Transfer switch selection.

[Chariotdriver]

 
  On the bus that we just bought the person that "wired it up" has brought power in from the Generator AND the Shore power into the breaker panel via 2-70 amp breakers instead of running it through a transfwe switch!!
I could see several things severely wrong with this as in sending power down the shore power from the generator and electrifying the bus!
So, what are the recommendations on getting this straightened out.
In the shore power area there is the power cord from the generator in the same are and I think I could place the transfer switch there in that space.
Any ideas?
 

[Sean]

This arrangement is common on standby generator panels and perfectly acceptable IF the two breakers in question are equipped with a sliding-bar lockout system, which ensures that only one of the two breakers can be in the "on" position at any given time.

Without this system, it is quite dangerous, as you said, as well as illegal.  Install either a manual or automatic transfer switch ahead of the panel.

-Sean
http://ourodyssey.blogspot.com

[Chariotdriver]

 Thanks,
Any suggestions on what brand, or are they all the same basically as far as durability?
Thanks again,
Phil

[JackConrad]

   Look on EBay for Iota transfer switch. You will need to know if your generator is wired for 120 or 240 output and whether your shoreline cord is 30 or 50 amp. If your generator is 240, OR your shoreline is 50 amp, you will have to use the 50 amp switch.
   Another simple solution is to terminate you shoreline cord and your generator cord each with a separate receptacle. Then, intall a plug on the cord that goes to your main panel. Simply plug the cord from the panel into the receptacle from the power supply you want to use.
   An even simpler system it to connect your shoreline cord directly to your main panel and install a receptacle on your generator output cord. When in a campground, plug your shoreline into the campground connection, when not in a campground, plug the shoreline cord into the generator output receptacle

[Chariotdriver]

 Thanks you all!
I believe that out of all the forums (even the ones that I've been kicked out of) you guys and gals are the nicest and most willing to spend your time replying to these request for info.
It's a great feeling to log in and see numerous replies with great info.
Thanks again,..
Phil

[buddydawg]

An even simpler system it to connect your shoreline cord directly to your main panel and install a receptacle on your generator output cord. When in a campground, plug your shoreline into the campground connection, when not in a campground, plug the shoreline cord into the generator output receptacle

I am wiring my bus as we speak and this is the configuration I am going to use.

[Lin]

Using either of the two manual systems suggested is easy and foolproof.  I personally need both.  They also make it easy to install a transfer switch for your inverter.

[Sean]

Careful...

If you use a 50-amp transfer switch, as some have recommended, you will need to make certain that the generator has a 50-amp breaker upstream of that switch.  I presume from the fact that your main breakers are 70 amps that the generator can put out close to that.  For a 240-volt system, that's a 16.5kW generator (which would generally be 15kW continuous, 17kW standby).

If you use a 50-amp transfer switch, you'd basically be de-rating your generator to 12kW.  Personally, I would not give up that much of my power supply.

That said, 70-amp transfer switches are very expensive.  I ended up building my own (details on my web site, http://www.ourodyssey.us).

FWIW.

-Sean
http://ourodyssey.blogspot.com

[Chariotdriver]

 Thanks for all the info provided,..
The breakers are not locked out from each other, when I asked why to the previous owner, he said that he was the only one that messed with the breaker box.
It is a 17kw generator and will look at the breaker at the actual generator to see what size it is.
Thanks
Phil

[Chariotdriver]

   Look on EBay for Iota transfer switch. You will need to know if your generator is wired for 120 or 240 output and whether your shoreline cord is 30 or 50 amp. If your generator is 240, OR your shoreline is 50 amp, you will have to use the 50 amp switch.
   Another simple solution is to terminate you shoreline cord and your generator cord each with a separate receptacle. Then, intall a plug on the cord that goes to your main panel. Simply plug the cord from the panel into the receptacle from the power supply you want to use.
   An even simpler system it to connect your shoreline cord directly to your main panel and install a receptacle on your generator output cord. When in a campground, plug your shoreline into the campground connection, when not in a campground, plug the shoreline cord into the generator output receptacle

I did find an Iota 100 amp auto transfer for around 250.00 plus 25 shipping.
  I do believe that it is wired for 220 as the power is coming into the panel via a 220 breaker( back feeding both sides of the breaker box with 110 each side, right?) and items like AC are on both sides of the panel and they all work.
The ad mentioned that it was possible to get other power sources into the system with additional purchase of another item, not sure how this would work with my Inverter.
Currently the inverter is hooked directly to a few outlets that are separate from the breaker panel.

[JackConrad]

To confirm 240 volts, put an AC volt meter on the 2 hot legs of your main panel. If it is a 240 system, you will see 240 on your meter. If it is 120 volts, you will see 0 (120 requires the other lead on the neutral).  Jack

[oldmansax]

I made my own.

I used two 100A, 3 phase contactors with 110V coils, easily available on eBay or at your local electrical or HVAC supplier. Wire the shore power to the input of one (hot-neutral-hot) and the genny to the input of the other the same way. Tie the outputs of the two contactors [ make sure you wire it the same way (hot-neutral-hot OR what ever you want to use just do it the same for all!!)] and wire that to the input of your main panel.

Control wiring: tie one side of the control coil to the neutral on each respective contactor. Purchase a double pole, double throw toggle switch (on-off-on, 6 lugs on the back) rated for 110V and minimum amps from auto parts store or electrical supply. Make sure to check it is rated for 110V.

Pick up 110v from the INPUT (incoming voltage) of #1 contactor to the center lug of your toggle switch on pole #1. Connect the BOTTOM lug of pole #1 to the other side of the coil on contactor #1

Pick up 110v from the INPUT (incoming voaltage) of #2 contactor to the center lug of your toggle switch on pole #2. Connect the TOP lug of pole #2 to the other side of the coil on contactor #2.

FUSE EVERYTHING PROPERLY!

The beauty here is you cannot energize either circuit unless that circuit actually has power. The switch can be remotely mounted  inside the bus. I like mine specifically because all the heavy cables are outside but I can start the genny from inside & switch on the power. That's nice if you lose shore power in the middle of a storm or if the parks power has problems in the middle of the night.

You can also add meters, indicators, bells, buzzers, or flashing lights to your liking.

Have fun!

TOM

[TomC]

I used 4-50 amp breakers. Two for shore power and two for generator power with a metal plate slider in between that only allows operation of either/or but never both at the same time.  My inverter loads have a separate breaker box.  Good Luck, TomC