Answers to Electrical Questions About Grounding and Electric Baseboard Heater Locations
January 7, 2011
Steve Fancher asks:
I recently raised our house to dig out a new basement where the crawl space was, and in the process had to cut the copper water service and replaced it with plastic. Our 200A electrical is bonded to the copper cold water in the house, but how do I figure out how many grounding rods I’ll need to install to ground the system? Are there any other options?
According to the National Electrical Code®, you are required to install 1 ground ground. If it measures less than 25 ohms of resistance, then you are required to install 1 additional ground rod a minimum of 6 feet away from the first ground rod. You are not required to keep installing ground rods until you reach the 25 ohms of resistance.
I recommend installing 2 ground rods. I’ve worked all over the U.S. and haven’t seen anywhere where installing 1 ground rod will give you 25 ohms of resistance. In a residential application, the ground rods need to be a minimum of 8 feet long and 5/8 inch in diameter. I recommend galvanized over copper, but some areas require copper. You need to check with your local building codes department to determine your local requirements.
Another great source for grounding is a ufer ground or concrete encased grounding electrode. This is a minimum of 20 feet of rebar in your foundation or slab. This is a requirement here in Montana for all new construction foundations and slabs. Typically, the concrete contractor will do this and stub out a short section for you to attach to. I recommend having it stub out some place accessible near your electrical service.
I have a 12X18 home office with electric baseboard heat mounted beneath windows on the east wall. On the opposite wall is the thermostat, next to the entry door in one corner. I know this is the standard layout but I would like to move the baseboard heater to the (inside) wall where the thermostat is, and put a full length counter/desk/drawerbank/workstation on the east wall beneath the windows.
Not exactly kosher, but are there any major red flags?
The only problem that I can see is the heat rising and making your wall mounted t-stat turn off quicker. I recommend removing the wall mounted t-stat, placing a blank cover over this box and install a unit mounted t-stat on your heater.
Raymond Coonrad asks:
Can furniture be placed in front of electric baseboard heaters?
Yes, per manufacturers instructions. I recommend keeping the furniture at least 12 inches away from the heater. Please keep in mind that the furniture will block the heat.
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