My small office has a 20A breaker and we have to run a space heater in the winter or else we freeze to death. Whenever someone turns on the coffee maker, the office circuit breaker trips and everyone's computers are down for 10 minutes while someone goes and resets the breaker. We've tried implementing a policy of shutting off the space heater before starting the coffee maker, but it's too easy for people to forget.
I plugged both devices into a power strip rated at 15 amps, and I assumed since it had a reset switch, it would actually trip at 15A. Much to my surprise, the office breaker still tripped. I also tried a different 15A power strip with the same results.
I then plugged the power strip into a Kill-A-Watt meter and it measured over 22A with the coffee maker and space heater both running, before I unplugged everything. My best guess is that both the office breaker and the power strip have time-delay breakers, but the office breaker is on a shorter delay. Another theory is that the power strips are manufactured to very loose tolerances and will only trip if the current far exceeds 15A.
So my questions are:
- Why isn't the 15A power strip tripping? Should it even have a time delay?
- If we just need to buy a better power strip, is there an easy (and safe) way to test at what current a power strip will trip, aside from plugging a bunch of stuff in and potentially tripping the office breaker instead? (Edit: I think I found the answer to this one.)
- If all else fails, what can I install between the wall and the appliances which will trip the space heater and coffee maker before the office breaker trips?
Best Answer
Put your computers on a UPS, even a small one. Just protecting yourself from short power outages will save you a bunch of downtime. Even if you resolve your overload issue, this is still worth it.
Most computer users today can get by with a laptop that's under $500, giving you built-in battery backup & portability in a compact, low-power package. Plug it in to your keyboard, mouse, and monitor the same as your desktop today, so your work experience doesn't change.
The power strip you linked to (http://www.cyberpowersystems.com/products/surge-protectors/home-surge/6050S.html?selectedTabId=specifications&imageI=#tab-box) doesn't appear to have a breaker. I think that whoever wrote that was just confused about what it means to be rated for 15A.
If your coffee maker and space heater are in the same location, you could plug them into mutually exclusive switched outlets. You'll need:
A steel square box, and an appropriate face plate
A regular duplex receptacle. 15A or 20A can work
a 3-way switch
cable
plug (15A or 20A, to match the recep)
fittings
Snap off the tab on the hot side of the recep, then run short leads from those 2 screws to the 3-way switch. This will let the switch choose one socket or the other. Plug in the heater on one and the coffee maker on the other. Now it's easy to make sure only one is in use at a time.
(Later I will add some pictures and other details. If anyone has pointers to the correct fittings and cable, please comment.)