is managing the charging water temperature and flow rate, especially if fed from a variable power source, like excess PV generation.

 

It's only really a control problem, but does need a bit of thought when it comes to both the sensors needed and the control mechanism.  With the Sunamp PV, they chose to not control the heating element, but to allow that to accept whatever power was available from the excess PV diverter.  They then needed to ensure that the charge loop was maintained at around 65 to 75°C (IIRC) which meant sensing the temperature of the charge water flow, the flow rate of the charge water (using an ultrasonic flow sensor) and a variable speed circulating pump (looked to me to be a standard Grundfos one, not sure of the model).  The trick is then to control the flow rate so as to maintain a near-constant temperature in the charge loop, despite wide variations in power to the heating element.  Not too hard to do, but coping with the varying response time of the system would need some fine tuning, I suspect. 

 

The easiest way to get a working system might be to try and acquire the charging circuit and controls from a Sunamp PV...

[Barney12]

Just walked into my plant room and thought "its cool in here". Then realised both of my Sunamps are cool to the touch. RCBO's fine. 

So perhaps I wont go outside and do what I was intending to do and instead fault find these useless piles of shit gooo AGAIN.

??????????

 

[Barney12]

OK so thankfully that didn't take too long but REALLY? Can a technology really be this unreliable?

My red indicators (illegally fitted of course!) were not lit and my power meters weren't flashing so I know neither of them were drawing power. 

 

So rather than simply "bounce" them lets see whats going on behind the panels. Board has power but no demand light on. Check permanent feeds and immersions feeds (basic test but couldn't be bothered to go and get my meter). All good.

 

 

So clearly no demand for charge:

 

 

So now power cylce the permanent supply (They are switched independently you can see the switches either side) and TADA they both start demanding charge.

 

 

Of course there is no way of knowing when they stopped calling for charge. I'll get some idea once they've both fully charged as I can see how much power they consume. 

 

 

[Barney12]

On 14/04/2019 at 09:50, JSHarris said:

Just pulled the contactor out.  It's a Finder 22.22.8.230.4000 and it's definitely buggered (this is the thing: https://uk.farnell.com/finder/22-22-8-230-4000/relay-dpst-no-250vac-20a/dp/1169295).  Looks like it's been overheating slightly on the line in terminal, although all the screws were tight.  The closest I've got to this is a spare 20 A, DP, ABB contactor, rather than the 32 A ones I use in the car charge point.  ABB stuff tends to be a bit better than Finder stuff, IMHO, so having checked that the spec looks similar I'm off to fit the new one and see if that fixes things.

 

Jumping back to your thread. My controllers are relatively new (my third set!) and this is the relays in my units:

 

 

[Jeremy Harris]

As you know, the primary issue I've been having has been the controller periodically not calling for charge.  My fix has been to turn the controller off and on again to reset it, much as you've just done.

 

The slightly worrying thing is that your controllers look like the new ones that have the new power relay and, I thought, the new firmware to get around the failure to charge issue.  That's slightly worrying, as I have a new controller on it's way to me this week, that I suspect may be the same as yours.

 

Out of interest, do you know the model of controller you have?  I've been told that the new controller that's heading my way will have the B_100 firmware,  although I can't find the firmware version anywhere on our controller.

[Barney12]

1 minute ago, JSHarris said:

Out of interest, do you know the model of controller you have?  I've been told that the new controller that's heading my way will have the B_100 firmware,  although I can't find the firmware version anywhere on our controller.

 

Alas no. The only difference I could see from this set to the last was the relay type.

These controllers were delivered in December so there is a good chance yours will have later software. 

[Barney12]

On 22/04/2019 at 13:04, Barney12 said:

Of course there is no way of knowing when they stopped calling for charge. I'll get some idea once they've both fully charged as I can see how much power they consume. 

 

So they both consumed electricity and stopped accepting charge after my bounce as follows:

 

(readings from the meters)

 

Unit 1: 3kwh

Unit 2: 6kwh

 

This suggests that Unit 1 was at 75% and Unit 2 at 50% (Mine are 12kwh units). They should be demanding charge at c50%.

Whats really getting me to scratch my head is the units were cool, the pipework was cool, the plant room was cool. Clearly they were much more discharged than the figures would suggest. 

So are my units fully charging partially? There is no way of knowing as you've got no indication of level of charge.

 

Yet again the world of Sunamp leaves you largely in the dark!  

 

Edited April 23, 2019 by Barney12

[Jeremy Harris]

If you have the same firmware that we have, then the earliest that charge will start (assuming the controller is set to "50%") will be when around 40% discharged (60% charge remaining).  If the controller is set to "90%" then it should start to accept a charge when it has about 10% charge remaining.

 

The new firmware seems to improve the "50%" setting so that charging starts after around 15% has been used, so around 85% charge remaining.

 

[Barney12]

14 minutes ago, JSHarris said:

If you have the same firmware that we have, then the earliest that charge will start (assuming the controller is set to "50%") will be when around 40% discharged (60% charge remaining).  If the controller is set to "90%" then it should start to accept a charge when it has about 10% charge remaining.

 

The new firmware seems to improve the "50%" setting so that charging starts after around 15% has been used, so around 85% charge remaining.

 

 

Sorry, I'm forever typing that the wrong way round and getting confused! My units are now set to 50% like yours.

So much miss-information from Sunamp in the early stages has left my brain addled!  

 

I've edited my post. 

Edited April 23, 2019 by Barney12

[Barney12]

Following on from the above I'm going to revert to keeping a detailed log of demand and recording daily meter readings. 

Since the above readings I've taken one shower and there has been no other demand save for the hot water loop to the kitchen which has run for a few hours.

Its the only way I can get a sense of what is going on. 

 

Its OK though I've got nothing else better to do    

Edited April 23, 2019 by Barney12

[Ed Davies]

1 hour ago, Barney12 said:

Whats really getting me to scratch my head is the units were cool, the pipework was cool, the plant room was cool. Clearly they were much more discharged than the figures would suggest. 

 

Did you try cycling them again to see if they'd accept more charge?

[Barney12]

1 minute ago, Ed Davies said:

 

Did you try cycling them again to see if they'd accept more charge?

 

Yes. They flicked on and off pretty much straight away. 

[Jeremy Harris]

Bear in mind that they will be cool if the PCM is liquid, as the heat is released as it changes phase to solid.  They can sit charged and liquid for a long time (several days when I swapped out the old Sunamp PV).

[Barney12]

28 minutes ago, JSHarris said:

Bear in mind that they will be cool if the PCM is liquid, as the heat is released as it changes phase to solid.  They can sit charged and liquid for a long time (several days when I swapped out the old Sunamp PV).

 

Thats not my experience at all. The units are always warm to the touch and when charged the supply pipework is roasting hot between the two units. 

Ive assumed that’s because the kitchen hot water circulator pump (which switches on when the kitchen light comes on) and other demand keeps things hot?

Edited April 23, 2019 by Barney12

[Jeremy Harris]

12 minutes ago, Barney12 said:

 

Thats not my experience at all. The units are always warm to the touch and when charged the supply pipework is roasting hot between the two units. 

Ive assumed that’s because the kitchen hot water circulator pump (which switches on when the kitchen light comes on) and other demand keeps things hot?

 

It may well be that your recirculation system is causing the PCM to change phase, I think.  Our unit stays pretty cool, the case never feels warm to the touch, and the only place I can feel heat is at the mixer valve (all the other pipes are lagged).

[Barney12]

17 hours ago, Barney12 said:

Following on from the above I'm going to revert to keeping a detailed log of demand and recording daily meter readings. 

Since the above readings I've taken one shower and there has been no other demand save for the hot water loop to the kitchen which has run for a few hours.

Its the only way I can get a sense of what is going on. 

 

Its OK though I've got nothing else better to do    

 

OK, so I went down first thing this morning and took another set of readings. In that time only two things had any demand on the Sunamps:

 

1 x 5 minute shower.

Aprox 2 hours of the kitchen hot water loop (c12m of 15MM pipe all very well lagged)

 

Unit 1: 4.5

Unit 2: 4

 

That's clearly double what my previous logs have shown for that level of usage.

 

I think all I'm really doing is proving what we already know; the controller (and measurement) system is less than perfect!

 

 

Edited April 24, 2019 by Barney12

[oranjeboom]

And here I was about to get Sunamp to deliver my 2x 12Kw eDual units....looks like I may have to either delay again or consider asking for a refund!

 

Intrigued whether you are able to diagnose your issues @Barney12 and hopefully Jeremy @JSHarris has no further tinkering to do!

[willbish]

Has been very quiet on the Sunamp front for a while. I take that as a good sign

 

I've finally received a response back from Sunamp, which Ive pasted below. I asked them would any mechanical or software changes be made to my Sunamp units, which are currently sat in Sunamp HQ, before being delivered

 

@JSHarris Did you receive a new controller? How is it performing?

 

 

I do apologise for the delay however I managed to track down our Technical Director who has responded as follows:

 

My comments:

 

As part continuous process of product improvement, we have improved the heat transfer rate between the heating element and the heat battery heat store. The power input is managed by the controller by cycling the heater on and off during the charging phase. With the above improvement, the cycling of the heater is now rarely required and therefore this has allowed us to increase the power input during heating from cold phase of charging the battery.

 

In addition to the above,

1. charging control algorithms have been refined and the charging is now re-enabled as soon as a small quantity of water has been run off, OR when the heat battery has lost some heat through standing losses after several hours.
2. ther compatibility problems with some makes of diversion controllers have been resolved.

 

Your unit will have an updated controller.

 

 

Kind regards

 

 

 

[Barney12]

I’ve heard nothing from Sunamp. Radio silence and the ball is in their court.

[Jeremy Harris]

12 hours ago, willbish said:

@JSHarris Did you receive a new controller? How is it performing?

 

 

Yes, recently installed it, together with a new sensor string.  They offered to replace the entire Sunamp, as the newer version has some improvements, including an additional temperature sensor, but the logistics of getting the old one out and down the stairs, and the new one in and up the stairs (they weigh about 150kg) meant that I refused their offer and just fitted the new controller.

 

It's early days, in that we've had lots of excess PV generation since I swapped units over, so I've not been able to do a 100% test of all the cases where the old controller might fail to start a charge, but so far it does seem that the charge threshold has been reduced. 

 

One major snag is that I've been prohibited from adding back my indicator light - Sunamp are adamant that this should not be fitted (can't see why, there's no technical reason not to).  This means I have to run the controller with the cover removed (exposing live terminals...) as that's the only way to check whether or not the relay is on (an LED on the PCB indicates this).

 

The absence of any external indication as to what the unit is doing remains a major problem, as for those of us who have been caught out by having the unit fail to charge, with no hot water, not having the reassurance of the unit charging is a major snag.