A fire broke out at the Broncos stadium this past week, and just yesterday a wildfire sparked up and threatened to destroy part of Boulder. And as an unfortunate coincidence, I wanted to talk about fire safety today. So, instead of ruminating about how fires are now a year–round hazard in Colorado (on top of the seasonal hazards of floods, hail, lightning, and tornadoes), let’s talk about how to set up a home studio without burning your place down.

Many of us who have home studios don’t really have any sort of purpose–built room for our music. Instead, we just have to take our living situation and make it work — think of basements, bedrooms, garages, sheds, and the like. So, the power situation can be a little bit lacking.

People often turn to extension cords and power strips, but these have made many electricians and fire marshals uneasy. It’s pretty understandable; extension cords and power strips bypass the few safety features that the US electric code has. In far–flung dystopias like the UK, the electric code puts things like fuses built into all plugs. It’s as if they don’t want you to go to the hospital or something.

Here in the States, the only thing you can really count on is your circuit breaker. The circuit breaker in your home does something very specific: it keeps the wires in your walls from catching on fire. For instance, if you try to draw more than ten amps through a ten–amp circuit, the breaker will open. This will keep the wires in the circuit from heating up, melting their insulation, and bursting into flames because they tried to carry more current than they were designed to.

Now, consider another situation: you have something that draws five amps and you’ve plugged it into an extension cord that can only handle 2 amps. This is a dangerous situation, as the extension cord can easily overheat and cause a fire. But don’t expect the circuit breaker to trip, since the wires in the walls are fine.

Now here’s the thing — there is in fact a way to use extension cords safely, you just need to do a little math.

Think back to high school physics, where you were probably taught the following formula: voltage (measured in volts) multiplied by current (measured in amps) equals power (measured in watts).

So, if you need to connect a 30–watt guitar amplifier to an extension cord, set up the formula based on your situation, and solve for current:

It may seem shocking (bum–dum–tiss), but the big Vox amp in that photo maxes out at 30 watts, drawing .25 amps of current.

On its own, 1 amp is actually a lot of juice, but many devices will quickly stack up. So you have to add up the total maximum wattage of all the devices connected to the extension cord and divide that sum by the voltage coming out of your wall. In North America, the continent runs on 120 volts, but some say to use 110 volts for your math just to be on the safe side (this is because an increase in the number of devices can result in a voltage drop, not to mention how each device has its own resistance).

Doing the above mathematics will give you the total amperage. Now you just need to double–check that result with the rating of your extension cord/power strip. I recommend giving yourself some headroom — if you’re drawing 5 amps total, use a cord rated for 10 or 15 amps.

The main reason safety experts say “don’t use extension cords” is because it’s easier to just say “no” than it is to expect the general public to do this kind of math/research. To add to the confusion, extension cords use American wire gauge, meaning that a smaller number indicates a thicker wire (and higher amp rating). And even if you’ve done the math, you still need to take some extra precautions.

For one, try to keep your extension cords short. The resistance of a piece of wire will go up as its length increases, which will result in a drop in voltage at the end of the wire. So to produce the same power, when the voltage goes down, the current must go up.

This is one of the reasons safety experts will also advise against daisy–chaining extension cords. You can easily create hazardously long runs of wire, and loose connections between the cords can also lower the voltage (not to mention cause fires/electric shocks on their own).

While we’re at it, daisy–chaining power strips is a terrible idea, as the first strip in the chain could have way too many devices connected to it.

Also, get a grounded extension cord if you need one. Never, ever use a cheater plug on a three–prong device.

When it comes to long–term extension cord use, no one will tell you that there’s a safe way to do it. I think there ostensibly is, if you use a heavy–duty extension cord, keep it clear of foot traffic, keep it exposed & uncoiled so heat can dissipate, and try to avoid touching it as much as possible to reduce metal fatigue.

Extension cables can wear out, so consider replacing them regularly. I ended up working with an electrician to install some extra outlets in the basement, which I highly recommend doing if you’re relying on extension cords too much. And for extra safety, I recommend that every home studio have a fire extinguisher. For electrical fires, you need a CO2 or dry powder extinguisher, rated for class “C” fires.