ASHP shutdown on over current

[JohnMo]

Woke up this morning and ASHP was off. Screen off etc. cycled the isolation switch and it came back to life. Got on with doing DHW. Looking at the history it had a

"Overcurrent PFC inverter 1". Prior to shutdown it had been doing some floor heating and was 15 mins into doing a DHW heat cycle.

 

The wind speed last night was high 60mph and very gusty. So not sure it got hit with a blast of wind or there is an underlying issue. 

 

Anyone had similar or have any thoughts what to check?

[Michael_S]

Could it relate to over voltage in the mains?

We have a wifi enabled RCBO on our HP so can see real time the voltage, current, watts, leakage, cable temp etc.

[MikeSharp01]

1 hour ago, JohnMo said:

Overcurrent PFC inverter 1

I think of PFC as Power Factor Correction assuming this the possible reasons are all over the place but as @Michael_S says could be a mains glitch that took it out of range. If so it probably will not recurr but if it does you will need to dig deeper loose wire or something that causes the motor a problem which I suppose a high speed gust of wind right up its axis might well do.

 

[JohnMo]

Just had a look at what info I can get. Unless there was a blip, but battery and inverter didn't see anything strange or pick up on it.

 

So circulation pump went off at 05:39 (grid volts 241.6, 50Hz)then restarted 05:40, at 05:46 it tried to start DHW heating again and everything seems to have tripped at 05:47 (grid volts 246V)

[Alan Ambrose]

Btw those wifi devices are partly cute but note that Mike of mikeselectricstuff thinks they’re quite dodgy:

 

 

[sharpener]

1 hour ago, Michael_S said:

Could it relate to over voltage in the mains?

 

Plausible. When it is gusty the power lines will dance all over the place and frequently short, the DNO will usually succeed in containing the effects but you may get spikes on the mains.

 

PFC could well be power factor correction, there might be a capacitor across the input for this. They are usually self-healing but a transient overvoltage might have caused some temporary damage which registered as overcurrent.

 

Similarly we had a glitch yesterday, the lights dipped for 1/2 second and I feared it would upset the clock on the cooker which is sensitive to these things but it didn't. Almost immediately there was a lighting flash and thunderclap so the electric storm was likely the underlying cause.

[-rick-]

2 hours ago, JohnMo said:

"Overcurrent PFC inverter 1".

 

Concerning. Definitely possible its a fluke but if it recurs I'd guess something on the control board is faulty and that will be a pain to investigate. I'm just a hobbyist but I'm a little doubtful an overvoltage condition would cause a PFC overcurrent error as the PFC circuit should self regulate whatever the voltage. About the easiest to fix 'electronics' issue that might cause this is bad capacitors but the input capacitors are generally fairly robust. Having said that, your HP is a Chinese up and coming brand rather than big name so maybe they cheaped out there.

 

Edit context: The most common PFC circuits work by boosting the voltage from the incoming supply to around 380-400V DC which is then used by follow on circuits. The boost works with an awareness of power factor so it draws more current at the peak voltage of the mains cycle and much less at the minimum voltage. AFAIK it will draw more current in an undervoltage situation, but it would have to be under by a lot I would have thought, ie, a brown out.

Edited Sunday at 18:33 by -rick-

[JohnMo]

41 minutes ago, -rick- said:

your HP is a Chinese

It's actually made in Italy. But definitely not big here.

[-rick-]

15 minutes ago, JohnMo said:

It's actually made in Italy. But definitely not big here.

 

Oh sorry. Was thinking it was the Chongfu one. Less likely an easy fix then if it's not a fluke.

[dpmiller]

Had something similar a couple of months back on our Coolenergy unit- one of the three spade connectors on top if the compressor had loosened and burnt. The codes on the Carel unit were for starting fail and overcurrent which had me fearing the worst- shorted windings. Might be worth a peek under the plastic cover atop the compressor...

[JohnMo]

8 minutes ago, dpmiller said:

Had something similar a couple of months back on our Coolenergy unit- one of the three spade connectors on top if the compressor had loosened and burnt. The codes on the Carel unit were for starting fail and overcurrent which had me fearing the worst- shorted windings. Might be worth a peek under the plastic cover atop the compressor...

Good call

[Temp]

12 hours ago, dpmiller said:

Had something similar a couple of months back on our Coolenergy unit- one of the three spade connectors on top if the compressor had loosened and burnt. The codes on the Carel unit were for starting fail and overcurrent which had me fearing the worst- shorted windings. Might be worth a peek under the plastic cover atop the compressor...

 

Apparently there are heat tolerant versions of spade connectors used in ovens. I thought it was just the insulation that was heat tolerant but some say it the connector itself.

[Nickfromwales]

36 minutes ago, Temp said:

 

Apparently there are heat tolerant versions of spade connectors used in ovens. I thought it was just the insulation that was heat tolerant but some say it the connector itself.

Yup.
 

I used to overhaul galley equipment on RFA vessels, and the connectors were quite specific; using a metal that tolerated the heat / cool cycling that these things are subjected to during normal service.

 

A high temp insulation was used on the terminals too.

[HughF]

On 05/10/2025 at 21:40, dpmiller said:

Had something similar a couple of months back on our Coolenergy unit- one of the three spade connectors on top if the compressor had loosened and burnt. The codes on the Carel unit were for starting fail and overcurrent which had me fearing the worst- shorted windings. Might be worth a peek under the plastic cover atop the compressor...

Interesting, I’ll check mine next time I’m on-site. Been running faultlessly for 2 years now, right about the time it’ll go wrong 😂

[Wil]

The connectors on my CE unit burnt too causing all sorts of fun (including a RTB). Upgraded connectors solved all woes.