Circuit Breaker Ratings
Temperatures are starting to fall and it is time to pull out those little electric heaters again. Maybe to keep your favorite spot on the chair warm or keep your pets warm. Whatever the reason may be, you are faced with the same old problem. The circuit breaker always trips after a few minutes. In this section we have tried to break the numbers down so you can have a better understanding of why a circuit breaker trips.
First, lets take a look at some basic circuit breakers and what the numbers mean. Then we can move on to some simple formulas.
As you can see we have two different types of breakers here. They should look similar to the ones in your home or office. There are a couple of things that stand out here but the one thing we are interested in is the number located on the switched part of the circuit breaker. This number is the maximum amount of current allowed to pass through a breaker before it trips. Another thing that will be helpful to us is to understand that this number is listed in amps. The problem with this is that most electric heaters don't have their power consumption listed in amps. Most electric heaters will have this value listed in watts. Now that we know the breakers are listed in amperage and not wattage we can move on to the next step in figuring out our next factor for this simple formula.
All receptacles, that look identical to the one on the right, are wired for approximately 120 volts. If you are able to plug your electric heater into a receptacle that looks like this you know that the voltage is 120 volts. The breakers shown above are also 120 volt breakers. Now that we have this second piece of information we are ready to jump into our formula and see what exactly is happening when your circuit breaker trips.
Heater Ratings and Formulas
Most of the electric heaters we have encountered consume about 1500 watts. Some of the smaller heaters will consume 750 watts of power. Not sure how much current you heater is consuming? This number is always listed on the box that the heater was packaged in. About half of all heaters on the market will also have a plaque on the side or back of the unit that tells us this information. However, many smaller heaters don't have these plaques on them. It may be good the research the model number to find out how many watts it consumes. So how many amps is 1500 watts? Lets look at our first equation:
watts divided by the volts = amps
1500 watts /120 volts = 12.5 amps
This is a lot of current on a 15 amp rated circuit breaker. If you turn on a couple of lamps combined with a television, you are pretty much running at the maximum amount of current that is allowed to pass through your circuit breaker. If it is running on a 20 amp breaker you have a little bit of room before you trip the breaker. If you are trying to run two 1500 watt heaters on the same circuit breaker then you will always overload it, even if it is a 20 amp breaker. The easiest way to look at this situation is to try and remember that maximum amount of wattage allowed to run through a circuit breaker. This will bring us to our second equation:
amps multiplied by the volts = wattage
15 amps x 120 volts = 1800 watts
20 amps x 120 volts = 2400 watts
These are good approximate numbers to use when trying to figure out just how much wattage a 15 and a 20 amp circuit breaker can handle. One simple solution to these tripping problems is to plug your heaters in on different circuits. There are many people out there who will stretch out extension cords so they can put multiple heaters in one room. WE DON'T RECOMMEND DOING THIS. Most extension cords are cheap and are not manufactured well enough to be able to handle such a load. If you are willing to spend the extra money and buy a heavy duty extension cord, then there won't be much of a problem. We recommend at least a 12 gauge (wire size) extension cord. Another solution to this is to add additional circuit breakers and receptacles. Most electrical panels will have a at least one or two empty slots in them for additional circuits to be installed.