What hobby could be safer than gardening? Especially if that garden is indoors? You may be hard pressed to think of a hobby with less risk of personal injury. However there is a risk that might not seem too plausible. That risk is fire. It doesn't happen often but it can happen.

We have seen only one fully involved fire, where the fire department was required and the dwelling was pretty much destroyed. However we have seen literally dozens of "close-calls" where fire didn't actually start but there was lots of electrical arcing, smoke and noxious fumes. We have heard a few reports of a fire breaking out but was discovered quickly and extinguished before any major damage was done. Scary stuff indeed.

The cause of all these incidents was basically the same. Poor electrical connections where high draw electrical devices plug in (mainly grow lights and "window-shaker" air conditioning units).

What seems to happen in most cases is that the plug isn't plugged all the way into the receptacle. This lets moist air get to and start to corrode the contacts of the plug. Eventually the corrosion can lead to an arc when the device turns on and there is a sudden draw of electricity. This arc causes even more corrosion as well as lots of heat. In some instances the arcing can cause enough heat to start melting the plastic plug and/or socket. Once the plastic starts to melt there starts a kind of chain reaction where the melting plastic creates more arcing, building intense heat which melts more plastic.....etc. if you are lucky the circuit breaker will trip and there will be no further problem. Once in a while the arcing will not draw enough current to trip the breaker and things can get intense sometimes causing a fire.

In grow rooms the air is frequently very humid and can speed the corrosion of the plugs/receptacles. I have seen cases where light ballasts are positioned in a garden where nutrient solution actually splashes onto the ballasts and their plugs. This is doubly problematic as nutrient solutions are salty which speeds up the corrosion process. The pictures below are from our "Hall of Flame". They show what can happen when plugs are left partially out of the sockets. Click on the pictures to enlarge them.

The photo on the left shows the charred remains of the connection of a output socket and plug of a 400 watt high pressure sodium ballast. The owner was home and smelled the smoke. The unit was unplugged in time. Some of the lighting companies like Sunlight Supply have addressed this issue and now have sockets and plugs with tabs that positively lock the two together thus sealing and protecting the connections.

The photo on the right shows timers that have started to arc. One had a 1000 watt HPS grow light plugged in. The second times had a room air conditioner plugged in.

Fact is that virtually any electrical connection can corrode and arc. This is particularly true with equipment that draws heavy current loads. It is also fact that plugs have a way of working their way partially out of their sockets. Vigilance must be maintained and you should frequently inspect your connections, making sure that they are snug and corrosion free. Things to look for are very dirty or discolored connections. I have also noticed that frequently the plastic of the plug begins to swell and get slightly melted looking around the metal contacts.  If you see anything that doesn't look right - get it fixed - now!! Be Safe!!!