Thursday, January 9, 2014

Computers, Power and Space Heaters

Just a safety note for folks who use a lot of electricity. In the winter, you might have computers and space heaters. Or you might (like me) live "off the grid". We use an inverter with a transfer relay to switch between battery power and grid power.

Recently, we had a bad smell. Here's the root cause analysis of the smell.

Do Not Overload AC Wiring. 

Figure out how many amps your computers, monitors and winter-time space heater actually use. The numbers are displayed in various places around plugs and plates on the backs of things. A few devices will list power in watts -- divide by 120 to get amps. A 1500W heater is 12.5A. 

Next figure out what your circuit breakers can handle. Many household circuits are 15A. A power strip may not even handle 10A. Two space heaters in one room is likely to exceed the wiring's current carrying capacity.

The root cause of the melted connector block might be a design flaw -- the block may have been too small for the rated load of 30A. While the device overall seems good, this kind of shabby engineering is alarming.