SunAmp : Snog, Marry, Avoid?

[Jeremy Harris]

Good news!

 

Fitting an ABB 20.20 contactor has restored normal service, and the unit is now charging up again.  I'd like to take the old Finder contactor apart, to see how it's failed, but fully intend to get Sunamp to sort this, as I don't see why I should have to put a replacement £30 contactor into their 6 month old box.

 

9 minutes ago, scottishjohn said:

one might wonder why they are not using solid single strand wiring in that sort of installation -should not be any vibration to worry about and could be bent to shape and could  be clamped .

we know the answer --its probably cheaper cos you can ,If i remember correctly, use thinner multi stranded wire for same current load,as current passes along the surface of wire

 

It's normal to use stranded equipment wire in stuff like this, makes it a lot easier to wire up.  However, it's also good practice to fit insulated wire ferrules at screw terminations (should be made mandatory in my view).  This is what happens when people choose to wire up fine stranded wire without using ferrules (look at the end of the line connection):

 

[ProDave]

I have always regarded Finder as very much budget stuff, nowhere in the league of ABB, Telemech etc.

 

Glad you have sorted it without pulling your plant room to bits.  Next time (if there is a next time) do an ohms check on the outgoing pair with the contactor open.

 

[Jeremy Harris]

Just now, ProDave said:

I have always regarded Finder as very much budget stuff, nowhere in the league of ABB, Telemech etc.

 

Me too.  I tend to always use decent brand name stuff where I don't want failures (or fires...).  This is the new ABB contactor in and working (excuse the untidy red wires, they run to my add-on neon indicator to show that the contactor is on):

 

[Russdl]

13 minutes ago, JSHarris said:

Fitting an ABB 20.20 contactor has restored normal service, and the unit is now charging up again

 

Well done Jeremy for the quick fix.

 

It's really reassuring to know that when I get my Sunamp(s) that 'Sunamp Repairman' lives not too far away ?

Edited April 14, 2019 by Russdl

[Jeremy Harris]

I'll make sure I keep a stock of spares...

 

It's damned lucky that I happened to have that new ABB ESB 20.20 contactor sat in my "may come in handy" box.  It's a spare for the contactor that switches our water pump on and off, so I'll now have to go and buy another one to use as a spare.

[Jeremy Harris]

1 hour ago, Onoff said:

It's nothing here that can be temporarily bridged to see if it is the overheat stat?

 

 

 

 

Not sure what that controller is for, TBH, as it looks nothing like the controller for the Sunamp UniQ we have.  It looks as if it can control a whole heating and hot water system to me, which is interesting.  The controller we have is a lot simpler, and just has three temperature sensors inside the heat battery, a small board with the control electronics, and a contactor on the DIN rail with all the other terminals.

 

1 hour ago, Onoff said:

 

Are these the ones that like a water softener feeding them or they scale up?

 

I think the old Sunamp PV was fine on hard water, as they were initially concerned that softened water might cause a problem, which is why they wanted our old unit back, together with a sample of our water, to cut the thing open and see how it looked inside, after nearly three years of use.

 

We now have hot water back, thankfully.  There's enough excess PV generation to start the Sunamp charging, and the water's reasonably warm.  I'll definitely keep an eye on the contactor for a while, and might add another neon indicator to show when there's power going to the Sunamp heating element.  The lack of any sort of status display on the Sunamp UniQ series is a real PITA, as you have no easy way to see if the thing is working properly.  The Sunamp PV was great, as it had four status LEDs on the side, so you could see at a glance what it was doing.  Not fitting any sort of status indication at all to the UniQ range seems barking mad to me.

[ProDave]

So the brief for the new controls engineer they appoint:

 

Sort out the control system so it accepts charge properly.

Undo the "value engineering" to replace failed parts with a different make, to make the product reliable.

Spend a few pence per unit on bootlace ferrules.

Add some basic status monitoring to the controller.

Properly document all features like the location of an overheat resettable trip.

 

[oranjeboom]

3 minutes ago, JSHarris said:

might add another neon indicator to show when there's power going to the Sunamp heating element.

If you do go down that path, could you take a series of pics that non-engineers like me could follow? Would indeed be useful to know what the thing is doing rather than just turning on the hot tap and seeing whether the thing's been charging or not. Be good to be able to self-diagnose the unit without having to call Sunamp each time. The last thing I want to do is un-plumb and manhandle 400kg to get access or even send the units back. Shame there's no app or even a USB port you can check the status with.

[Jeremy Harris]

I can easily do this, but I'll hang on until I get the new controller from Sunamp (they are sending out new controllers to some customers, it seems, including us).  As I understand it, the new controllers they are sending out still have no form of external indicators.

 

What I think I'll do is fit a couple of indicators to a blank face plate, with labels, and a cable back to the Sunamp controller.  I reckon that having three indicators might be enough, one to show that the power is on, one to show if the contactor is getting an energise signal and one to show when power is on at the contactor load side.  It might be OK with just two indicators, an incoming power indicator and a heating element power indicator.

[Barney12]

1 hour ago, JSHarris said:

Me too.  I tend to always use decent brand name stuff where I don't want failures (or fires...).  This is the new ABB contactor in and working (excuse the untidy red wires, they run to my add-on neon indicator to show that the contactor is on):

 

Why do I fear that Sunamp will blame your red neon status fix on the contractor failure. After all based on your previous post they claim it effects operation of the controller????

[Jeremy Harris]

Just now, Barney12 said:

 

Why do I fear that Sunamp will blame your red neon status fix on the contractor failure. After all based on your previous post they claim it effects operation of the controller????

 

They will find themselves in one heck of an argument if they do!

 

Given that a contactor has to provide isolation between the coil and the power terminals (the Finder one they fitted is is specced to 4 kV between coil and contacts) there is no way that anything connected to the coil terminals could possibly affect the contacts.

[Onoff]

30 minutes ago, JSHarris said:

Not sure what that controller is for

 

The manual that screen shot came from. Page 42:

 

pdf2040.pdf

 

What interested me was the pc connection option. You and a few others on here would have a field day with the source code!

[Onoff]

5 minutes ago, JSHarris said:

 

They will find themselves in one heck of an argument if they do!

 

Given that a contactor has to provide isolation between the coil and the power terminals (the Finder one they fitted is is specced to 4 kV between coil and contacts) there is no way that anything connected to the coil terminals could possibly affect the contacts.

 

Could the resistance of the neon across A1/A2 have affected the coils ability to bring the contactor in properly? 

 

Is there a spare set of NO contacts on that ABB relay. I'd use them to feed the neon.

[Jeremy Harris]

4 minutes ago, Onoff said:

 

The manual that screen shot came from. Page 42:

 

pdf2040.pdf

 

What interested me was the pc connection option. You and a few others on here would have a field day with the source code!

 

Thanks!

 

This looks to be the controller that Andy Trewin was talking about last time I spoke to him.  I think he has this controller, as he was telling me that he can get any information he wants from it.  He no longer works for Sunamp, so he didn't know anything about the controller we have, or why Sunamp seem to have changed the design. 

 

I've been in touch with others who have Sunamps and Andy Trewin is the only one I know of that has a more complex controller.

 

7 minutes ago, Onoff said:

 

Could the resistance of the neon across A1/A2 have affected the coils ability to bring the contactor in properly? 

 

Is there a spare set of NO contacts on that ABB relay. I'd use them to feed the neon.

 

It's hard to see how.  The contactor is switched by a relay (one of these: https://uk.farnell.com/te-connectivity-schrack/rz03-1a4-d012/power-relay-spst-no-12vdc-16a/dp/1844686 ) that switches mains straight from the always-on supply, and that relay is rated at 16 A, so an additional current of a bit under 1 mA to supply a neon indicator isn't going to have any impact.  The relay on the controller circuit board seems to be massively over-rated for something that only switches a contactor on and off, I'm not sure why they chose to use a 16 A rated relay when they are only switching about 22 mA.

[Ed Davies]

1 hour ago, scottishjohn said:

If i remember correctly, use thinner multi stranded wire for same current load,as current passes along the surface of wire

 

You're thinking of skin effect which is negligible at 50 Hz for any domestic-size wiring. It could matter for small cables at higher frequencies and for things like the wiring in the grid or substations at 50 Hz.

 

1 hour ago, scottishjohn said:

its just you don't, get dead if you touch wrong thing on car - 

 

Indeed, but you can lose fingers, etc. YouTube videos of people handling off-grid or boat batteries while wearing rings or metal watch straps really make me cringe. I know of a case of somebody having a finger burned off as a result of getting their ring welded across a 5 volt power supply.

[Onoff]

3 minutes ago, JSHarris said:

 

Thanks!

 

This looks to be the controller that Andy Trewin was talking about last time I spoke to him.  I think he has this controller, as he was telling me that he can get any information he wants from it.  He no longer works for Sunamp, so he didn't know anything about the controller we have, or why Sunamp seem to have changed the design. 

 

I've been in touch with others who have Sunamps and Andy Trewin is the only one I know of that has a more complex controller.

 

 

It's hard to see how.  The contactor is switched by a relay (one of these: https://uk.farnell.com/te-connectivity-schrack/rz03-1a4-d012/power-relay-spst-no-12vdc-16a/dp/1844686 ) that switches mains straight from the always-on supply, and that relay is rated at 16 A, so an additional current of a bit under 1 mA to supply a neon indicator isn't going to have any impact.  The relay on the controller circuit board seems to be massively over-rated for something that only switches a contactor on and off, I'm not sure why they chose to use a 16 A rated relay when they are only switching about 22 mA.

 

I just wondered if the Finder contactor was priced down to the bone then the (10K?, more?) neon resistance across the coil might have seen it not pulling in properly. Open it up and look at the contact faces?

[Jeremy Harris]

1 minute ago, Onoff said:

 

I just wondered if the Finder contactor was priced down to the bone then the (10K?, more?) neon resistance across the coil might have seen it not pulling in properly. Open it up and look at the contact faces?

 

The neon series resistance is about 330k, but will appear higher, as the neon will be running at around 60 VAC or so, so the current drawn by the indicator will be well under 1 mA (I might measure it later).

 

The current drawn by the coil is about 22 mA, and has a tolerance of around +/-5%, so, depending on the exact part fitted, it could vary from just under 21 mA to just over 23 mA.  That's more variation than there would be from adding a neon indicator.  Anyway, the source supply is a fused 3 A supply switched by a 16 A relay, so there's never going to be any measurable difference in the voltage across the contactor coil, just from that connection being loaded by another half milliamp or so.

[Jeremy Harris]

Just been testing the defective Finder contactor on the bench.  It seems to have broken mechanically, as when the coil energises the over-centre mechanism tries to move, makes a loud clunk, but jams.  There's a mechanically driven indicator on the top, and this barely moves, whereas it's supposed to flip and show a red flag to show that the contactor has energised.  Also, it rattles a lot, as if there are loose bits floating around inside.  I'm tempted to take it apart, but that would mean drilling out two rivets, and I really want to get this replaced by Sunamp, given that the ABB one I've just fitted cost ~£30.

[ProDave]

26 minutes ago, JSHarris said:

Just been testing the defective Finder contactor on the bench.  It seems to have broken mechanically, as when the coil energises the over-centre mechanism tries to move, makes a loud clunk, but jams.  There's a mechanically driven indicator on the top, and this barely moves, whereas it's supposed to flip and show a red flag to show that the contactor has energised.  Also, it rattles a lot, as if there are loose bits floating around inside.  I'm tempted to take it apart, but that would mean drilling out two rivets, and I really want to get this replaced by Sunamp, given that the ABB one I've just fitted cost ~£30.

I bet that is a "value engineered" plastic part that has snapped.  Reminds me of a well know make of bathroom fan heater where the pull cord operates on a simple see saw lever that pushes up on a switch when you pull the cord down.  It is a grossly under engineered bit of plastic.  The one in our static caravan snapped. It took me about 5 minutes to make a replacement out of a bit of steel sheet with a hacksaw and a file. Not pretty but a LOT stronger than the inadequate original.

 

The strange thing is, I have replaced several of these heaters with a new identical one with the same silly plastic lever.  Why don't people learn?  my reaction when something like that breaks is I would actively seek a different product rather than reward that manufacturer for using a defective part.

[Jeremy Harris]

4 minutes ago, ProDave said:

I bet that is a "value engineered" plastic part that has snapped.  Reminds me of a well know make of bathroom fan heater where the pull cord operates on a simple see saw lever that pushes up on a switch when you pull the cord down.  It is a grossly under engineered bit of plastic.  The one in our static caravan snapped. It took me about 5 minutes to make a replacement out of a bit of steel sheet with a hacksaw and a file. Not pretty but a LOT stronger than the inadequate original.

 

The strange thing is, I have replaced several of these heaters with a new identical one with the same silly plastic lever.  Why don't people learn?  my reaction when something like that breaks is I would actively seek a different product rather than reward that manufacturer for using a defective part.

 

I suspect you're right.  The action of the Finder contactor was always a bit violent, in that from new it made a hell of a clunk as it operated, enough to wake the dead.  I've got a four pole 20 A contactor running a couple of socket radials in my workshop (I have E stops around the place to kill the supplies) and even that doesn't make anywhere near as much noise as the Finder one used to.  The ABB one I've just fitted is a fair bit quieter, too.  Makes me wonder if the Finder may have had an incipient mechanical defect from new, given the amount of noise it made.

[jack]

2 hours ago, Ed Davies said:

You're thinking of skin effect which is negligible at 50 Hz for any domestic-size wiring. It could matter for small cables at higher frequencies and for things like the wiring in the grid or substations at 50 Hz.

 

Ah yes, the skin effect. Beloved pseudo-scientific explanation of audiophiles who believe spending thousands on interconnects or (worse) power cables with the same resistance, capacitance and inductance as the components they're replacing will somehow "lift a veil" off the sound of your system. 

 

From memory, the contribution of the skin effect even at thousands of kHz is negligible.

[scottishjohn]

6 hours ago, Ed Davies said:

 

You're thinking of skin effect which is negligible at 50 Hz for any domestic-size wiring. It could matter for small cables at higher frequencies and for things like the wiring in the grid or substations at 50 Hz.

 

 

Indeed, but you can lose fingers, etc. YouTube videos of people handling off-grid or boat batteries while wearing rings or metal watch straps really make me cringe. I know of a case of somebody having a finger burned off as a result of getting their ring welded across a 5 volt power supply.

yes low voltage and high amperage will still hurt you .

when i was young and foolish i was working on a car with a wrist watch and it shorted down on the battery terminal when trying to get to something hidden -- took a few weeks for the skin to grow again as it took a lots of layers off before i could get my hand out  and was very painful for a long time  .

watch kept working 

 

.

[Pete]

How are you doing at understanding this latest fiasco concerning Sunamp @AnonymousBosch? The more this goes on I wish I had installed some ducting for gas when | put my utilities in! My concern is that us mere mortals cannot understand or even comprehend fixing or trying to make this latest Sunamp work when it goes wrong and from what it looks like this is becoming a regular thing. Not impressed at all.

[ToughButterCup]

8 hours ago, Pete said:

How are you doing at understanding this latest fiasco concerning Sunamp @AnonymousBosch? 

 

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. 

[Jeremy Harris]

Worth noting that this contactor failure looks to be an isolated event, as I've not heard of any other contactor failures.  However, the contactor used in our controller has been changed to a very different relay in the newer controllers.  Whether this is due to any concern about long term reliability or not I don't know.  My instinct is that the change may have been made to reduce noise, as the contactor originally fitted did make a very loud clunk as it operated.