Surge protection for fridge

The failure rate of domestic surge protectors possibly exceeds the failure rate of what you are trying to protect.

What are the thoughts on a whole house SPD fitted in the CU?

no

no There is an excess of bs talked about 'surges'. In >99.9% of cases 'surge absorbers' just take people's money & give them a fire risk.

I make a point of actively avoiding them in extension leads.

There could be some benefit in having a whole house type if you have long overhead power lines which are prone to induced voltage spikes from lightning. However, if there is a nearby lightning strike nothing will protect you.

The power supplies in most electronic equipment will tolerate significant spikes and surges for short periods. There will typically be a 400Vdc capacitor after the bridge rectifier in a switching power supply. This will usually tolerate 20% overload for short periods. At 250V ac mains input the capacitor will be charged to about 350V dc, but it will generally be able to tolerate over 500V for short periods.

John

The old refrigerators were very robust.

They could regularly last forty years. Without a bit of preventive maintenance.

Never needed to be unplugged during a lightning storm.

It's the newer refrigerators, they don't have the track record, to be drawing any conclusions.

A modern refrigerator, even a cheap one, can have a CPU and low voltage DC inside. Whereas the old refrigerators followed the "hunk of iron" paradigm. (Timer motor and the odd relay, for sequencing.)

One of the Korean brands of modern fridge, for pentane/butane it uses a variable speed compressor. It's hard to say what the consequences for reliability might be, on one of those. Compressor could be DC powered. Might not be a scroll compressor, but perhaps a piston compressor and a brushless DC motor. The power side exposed to mains, would not be the same as the old refrigerators.

Since the new refrigerators tend to have metal covers so you can't see anything, you can't even roll the mother out and poke around. And you never know how that stupid cover, is tied to the refrigerant piping (thermal tape???).

Paul

We now fit them on a CU swap/new build/rewire as standard.

Options are available to downgrade.

Anything is possible but since fridges and freezers are inductive loads there is more chance of the protection failing catastrophically.

Filament bulbs tend to react very badly to intermittent restarts of mains with a few over voltage spikes thrown in. It bounces off inductors although it might blow surge protection devices and filter capacitors.

I give you Russ Andrew. If you are that mission critical use a whole-house UPS.

Your counterpart that rewired our house also fitted one, it was optional, but I opted for it

I've removed the RCD from our CU and replaced all the previously RCD protected MCBs with RCBOs. Mainly because we suffered occasional nuisance trips, due to all the electronics in this house giving quite a high base leakage rate.

I'm gradually replacing the previously unprotected MCBs with RCBOs (lighting, etc.). We are looking at adding an EV charger circuit soon too.

While I was at all these changes, I thought that I may add an SPD - especially as removal of the RCD has left more spare ways in the CU and SPDs are not too pricey.

As they have thermal inertia, I'm not clear how that could be ?

I'd expect the fridge to cope.

The MOVs in an SPD protect against over voltage, if there's any surge following a power cut, it's likely to be high current when numerous capacitors and compressors are all re-powered, which would be more likely to cause low voltage ... maybe there'd be an overshoot correction of the sag?

They normally die on cold inrush current. In short being switched on

Surge absorbers won't help them any.