Poor man's transfer switch
I needed a transfer switch on my house to hook up my generator. My
generator is manual start, and an automatic transfer switch - at over $1000 -
seemed excessive. I couldn't just hook up with a cord either - my
generator is 150+ amps!
I have 150 amp service on my house (my main breaker - in breaker box - is 150)
so I looked for a simple way to connect.
What I ended up with was two 150amp line breakers, a NEMA 4 enclosure, and a
home made EXCLUSION BAR.
I hooked this up at my meter box.
Yes, I had to pull the meter to do this (it just plugs in), but I simply called
the power company and asked them to re-tag the meter.
Here is a before-and-after view of the connection:
THE EXCLUSION BAR IS THE MOST IMPORTANT CONCEPT HERE!
The exclusion bar keeps you from running both the mains and the generator at
the same time. This is VERY important to safeguard utility workers. (not
to mention the huge drain on the generator!)
In this example, I simply mounted an aluminum bar on a bolt through the
cover. Simple and effective.
Do NOT, never EVER, put together a permanently wired circuit for a standby
generator WITHOUT some type of exclusion bar or interlock that prevents the
connection of main power and generator power simultaneously.
Some people put their generator on a breaker in their main breaker box.
Yes, that works. Yes, it is VERY UNSAFE.
You MUST BUILD AN EXCLUSION DEVICE!
Here is an example on a breaker box:
The exclusion bar slides up and down on the two mount pins, making it impossible
(or very difficult anyway) to turn on both the generator's breaker and the main
breaker at the same time. If you don't have a main breaker (it's probably
in your meter box) then you CANNOT do this! Make your generator connection
where you have a MAIN breaker. Or get a transfer switch / distribution
panel.
Let me say again: if you wish to wire a generator into your home's
distribution panel (breaker box) then you MUST make provisions to prevent the
connection when incoming lines from the power company are also connected.
In a total disaster situation (say Katrina?) you could pull your meter.
Otherwise, always use a transfer switch or some other type of exclusion device.
All of the above assumes you are using correctly rated wiring, boxes,
breakers, ect... If you are uncertain, contact an electrician.
