immersun repair -no.3

[Marcus]

Hi Matt,
It does sound like the 1st immersun repair i did. IIRC it was the failure of the big black 5uF on the input side that causes the varistor and triac to destruct.

From memory i got the replacement from one of the big suppliers (farnell/rs/mouser/digikey) - i definitely ordered just one - but it'll have to wait til i fire up the computer this evening for me to see what i ordered and from where...

Farnell, completely forgot about them! Think I have found it, typical the postage costs more than the part!

Should I replace both the 5uf capacitors? or just the one that has spat all it's contents out??

Thanks.

Personally I would replace all the electrolytics.

At the risk of being pedantic i don't think it's an electrolytic.

It's up to you if you replace the other; the additional cost is small c.f. the postage as you know, but i didn't bother myself as the other still read 5.0uF and showed no sigs of distress. The 5uF on the input side is subject to 230v a.c. all the time, whereas the other is on the pwm output and only sees voltage whist power is diverting to the load, and even then only sees a.c. voltage proportional to the square root of the diverted power - i.e. it only sees the full 230v a.c. when the immersun is diverting 'flat out' to the load.

[Fintray]

Farnell, completely forgot about them! Think I have found it, typical the postage costs more than the part!

Should I replace both the 5uf capacitors? or just the one that has spat all it's contents out??

Thanks.

Personally I would replace all the electrolytics.

At the risk of being pedantic i don't think it's an electrolytic.

It's up to you if you replace the other; the additional cost is small c.f. the postage as you know, but i didn't bother myself as the other still read 5.0uF and showed no sigs of distress. The 5uF on the input side is subject to 230v a.c. all the time, whereas the other is on the pwm output and only sees voltage whist power is diverting to the load, and even then only sees a.c. voltage proportional to the square root of the diverted power - i.e. it only sees the full 230v a.c. when the immersun is diverting 'flat out' to the load.

Sorry I just thought it was after the description of it self destructing.

[MattWolf]

It lives!!

Well, it hasn't let the magic smoke escape just yet.

Replaced the 5uf cap nearest the heat sinks along with the triac and varistor.

Only tried a very short boost but it "sounds" better, after my first repair there was a buzz as it started to increase the power which quickly went away as the power increased and the same again as it decreased. This time, silent.

Will get it fitted into a test rig comprising of an burko boiler and run it for a few hours to stress test it before I start sourcing hot water tanks.

Thanks for everyone's help.
Matt.

[Fintray]

Success, that's good to hear.

[Tinbum]

Anyone come across this one?

Nothing connected to Heater2 terminals or any other than power.

I suspect its showing heater 2 as the relay defaults to this one.

[Marcus]

I did see this during the immersun #2 repair: trying to remember...

you are correct that it 'sees' heater ouput 2 first during the selftest hence it stops there.

Ok: are you connecting it to a 'noisy' supply? Have you got it powered without an earth connection?

The reason i ask is that when i saw it it turned out to be a bit of a red-herring, and not a fault as such:-

The voltage feedback for the output uses an opto-isolator and a resistor/ capacitor voltage divider. In the immersun #2 case the 0v (neutral) and vout (diverter live out) for the feedback circuit were taken from opposite sides of a common mode choke.

The high frequency ~20kHz noise on the supply from the powerjack inverter would pass through the various filter caps between L & N and L& E (and N & E if you don't make the earth connection) and through the capacitance part of the voltage divider to generate a spurious voltage reading on the output.

Of course the simplest explanation: if the immersun is faulty and is passing voltage through to the output during the selftest when it shouldn't be.

[Tinbum]

Ok: are you connecting it to a 'noisy' supply? Have you got it powered without an earth connection?

Of course the simplest explanation: if the immersun is faulty and is passing voltage through to the output during the selftest when it shouldn't be.

I had a couple to repair, this one looked to just need new terminal blocks on the grid feed, which I did. It does look to be a fairly early version. The other one powered up fine with no faults after repair so don't think it's the supply. Earth is connected.

I can't see anything on the pcb to arc. I did clean the pcb as it was disgusting- flux everywhere. Reminded me of a Chinese inverter that came with a wind turbine i bought. That looked as if it had been soldered up by a child and even the fuse holder had a link wire between each end, you could have run it without even putting a fuse in it..

[Marcus]

Ok, but of the three immersuns I've had here, only one had an issue with my noisy supply - the other two were wired differently.

[Tinbum]

Ok, but of the three immersuns I've had here, only one had an issue with my noisy supply - the other two were wired differently.

That's interesting perhaps that's why the design changed. Thanks.

[Grasmere5]

Apologies for posting this on your discussion as I’m new and can’t find the method to create a new post concerning my Immersun fault and how it was resolved, and I’m hoping you could post this for me for others to see, I emailed Immersun with my issue and this is how it was resolved

Hello I hope you could advise
The unit is not starting up further than the words saying Immersun Loader, is there anything that I can check or buttons to press to reset and is there a repair service please?

Thanks for your enquiry. Please try a full reset on the Immersun unit using the exact procedure below:

Firstly cool the water in your hot water cylinder to well below thermostat temperature and ensure it is not being heated by any external heating sources (e.g. gas boiler) during this procedure but do not isolate the immersion heater. Turn off power to the Immersun unit. Wait 5 minutes then hold down the CROSS button whilst powering up. Do not release CROSS button until you see 'Force Normal Run' on the display.

Once you have reached the Home screen go immediately to Menu -> Advanced Settings -> Passcode 0000 -> Factory Reset -> Tick 'RESET CONFIG' & Tick 'RESET IMMERLINK' and the select Execute. After reset the unit will go through initial setup procedure, for this please ensure the correct option is selected for your sensor type:

Sensor type options:
WIRED = Your CT clamp is wired to your main IMMERSUN unit.
RADIO = Your CT clamp is wired to a smaller Wireless Sensor unit that communicates wirelessly with your main IMMERSUN unit.
SLAVE = You are using multiple IMMERSUN units linked together and this unit is not the primary unit.

Note: If your Immersun display freezes or if an Error message occurs during the above process then please try pushing the CROSS or TICK buttons on your IMMERSUN to see if it responds or allows you to navigate away from the Error message. If this fails then you will need to repeat the reset prodcedure again from the beginning and proceed through these steps much more quickly.

If you see "Water Hot", "Error 3 Heater not detected" or "Error 8 Load short Circuit" after completing the above steps then this indicates there may be an issue related to the output (your immersion heater, thermostat or heater cable and connection integrity), it is strongly recommended to have these external parts checked for faults by a domestic electrician. Please also refer back to the original wiring diagram in installation manual, if you believe the IMMERSUN may have been wired incorrectly please call us on 01908 101 955 to help troubleshoot.

Kind Regards,
Immersun Support

Absolute hats off to you mate, this is exactly the issue I had having just come back off holiday,
could not get past the Immersun Loader screen. Sent a ticket to Immersun support but meanwhile I found this post, followed it and perfect results. Just had to reset heater type and boost times - all ok