I don't see the problem, provided that you are within the current draw limits.
Surge protectors are usually made of components that cause a short when a surge happens, protecting the equipment downstream. It usually pairs with some kind of overcurrent protection (breaker, fuse, sometimes GFCI) to protect against the short the surge protector itself caused.
Having chained surge protectors it actually quite common. You may have a surge protector in your breaker panel, then in your powerstrip, then in the power supply of the device you have plugged in. Most good quality ATX power supplies have built-in surge protection for instance. They also all tend to have overcurrent protection too. The breaker panel has breakers (duh), the power strip may have a simple breaker too, and the device may have a fuse. In the UK, the plug itself may have a fuse, plus the breaker from the utility company.
The risk from chaining surge protectors is that it increases the risk of false triggers if one of them is defective. But it may also provide better protection. All in all, I wouldn't worry too much about it. Just don't overload that power bar and whatever it is plugged in.
I've never found a straight answer on whether it's ok to daisy chain surge protectors. Anyone know? I've been trying to avoid it based on a warning I don't understand, but it can be tough to find power bars without surge protection.
The reason it's a "bad idea" is that most surge protectors are power strips and you must be cautious when you daisy chain power strips. Likewise extension cords.
Why? Two reasons: You have to ensure the wire gauge on every link can handle the current, and at every junction (plug) the resistance is higher than in the wire itself. When electrical fires start they usually start at these plug junctions because they overheat.
The surge protectors themselves don't mind being daisy chained.
It's not very different from daisy chaining normal extension cords - safe if you know what you're doing (not exceeding the current rating on any of them). Most surge protectors are fused, making them safer to daisy-chain than normal extension cords.
I believe that it highly depends on the type of the surge protector, their ratings and the cable network involved. I do not think that it would cause issues in two surge protectors from power outlets connected in series, and depending on their rating and switching characteristics maybe both could trigger, I agree.
probably because it Depends, If you dont know its safer not to.
long answer (keep in mind i live in canada, im not a professional, this is just what i learned and trust, keep in mind above)
- As long as no wire/bar exceeds its max Amp your safe no matter how many things are plugged in or how long of a daisy chain, the max amp is usually listed.
- all devices should list the max amp they use, add up the amp's of all the devices connected to that wire and if its below your safe.
- if your breaker is 15 amp, virtually all normal extensions/power bars are rated for at least 15 amps which means doesnt matter what you do the breaker should* flip before any damage is done
- if breaker is above 15 amp most surge protectors have protection that will trigger if they exceed their max, most basic "splitters" and extension cords dont, eg if they dont have a switch or reset button they are pretty much guaranteed to not have this protection, be extra carful how much you load on those.
some good rules of thumb to keep in mind, look for imprints or labels that list amps, smaller wires can handle less, damaged wires can handle less then they did before and shouldn't be used, if a wire or connector warms when its in use its overloaded reduce the load on it, especially if it warms quickly.
here is a video that i liked that talks about it as well
https://www.youtube.com/watch?v=K_q-xnYRugQ
You need to know what the cable size is of the power strip and the current you are going to draw. If you have bar A with 14 ga cable plugged into the wall, and bar C With 18 gauge plugged into that, then with devices that don’t exceed C current rating (12 amps) and devices in A ( including the devices in C ) that don’t exceed A’s rating, you will be fine. The other way wall - C - A is the problem, C isn’t able to manage the full load.
Only buy known surge suppressor, there have been tear downs where the surge components were missing / fake.
Since surge comments are passive, chaining the surge components is not a problem.
I believe the question is if it's safe at all to do so rather than whether the protection works or not, though I'd have to be all ears about interactions between multiple parallel surge arrestors.
"surge protector" is what Americans call a passive device that splits one outlet into several, yeah?
The danger is overloading. Back in the days when the main things you plugged in were incandescent lights and space heaters, this was probably a big issue. With computer equipment and LED lights you have to have a lot more stuff - many outlets' worth - to reach the circuit's maximum capacity.
If the circuit and "surge protectors" are rated for 1800W (15 amps x 120V), officially you should limit yourself to 80% of that for continuous loads which is 1440W, so you can supply 14 laptops or small small desktops that use 100W each, or over 200 raspberry pis on USB chargers that use 5W each, and either way you're going to need a lot of outlets before you come anywhere close to that limit.
At least that's a rough estimate. Power factor could decrease that number by up to 50% and you can use the full rating for intermittent loads; I'm not certified to know the fine print. Point is that 10 computers can easily use less power than a single space heater.
It's sorta like plugging your PC into the wall plug next to it, and plugging your toaster into the wall plug in your kitchen...Yea, it would be easier to daisy-chain surge protectors from 1 outlet, but that's so messy. Like interior design layout, like circuit design layout?
And (I think) the copper circuits are so close that quantum leaps can occur -- electrons can just decide to jump from one piece of copper to another, straight through silicon or anything else, simply because the copper is so close. This means a VCC line can be giving charge to an unpowered neighboring circuit or memory cell without magnetically affecting it.
Not true. Breakers are most definitely intended to protect against overcurrent situations regardless of whether it's user or equipment caused. (For example, unintentionally plugging 30 amps of kitchen appliances into a single 20 amp circuit. Don't ask how I know.)
That being said, you should never intentionally rely on a safety feature to cut you out - they exist as a backup in case you screw up. The 14-50P to 5-15P adapter referred to by GP is an example of "I know what I'm doing". Just be sure to double check that you really do.
Edit: Also, consider that if you're in a jurisdiction where it's legal to have a 15 amp receptacle on a 20 amp circuit (many places in the US unfortunately) then a cable like this could allow you to draw a sustained current above what the receptacle is rated for but below what would trip the breaker. That's a fire hazard.
OK... but when you are dealing with a lot of laptops, enough to necessitate more plugs than a single 5-8 port power bar, it's probably going to run up against that limit.
I think the danger outside of load would be rare, but IIRC US specs for power cords specifically don't require compliance with daisy chaining (similar to C undefined behaviors?) and I bet most commodity power bars are cost-optimized to all hell.
Ah, I see. Sounds like the author was just confused then.
But I'm afraid I still don't see the advantage of having a fuse or (circuit breaker) in the plug itself. What is the rationale behind having two over-current devices in series? Circuit breakers and fuses (c.f. ground fault interrupters) don't really do anything to prevent a human from being zapped: They're there to prevent fires. You can easily stop a heart (or cause burns) without drawing anywhere near enough current to activate the protection. If Britons think circuit breakers are so unreliable that they need two, why put on on the plug instead of both in the distribution pane?
Surge protectors do have one magical electrical thingy in them: metal oxide varistors (MOVs). They're what shunt current in an overvoltage transient and they do age with usage.
Yeah, the risks mainly come with extension cords, like plugging a bunch of 10A appliances into a single 20A outlet via a 10A rated extension cord with multiple 10A outlets.
Appliances themselves with their own input fuses and captive cables are less risky, although some kind of internal wiring short could still get all melty.
It's true that sizing the plugs that way does prevent you from plugging a 20A appliance into a 10A extension cord, which makes sense.
Surge protectors are usually made of components that cause a short when a surge happens, protecting the equipment downstream. It usually pairs with some kind of overcurrent protection (breaker, fuse, sometimes GFCI) to protect against the short the surge protector itself caused.
Having chained surge protectors it actually quite common. You may have a surge protector in your breaker panel, then in your powerstrip, then in the power supply of the device you have plugged in. Most good quality ATX power supplies have built-in surge protection for instance. They also all tend to have overcurrent protection too. The breaker panel has breakers (duh), the power strip may have a simple breaker too, and the device may have a fuse. In the UK, the plug itself may have a fuse, plus the breaker from the utility company.
The risk from chaining surge protectors is that it increases the risk of false triggers if one of them is defective. But it may also provide better protection. All in all, I wouldn't worry too much about it. Just don't overload that power bar and whatever it is plugged in.
reply