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.
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.
This has been my experience. There was a corridor between 2 FL counties known for heavy lightning strikes. I serviced small sites that had their IT equip fried (exploded, melted) once or twice a year.
Putting it behind 4-6 decent, consumer-grade surge protectors turned out to be really effective. I was a bit surprised given how lightning can jump over protection during a strike.
To illustrate the area: An XO's home was hit. Char marks lined the walls wherever wiring ran. Pipes burst all over. Nothing plugged in or wired survived. The front door was blow into the street.
His grade school kids were home at the time; they were physically fine.
I really wish someone would come up with some surge suppressors that have a string of field-replaceable suppressors. Periodic maintenance, replace the suppressors.
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.
Although I do think I might have mixed some things up between regular power strips and those outdoors/industrial ones with a long (double/triple digit meter) rollable cable which my dad was a big user of back when he used to work in construction. Basically back when I was little he used to tell me never to plug power tools into a rolled-up “power wheel”, and I think that when I was later heard you shouldn’t daisy chain power strips I must have made that (wrong) connection.
You probably won't have issues charging iPhone from this thing or powering something for few seconds, so no need to go crazy about it, just something to keep in mind.
Either way, if your house has had a surge and other equipment has died that wasn't surge protected, probably a good time to replace all surge protectors in the house, they're not really meant to survive multiple large surges. They shunt the power destructively, just somewhere you don't care.
Is this a concern when buying used rackmount power conditioners (like used for live music setups?), to protect home IT gear? Can they be worn out without a sign that they are?
As a general rule, I wouldn’t run tools past 50 feet on anything smaller than 12 AWG (and really, 14 AWG is the smallest I’d go for any length; anything smaller isn’t safe for most loads).
It’s not safe, and it’s expressly forbidden by the NEC, see 11.1.5 below:
> 11.1.5 Extension Cords
> 11.1.5.1
> Extension cords shall be plugged directly into an approved receptacle, power tap, or multiplug adapter and shall, except for approved multiplug extension cords, serve only one portable appliance.
Daisy chaining extension cords is unsafe and not recommended. Only use extension cords that you’ve inspected and are properly rated for the environment (don’t use indoor cords outside, don’t use an outdoor extension cord outdoors unless it’s GFCI protected) and power usage of the device you are powering.
Any time electricity has to flow through a splice or mechanical connection, the possibility of a loose connection causing an arc and subsequent fire exists.
It’s unlikely to happen to you specifically, but it does happen and avoiding electrical fires is a good thing if it can be avoided.
Daisy chaining power strips is also forbidden by the NEC:
> 11.1.4.2
> The relocatable power taps shall be directly connected to a permanently installed receptacle.
For anecdotal experience, I've had both extension cords and wall plugs fail (nothing serious thankfully, but they did get a bit melted), but in those cases it had nothing to do with my extension cord chains, but rather an internal connection failure.
> 11.1.4.2
> The relocatable power taps shall be directly connected to a permanently installed receptacle.
A surge protector is a ‘relocatable power tap’ and must be plugged into a permanent receptacle.
So it's fine as long as you control the strip and keep track of loads (e.g. you know your spouse will never plug a vacuum into that handy receptacle you have there), but at work your EHS team will mark you down for it.
If you have said combination of electrical devices, and if you're assuming we're using an undersized UPS A + the combo of devices, why does the UPS B matter?
If you're going to overload the UPS A you're going to overload the UPS A regardless of UPS B, no? Daisy chaining or not, that doesn't seem like the actual problem to a knee-jerk thinking.
Daisy chaining a power bar with it's own circuit breaker can be ideal if it prevents someone from making the mistake of using a circuit in a way that trips a panel breaker, ie preventing your spouse from plugging a vacuum into a circuit shared by several rooms.
If I plug in a heater pulling 10A then sure, the 5A fuse will blow.
Daisy chaining multiways will increase the resistance in the earth wire which could mean you end up with a class 1 device with a fault connecting live to earth which would only punting say 8A to earth due to a high resistance (but then your circuit's RCD would trip with that), but is it a major problem?
With the US system, do you not have wires capable of 3A (say 24 AWG) which you can connect to a normal socket which also takes a 10A vacuum?
If that lamp has a fault where it pulls 6A, what protects the 3A wire -- i.e. there's a fault with your lamp which is plugged into a 15A circuit breaker, and the lamp draws 10A, it wouldn't trip the breaker, and that nice thin 3A lamp cord would melt.
UK only needed to introduce that because of their ring main architecture, which was fused at levels above a plug.
Also c.f. extension coils and pre-battery vacuums: both needed their cable full unspooled to reach their full load rating. Yet they typically lack technical enforcement mechanism to not rely on users being literate and willing enough to RTFM.
Something like 1.5 mm2 (only a 0.5mm diameter) is able to handle 12A if the insulation survives heating up to 60 degrees and 18A if 70 degrees is acceptable. The whole circuit would have a 16A fuse at the fusebox, so you're not going to get to 70 degrees.
Far from ideal, but also very very unlikely. Because a short would be over 16A and blow the fuse. So we're talking about some situation that's far from a normal load (any device that's close to such a load would need a different cable to be certified), while still remaining right under the maximum load of the fuse that's covering the circuit.
Homes aren't burning down all over the rest of Europe all the time, while fuses in plugs aren't a thing here.
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.
Those little switcher bricks are horribly inefficient: the 15W one I just pulled out of a drawer draws 0.8A on the primary. Realistically you're going to max out a 15A circuit around 20-30 of those, not 96 (1440/15).
Technically different, but often combined functions. The splitting bit is a "power strip", or sometimes a "power bar". The surge protection is switching off when there's a short or overvoltage in the supply, or other larger than expected power draw.
Not necessarily. There are “power strips” which turn one receptacle into several. Then there are sure protectors which are typically built into power strips. So not all power strips are surge protectors but almost all surge protectors are also power strips.
There are panel-mounted surge suppressors (which can protect all circuits coming from the panel), and also inline surge suppressors with a single output like this one: https://www.lojaclamper.com.br/dps-iclamper-pocket-2pinos-10...
surge protector = a device with electrical circuitry to help protect angaist surges and spikes.
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.
I believe some UPS brands might also void parts of your warranty if you use them with a surge protector plugged in.