Midea 11kW and flickering LED lights

[kieranS]

Hi all, 

 

First time post 

 

I just had a new Midea 11kW heat pump installed as part of a full house renovation. 

 

We have had all new electrics and a new MCB board fitted.

 

It seems that when the ASHP is running at higher loads the LED lights in the kitchen, utility and hall way all flicker ever so so slightly. 

 

During lower load operation this is not a problem.  We have other high load appliances in the house like an induction range cooker and there is no flicker when this is working.  My home electrician is currently on site and has tested the mains voltage and the supply seems fine. We have also swapped the breaker and checked all the wiring for the ASHP and everything seems fine.

 

I have googled this problem and there are a few cases it seems but mainly in the US.

 

The ASHP installer is coming out over the next couple but has never experienced this sort of thing before.

 

Has anyone else had experience of this type of issue? 

 

 

Thanks

 

Kieran

[SteamyTea]

5 minutes ago, kieranS said:

seems that when the ASHP is running at higher loads the LED lights in the kitchen, utility and hall way all flicker ever so so slightly

Flicker is a bit of a vague term.

Do you mean they dim a bit for a second or two, or pulsate at a fixed frequency all the time the ASHP is running at full chat?

The causes could be as simple as terminals needing a re-tighten, to a larger supply cable, better 'drivers' on the light circuit, or even a better motor controller in the ASHP.

[kieranS]

Hi steamyTea, 

 

Thanks for response - the lights do not appear to dim but pulsate at a fixed frequency as you say. Almost as if the are operating at a lower frequency visible to the naked eye.

 

The lights in the kitchen and utility are spotlights all the same - probably around 20 of them.  In the hallway they are bulbs hanging down from the ceiling.

 

MCB connections have been fully checked and are secure.

[ProDave]

I have exactly this with my LG ASHP but only on start up, not at full running.

 

It will be the variable speed drive in the inverter putting a varying load on the supply and hence dipping the voltage rapidly.  It is precicely this that worries DNO's as they don't want your ASHP flickering next doors lights.

 

It would be interresting to hear from the electrician the loop Ze of the supply and Zs of the ASHP circuit.

 

In our case it is only the lights in the utility room affected so we ignore it.  A different make of LED lamp elsewhere is not affected, so first instance I would buy a few of different makes of LED lamp, and when you find one not affected, buy a job lot of them.

[kieranS]

Thanks for the feedback ProDave - glad to hear I am not the only one.

Luckily we are out on our own so no neighbours to annoy. 

 

I will ask the ASHP electrician when he arrives to test the impedance. 

 

If it something like the bulbs it will be a relief - its one of those problems which you can imagine it will be difficult to find the root cause!

[ProDave]

If you are out in the sticks your supply impedance might be a bit high if you are not close to the nearest transformer.

[kieranS]

We are close to a housing estate and village but there are a few fields in-between.

 

If we do have high impedance does this mean we would be stuck with the problem unless we get a new transformer installed?

Edited March 6, 2023 by kieranS

[kieranS]

Just to update on this - I tried a number of different LED bulbs and found one that works without the flickering.  

 

Original bulbs were not cheap (Integral) but upgrading to Philips sorted the problem.  ASHP installer had no other suggestions for the issue.

 

Still overall very pleased with the Midea😀

[HughF]

I have the exact same problem when running inductive loads (inverter charger doing a battery charge) on my generator, as you have found out, it’s down to the LED drivers in the bulbs.