Mrs. Trees and i both think we’ve heard/read that it isn’t safe to plug a space heater into a surge protector.
Neither of us can say for sure why we think this, or why it is unsafe.
Can anyone see a downside, provided that i know to check the amp rating on the surge protector? Shouldn’t this be safer than plugging it into the wall outlet?
No. The question is why would you want to?
IANAElectrician, but the safest choice is plugging it straight into the wall. The space heater probably draws 1500 watts, which could be close to the limit of the circuit, if it’s a 15A breaker.
Do you think the surge protector will protect the heater or the house circuit? I don’t think so. Adding another device in the chain just adds a potential point of failure. And one risk with using a surge protector is that something else could also be plugged into it that could exceed the circuit’s (or the surge protector’s) capacity and pop a breaker. If everything works properly, that shouldn’t be a big deal, but surge protectors are notoriously variable in quality.
AFAICT, there’s just no benefit to doing this. If you need to extend the distance from the wall, use a properly rated (15A) extension cord.
A surge protector is also just a short extension cord and we have been repeatedly told at work not to plug a heater into any extension cord, but to plug it directly into an outlet.
A properly rated extension cord shouldn’t be an issue, but a lot of workplaces don’t like extension cords for high-powered devices like space heaters because users who aren’t well-versed in electrical requirements sometimes don’t check cord ratings - and they also don’t like extension cords because they tend to become trip hazards.
@Happytree, if your surge protector is adequately rated for the sum total of everything that will be plugged into it, and the space heater doesn’t exceed the rating for any individual outlet on the surge protector, then you should be fine.
This video from one of my favorite YouTubers explains a lot of what you need to know.
Those cheap power strips are O.K. for low to mid power loads. But you shouldn’t plug anything in to them that pulls a lot of current, e.g. heater, blow dryer, microwave oven.
Assume you have other devices plugged into a multi-outlet surge protector that do need protection from a voltage surge. The heater is drawing a lot of current. I don’t know how surge protectors work, but given that they are rated are in Joules, doesn’t that imply that the level of protection for the other devices is significantly compromised?
I’m uncertain from the answers so far as to whether it does or does not make a difference if the space heater is the only thing plugged into the power strip. I have very few options for mine reaching my work space; it’s either power strip or have the heater less than a foot away from my chair and much less light.
I was kinda tip-toeing around my intentions to avoid a lecture, but here goes:
If i have the space heater on and the coffee pot on at the same time, a breaker trips in the basement.
I was hoping if i had the space heater plugged into the surge protector, the breaker on the surge protector would trip first.
To be clear, i don’t want to plug anything else into the surge protector but the heater. The coffee pot is in another room.
I’m not paying for an electrician; i rent. I bet my landlord would tell me to just stop using the heater.
I know i could sue the landlord, blah, blah, blah, but I just want to know about the surge protector thing
Thanks for all the replies so far, I’m leaning towards just remembering to shut the dang heater off before i start my coffee.
No.
Those cheap surge protectors don’t care what’s plug into the power strip. They simply contain some MOVs between hot and neutral, and possibly between hot and ground. The MOVs will “clamp” the voltage when the voltage briefly exceeds a threshold value.
And for good reason.
The solution is obvious, and it’s not a surge protector.
Someone please correct me if I’m wrong:
My impression is that the purpose of a surge protector is to protect the items that are plugged into it (computers, etc., which contain delicate electronics) from electrical surges. And this is entirely different from the purpose of the breakers in your basement, which is to prevent the wires from overheating and causing a fire.
It wouldn’t.
If the coffee maker is plugged into the wall and the space heater is plugged into the surge protector, the (probably) 15A space heater won’t have a reason to trip the 15A (probably) breaker on the surge protector.
But when you turn the second of those two appliances on, you’ll trip the house breaker, probably not cause a surge, and the space heater will be left wondering what happened.
You’d be overloading the house circuit, but not the surge protector.
ETA: it’s entirely possible that the space heater is the only thing you can run on that circuit at any given time, and that nearly anything else (beyond known really low amperage draws) could similarly trip the house breaker.
Some surge protectors also have a built in circuit breaker, and I’m guessing that’s what the OP is referring to?
Not sure. At any rate, it doesn’t matter. The branch circuit in the home is simply being overloaded. The solution is to use separate branch circuits for the heater and coffee pot.
So can you explain why they are rated in Joules? I don’t understand that.
It’s somewhat involved. This paper explains it. Basically, it’s the amount of energy the MOV can safely “absorb” when it is subjected to a defined transient. (The MOV takes the “dangerous” energy that was in the transient and turns it into heat.)
Thanks folks. Makes sense to me.
The joule rating of a surge protector has to do with how big a spike of energy on the supply side it can protect your devices from.
The power consumption of the devices that are plugged into the surge protector don’t matter.
There are several ratings with surge protectors. The joule rating is just one of these.
Your typical power strip type surge protector uses MOVs (metal oxide varistors). The way these work is that under normal use, they are basically switched off and do nothing. However, if the incoming voltage gets high enough, the MOVs switch on and basically create a dead short. The incoming voltage spike is then clamped by this short circuit, which prevents the voltage spike from damaging your equipment.
A cheap power strip will have just one MOV between hot and ground. Better power strips have multiple MOVs between hot, neutral, and ground so that spikes on any line can be clamped by the MOVs.
The joule rating is how much energy these MOVs can absorb. All of the energy from the incoming voltage spike gets turned into heat in the MOV, and if the spike is big enough it can blow out the MOVs and some of the spike can get through. A typical power strip will usually be a couple hundred joules. A better one might be rated at 1,000 joules or more. A really good whole house surge protector (the type that requires an electrician to install) might be around 4,000 joules, though some of the cheaper ones at Home Depot and the like aren’t any better than power strips.
To put things in perspective, your typical lightning bolt contains about a billion joules. While there are ways of protecting buildings from lightning strikes, you can’t buy an off the shelf surge protector that can protect your home from a direct lightning strike. However, lightning can hit power lines and travel for miles, and often by the time that power spike hits your home it could be spread out enough that a surge protector can stop it, so surge protectors are definitely useful. They just can’t handle a direct strike. Not even close.
The next rating that you need to be concerned with is the clamping voltage. This is the voltage where the MOVs turn on and do their thing. The lower the number the better. Typical values for surge protectors are somewhere around 400 to 600 volts.
There are two different amp ratings with surge protectors. One is how much current the surge protector can shunt to ground, which will be a fairly large number, like 50,000 amps (or 50 kA) to 80,000 amps (80 kA). You typically only see this number on whole house surge protectors, and the higher the number the better.
And again, to put things in perspective, your typical lightning bolt is going to be about half a million volts and about 30,000 to 50,000 or so amps.
The other amp rating is how much current the surge protector can supply, typically somewhere around 12 to 15 amps. The higher the number the better. A typical U.S. electrical outlet is rated for 15 amps.
A 15 amp power strip should be able to handle a space heater. However, in my experience, while it will probably work for a while, eventually the heat dissipated in the power strip will lead to a fault and the power strip will fail catastrophically (fire, smoke, etc). Don’t plug space heaters into power strips, whether they contain a surge protector or not.
One final note about surge protectors. An incoming power spike will often blow out the MOVs, which is great since that’s it’s the MOVs job to absorb the incoming spike and protect your equipment. However, especially on cheaper power strips / surge protectors, there is often no indication at all that this has happened, so you have no way of knowing if your MOVs are blown or not. Better surge protectors will have an indicator that tells you if your MOVs are still good.
No, Electrically they are both equally safe unless of course, you put the surge protector near the heating heating element and melt it.