Originally posted by: Eeezee
Okay, so I should buy surge protectors for my power squids then, if I want to protect my equipment from voltage spikes. I'm not really a risk, but the most of my stuff is surge protected anyway (with the exception of a few lamps). I don't have a lot of expensive stuff because I'm a poor college student, but investing in some surge protectors as I need them seems like a sound idea.
Here's another question, what if I were to plug a power squid into a power strip that is surge protected? Is this advisable if I'm mostly using low wattage appliances?
Re your "another question": no problem. You will see frequently warnings about not plugging too many items into a circuit, or making a nest of extensions, etc. They always say you'll overload the circtuit, but that will not happen. The circuit in the walls was installed with cables for the proper current capacity and a fuse or circuit breaker at the panel limits it to that current. If you plug in enough devices to exceed the capacity of the in-wall cabling, its breaker will trip out to protect that.
The real source of trouble is someone who uses a light-weight extension cord somewhere and then connects a heavy device (or several smaller ones). Here it's possible to overload the light extension cord without overloading the main circuit, so the breaker does not trip. The extension cord can overheat and cause real problems in this situation. The root of this trouble is too many things plugged into a LOW CAPACITY EXTENSION, and not the circuit load.
The less common type of trouble is using cords or plugs in poor condition. That includes cords that have (often hidden) frayed wires inside that reduce capacity, thereby increasing the danger of overheating, and these can result from cords that are exposed to mechanical abuse (like runing them under rugs where they get walked on). It also includes cords, sockets or multi-outlet taps with corroded contacts. Poor contact points produce high resistance at that spot, creating significant heat generation at one concentrated location under heavier loads.
So most of these problems are not in circuit loading, but in misuse of equipment added by the consumer.
By the way, just a small warming on surge protectors. The good ones can be quite sophisticated systems (and expensive). But the cheap ones may only work once. Many of these are based on simple MOV units connected between hot and neutral lines. They conduct virtually no current under normal curcumstances, but when voltage rises beyond a certain threshold they suddenly become great conductors and short out the high voltage for a brief time. This prevents the surge from going on down the line to your TV or whatever. However, during the brief time the MOV is doing its job it may well destroy itself with all of the enrgy being diverted through it. So when it's done, it is no longer there to repeat the process for the next spike. Your surge-protected power bar still appears to work just fine, but in fact there is no more surge protecting function. It is very difficult for the average homeowner to know this has happened.
