A couple weeks ago, Erie, Pennsylvania experienced a major wind storm with lots of rain. Living just a mile from the shores of Lake Erie means that we typically get the worst of the winds. The street we live on has overhead power distribution, telephone, and Internet lines, so they are more vulnerable than underground buried lines.
During the aforementioned storm, a very tall pine tree in the yard right on the corner where the main feeder branches to our road snapped about halfway up and pulled the lines right out of their connections on the mains as it fell. To make a long (45 hours to be exact) story short, our entire street was without power for nearly two days. That is an unacceptable situation when you run your business from home, as I do for publishing both my RFCafe.com and AirplanesAndRockets.com websites.
Up until about a year ago, we had a 5,500 W, 230 V generator that we bought back around 2002 when a similar outage occurred. The power hadn't been out for more than an hour or so since then, so we confidently gifted it to our daughter in Greensboro, North Carolina. They tend to have a major ice storm every couple years there that wipes out power for a day or two at a time. She owns and runs Equine Kingdom Riding Academy (a gratuitous plug for her business).
Anyhow, after about 8 hours of no power, we went to Sam's Club and bought a 3,450 W, 120 V generator. Our house has gas heat and hot water, so other than a 220 V air conditioner unit and the electric dryer, everything we actually need runs on 120 V. A few heavy-duty extension cords fed the refrigerator (18 cu.ft.), freezer (5 cu.ft.), two computers and monitors, and a couple floor lamps. Turning on the gas stovetop burners actually kept the house comfortably warm. I vowed at the time to finally, after many threats to do it, install a transfer switch to make the whole process as simple as possible. So, I ordered a Reliance Controls 3006HDK Transfer Switch Kit from Home Depot.
The Reliance 3006HDK Transfer Switch Kit comes with the fully pre-wired panel that has six circuit spaces, each one with its own separate circuit breaker and break-before-make transfer switch. There are four single pole 15 A breakers and two 20 A single pole breakers with a tie bar in-between for a 230 V circuit. I removed the tie bar to use them as single pole circuits. The bus is broken into two phases to accommodate the standard household service configuration. Since I am only using single phase, 120 V circuits everywhere, the two sides of the bus were wire-nutted together.
Because I had plenty of 10/2 Romex wire on hand, two separate cables were run from the indoor transfer switch box to the outdoor weatherproof plug enclosure. Even though there is only a need for a single 120 V, 30 A circuit now, it will be good to have provisions for a 230 V, 30 A generator if needed. As long as the second wire was there, I went ahead and connected both sets of conductors in parallel; that'll result in half the voltage drop across the Romex wire from the generator to the transfer switch.
A section of 3/4" flexible conduit and 90° connectors are included in the kit for connecting to the main circuit breaker panel. Along with a ground and neutral wire for tapping into the ground bus bar are six pairs of red and black stranded wire (labeled 'A' through 'F'). For each circuit you want to have fed by the generator, remove the branch feeder wire from the original circuit breaker and wire nut it to the black wire, and then connect the corresponding red wire to the breaker. 'A' and 'B' are the 20 A circuits and therefore have 12 AWG wire and circuits 'C' through 'F' are 15 A circuits with 14 AWG wire.
I chose to put the following six circuits on the transfer switch box:
'A' - 20 A, kitchen with refrigerator
'B' - 20 A, basement with freezer
'C' - 15 A, furnace controls & blower
'D' - 15 A, computer & modem receptacles
'E' - 15 A, bedroom receptacles & lights
'F' - 15 A, living room & basement lights
With the exception of the furnace circuit, there are lights and receptacles serviced other than those specifically named. In the 1950s, when this house was built, the National Electric Code did not require receptacle and lighting circuits to be separate, and for that matter there were originally no GFIC or AFIC circuits either.
The outdoor connector box is supplied with a 4-prong plug for a 230 V, 30 A cable socket, and the 10-foot long cord that comes with the kit has a mating plug on the generator end and socket on the connector box end. My generator needs a 3-prong, 120 V, 30 A plug, so I needed to cut the original plug off the cable and replace it with the appropriate plug.
Once all the wiring was completed, I connected the generator, fired it up, and tested the transfer switch operation. It's good to go. I'm not looking forward to another power outage, but at least now I'm ready for it! BTW, this generator averaged about 4 gallons per day while running continuously. At $2.50/gallon that works out to about $10/day, or $300/month - much more than my typical $90/month electric bill.
Posted January 16, 2016