Power surge damage

[QCGuy]

Hello,
I would like to know if a power surge can do damage to some equipment and not other in the same building

 

[westom]

I would like to know if a power surge can do damage to some equipment and not other in the same building

Absolutely. That characteristic is normal. To understand, first, learn what a surge is.

First, it is electricity. Therefore it is a current that exists simultaneously everywhere in a path from the source to earth ground. Yes, current must have one path going into an appliance and another path outgoing - or a surge current does not exist.

Second, nothing stops a surge. Nothing. Voltage increases as necessary so that constant current remains constant.

Third, which appliance will make that connection to earth? Every appliance contains significant protection. But some will make a better connection to earth than others. A surge may find one or some paths to earth. Normal (for example) is an adjacent VCR destroyed while the TV remains unharmed. VCR made the better connection to earth; acted as a surge protector for that TV.

Effective protection means energy does not enter the building. Routine is to have a direct lightning strike to utility wires into the building - and no damage. Even the protector is unharmed. But only if a protector is actually designed and earthed to provide surge protection.

Which appliance(s) makes the better connection to earth? Which appliance has less internal surge protection? What is the incoming path of that surge? How large is that surge? All questions that answer what may or may not be damaged.

Why is an appliance damaged? Because a surge was permitted inside the building - human error. And because a surge then went hunting for earth ground destructively via appliances. Protection is always about where energy dissipates. A protector is only as effective as its earth ground – so that protection already inside every appliance is not overwhelmed.