If so, what type of protection is recommended? And is it still needed if you have a whole-home surge protector installed at the load center? (I do, FWIW).


Wow some bad info here. Surge protection as identified for line surges from the power company or on separate circuits are best protected as close to the main as possible. If you have a dedicated circuit for the fridge you need no other protection. The whole home protection will take care of small motor loads better than a point of use in the case of a dedicated fridge, washing machine (laundry circuit is dedicated) those are most homes big loads other than a well and again normally a dedicated circuit or sub.

If you have sensitive electronics don’t put them on the same circuit as motor loads. Most point of use issues I have been called in for are meltdowns on homes that did not have whole house suppression. The elcrapo point of use “ surge protectors” really do almost no good and when they actually dump a good jolt to ground many melt down.
Why do I say this the point of use normally have a much higher breakdown voltage so you think they are doing a good job because the little green light is on but they don’t start working in many cases until over 800v spikes, if they don’t have a monitor that verifies they are functioning they are useless as you don’t know if they are good (they are designed to blow open when overloaded). If you could not get one with a monitor because you don’t have a proper ground is it still good? If your whole house unit is still green your point of use will be also. So as you can tell I am not a fan of point of use I have seen probably close to 50 melt down melt carpeting and damage furniture but none caught fire yet smoke yes. They all had the same issue they were not mounted on a non combustible surface. Well do you want a point of use where it can do damage inside or a unit mounted on or close to your breaker panel that dose a better job in the first place.

  • Sorry but you're dead wrong on the distance issue. Most manufacturers of MOV type surge protection, which is 99% of what's on the market, have whitepapers explaining that the protection works best when it's closest to the protected equipment due to the effect of inductance in the wire on let-through voltage. This is the same reason you keep the leads as short as possible when installing surge protection at the panel. Remember, they are parallel devices, not inline / series surge protection. – batsplatsterson Dec 3 '20 at 11:02
  • surge protection as close to the main as possible is the best if you read my answer second sentence I did say exactly that! not only am I a electrician but I have a degree in electronics. It makes absolute no difference on dedicated circuits and the cheap point of use strips because the MOV’s have a higher break down voltage. The cheap point of use ones are also known for melting down I have read about them catching fire but I have only observed meltdowns. – Ed Beal Dec 3 '20 at 14:15
  • With all due respect (and you are due considerable respect!) that is what I am disputing, nearer the main breaker is less effective than protection near the protected equipment. – batsplatsterson Dec 3 '20 at 15:44
  • Absolutely no difference on a dedicated circuit with the main being protected as I said, if you want to suggest a product other than the standard melt down type of devices that have higher breakdown voltages it could be true on a non dedicated circuit but the meltdown models having a higher breakdown voltage could be attached directly to the motor and do less good than most whole house units. It’s all in the breakdown voltage and the joules they can dump. Both are substandard in almost all point of use plug in units. I don’t know of anyone that thinks these block a surge they dump to ground. – Ed Beal Dec 3 '20 at 16:03

Many modern refrigerators have built-in protection . The last one I had burn out due to power surges was a 1980 model GE ( burned out start capacitor - replaced). My present 2010 Samsung has been through many power outages including instantaneous on and off as the power company works on the line. I try to turn it off but often it is too late. So , I do not think it would be a benefit for a modern unit.

  • The small MOVs in appliances are helpful but they don't last long, and you have no way of knowing how much they have degraded. You might want to install some point of use protection before they are done. – batsplatsterson Dec 3 '20 at 11:14

There are some common misconceptions, even with experienced electricians, with respect to surge protective equipment.

Most common surge suppressors are shunt type and function as parallel devices. When you use a power strip, it doesn't block surge current from reaching the receptacles, it bleeds off surge energy before it gets to those receptacles.

The electronic component that achieves this function in most commonly available surge protection is a metal oxide varistor, or MOV. MOV's come in different sizes and different qualities with respect to how they react to voltage changes. Some MOVs are more sensitive than others.

Shunt type surge protectors like MOVs work better when they are closer (in wire distance) to the protected equipment due to the effect of the inductance in the wires. Longer leads to the MOVs and longer wires to the protected equipment have more inductance and allow more surge energy through to the protected equipment.

The whole house protector on your panel is good, but it's better still to have point of use surge protection as well. The point of use protection will usually react faster (more sensitive) and will allow less voltage through to the protected equipment. The panel protector protects everything in the house and helps dissipate some of the energy so the point of use don't have to do it all on their own.

The major components of appliances are generally pretty robust so traditionally people use more basic point of use surge protection for them. The receptacles with built-in surge protection were consider pretty basic but adequate.

However everything has a microcontroller any more, and nothing's repairable any more - appliances are made to be disposable - and they are certainly more expensive than ever. So it makes more sense to use better point of use surge protection for appliances today.

MOVs are sacrificial. Sometimes they get hit with a big surge and explode. Sometimes over time they erode blocking smaller surges over time. Usually the MOVs in appliances are on the small side and don't have a real long lifespan. I have never seen an appliance that lets you monitor how much life is left in the MOVs. So although it's good that there's surge protection in appliances, it still makes sense to use point of use surge protection.

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