I have noticed that most of the surge protectors that manufactured in Israel and israelis brands that made in China (Hyundai)(Especially the ones for freezers, refrigerators and air conditioners), have a bulit in 4 mins delay, while surge protectors from foregin countries (Which aren't China) haven't this function.
Are in your country, are also sold, surge protectors with 4 mins delay, or these surge protectors are unique to my country???

Not available in South Africa, so I built my own for my fridge.

trip time is dependant on the amount of overload.
dead short should be instant while a 20% overload may take several minutes to trip.

Heavy magnetic devices do not need protection against short overvoltages (= what is usually called "surge protectors"; as electronic devices do), as the huge thermal inertia is what keep all of their material at safe temperature (the tiny mass of semiconductor components is what make them so sensitive - the amount of energy sufficient for destruction is small).

What they need is overload protection, protecting them from long lasting, but even quite small in value overloads, as they are usually quite dissipative and their steady state thermal budget is quite tight (while the low operation losses achievable with electronic allow great overdimensioning in power dissipation handling capability, so it sustain long term light overload way better)

That is the reason, why e.g. fridge motors use slow acting thermal relays: They have to protect from long term overheat (e.g. in case of failed start, when the motor current is ~5x the designed current; frequently happening with PTC based starters).
And as only long time overstress is dangerous, these protectors have on purpose quite large delay, to avoid unnecessary tripping on short time bursts (in the fridge e.g. during motor start).
Better protection systems use a thermal model of the protected device (e.g. bench saw motor), so are able quite accurately estimate the motor temperature and so the moment, when is really necessary to shut it down (and at the same time allow short time overlad).

And of course (when it is feasible), the best protection is the direct thermal sensor (switch) inside of the protected winding - it operate directly on the temperature, so no margin for inaccurate thermal flow or dissipation calculations are necessary and at the same time it avoid damage even when some heat management fail (e.g. blocked ventilation holes). These are popular mainly on transformers/coils (so lighting ballasts,...)

All these respond with delay from half minute (e.g. failed start in the fridge) till hours (e.g. 400W ballast in too hot ceiling)...

A surge protector protects from surges. It has MOVs (metal oxide varistors) or GDTs (a discharge lamp). In both cases the components absorbs the surge (and possibly dies), creates a short across L-N or L-E and trips a breaker

A better protector (which is not just surge protector) has also electronic circuit + relay that :
OVP / UVP - If the line voltage is too high or too low, the relay disconnects the output untill normal voltage is restored
Delay protection - If line voltage gets a rapid interruption, relay keeps output off ofr few seconds to few minutes

Most appliances that need surge protection, actually need all of them :

Electronic appliances for example get wasily damaged by any of those abnormal conditions, and not only by surges

Compressors (ACs etc) need OVP / UVP and delay, but unless there is some electronic control board too i doubt they mind surges too much



The Hyundai protector i saw (the cheap one) has 2 anorexic MOVs and 1 GDT connected in Y config. I would not trust it even as a surge rotector. The GPT SC9 COOL / ELEC is so much better, and has UVP / delay too

This is too complicated and makes the protection against voltage surges and lightning too much expensive as every time a surge or lightning strike, absobed by the surge, it would be killed, and this isn't practical to buy infinity surge protectors because of this.

Those protectors hold up several years each. Would you prefer to buy a new power supply for your computer / a new compressor for the AC every time some bastard electrician did not tighten well the neutral wire shared for you and a neighbor on another phase ?