Generator to cord switching?

[Tom Y]

What are you guys putting in to switch between the gen and cord? I had a 110 panel in my last rv that had 2  220v breakers wired together. 1 to the gen and 1 to the cord, if 1 was on the other was off. Any ideason this ?  Thanks Tom Y

[H3Jim]

I put in an Iota ATS-50R  automatic transfer switch, that senses when there is power from the generator.  It switches both legs of a 50 amp, 230 volt.  I bought this on a recommendation when I was still figuring things out.  It is convenient, I don't really even have to think about it.

Now I think I'd just have a plug.  I could plug the wires that go to the coach elec panels into an outlet that came from the generator, or into an outlet from a power pole. Easy, simple, fool proof.

[JackConrad]

    We have the automatic transfer switch (50 amp) in our bus. I wired an eagle last week using the very basic simple system: 2  50 amp receptacles mounted on the wall in the bay. One from the shoreline and one fron the generator. A 50 amp plug on the end of a cord from the load center. He plugs into whichever power source he wants to use. Like everything else, both have advantages and disadvantages. Do what works best for you and your type of use of the bus.  Jack

[TomCat]

Iota ATS-50R automatic transfer switch for me. Around $100 and found almost anywhere, even on the e place.

Jay
87  SaftLiner

[H3Jim]

If you 're goig to be ouside plugging in to shore, its pretty simple to just plug in a la Jack.  The disadvantage of the automatic one is that it does not switch neutral or ground, just the hot ones, so another way must be found to switch.  You dont want to have two neutral to ground bonds and the manual way works very well. As has been beat to death many times on these boards, the bonding of neutral to ground is an important issue. 

I'm not really sure the manual way has any disadvantage at all.

[DavidInWilmNC]

If you 're goig to be ouside plugging in to shore, its pretty simple to just plug in a la Jack.  The disadvantage of the automatic one is that it does not switch neutral or ground, just the hot ones, so another way must be found to switch.  You dont want to have two neutral to ground bonds and the manual way works very well. As has been beat to death many times on these boards, the bonding of neutral to ground is an important issue. 

I'm not really sure the manual way has any disadvantage at all.

Jim,

Most of the automatic switches I've seen, including the Iota that I have, do switch ground and neutral.  I can see a couple of benefits of the automatic switches.  Several places we go have 20 and 30 amp hookups.  If I need more current, I can just start the generator and it'll switch over to it after a delay.  The other benefit is the delay itself.  I put one of these switches in a friend's RV.  She had problems using the roof A/C on generator.  This was due to trying to start the generator with the A/C turned on.  Her option was to pull over somewhere, turn off the A/C, start the generator, wait a bit, then turn the A/C back on.  She travels by herself a often and says this made using the A/C more convenient / possible.  I see the manual two outlet method having only one benefit - simplicity.  If my switch goes bad, it's just a matter of connecting the correct source wires to the leads going to the breaker panel.  This is located in a cabinet in the kitchen, so it's fairly accessible.

David

[Sam 4106]

Hi DavidInWilmNC and H3Jim,
I believe there are errors in both of your posts. David, since your transfer switch is so accessable would you look at it and verify that your ground is switched? As far as I know you NEVER switch a ground. H3Jim, would you also look in your transfer switch to verify that the neutral is not switched? In my transfer switch (Magnatec) the ground bar is bolted to the metal enclosure and the enclosure is bolted to the body of the bus. There are two 3-pole contacters that switch both hots and the neutral. Since the neutrals are switched there is not a dual neutral/ground bond as only one contacter is closed at a time.
If either of your Iota transfer switches operate differently than mine, would you please post the scematic?
H3Jim, you said about your automatic transfer switch, "It is convenient, I don't really even have to think about it." and that the plug method is "Easy, simple, fool proof." What can be more "Easy, simple, fool proof." than automatic? In addition you have the advantage of being able to start your generator and powering you bus without having to stop to switch plugs, as David points out. If none of this makes sense I hope someone more knowledgeable than I am will explain it to us all.
Thanks, Sam 4106

[JackConrad]

My Iota 50 amp switches both hot leags and the neutral. Grounds are not switched. 4 terminals from Generator, Shoreline, and Load Center, bot only 3 are switched  Jack
PS: switch was purchase on the e place for less than $100

[Nick Badame Refrig/ACC]

Ditto,

My 50 amp transfer switch switches nutrals and both legs

Nick-

[Tom Y]

Thanks for the replys. Now another question. What about your inverters? I would not want to heat up the male end of a plug, or feedback into the gen. Whats the easy way out on this. Thanks To all.  Tom Y

[JackConrad]

If you have "pass through" type inverter such as Trace, Heart Interface, or Xantrec. Run wiring from a dedicated circuit breaker in your main load center to the input of the inverter. Run wiring from the inverter output to a separate load center. This sub panel will feed all circuits that will be powered by the inverter. This is the way my Heart Interface manual recommended connecting our inverter.  Jack

[Nick Badame Refrig/ACC]

Hi Tony,

If you bring all your power into the transfer switch first, [gen set, land line] your transfer switch will default to genset. Then when you plug in

your land line, that power will energise the contactors in the switch within a milli second, to divert the power flo. So, when you are Not pluged in,

your land line male end, will always be dead. [no current]. Then after your transfer switch, should be your inverter, then your electric panel.

Some will have vairations from the transfer switch on but, basicly the same path.

Good Luck
Nick-

[Nick Badame Refrig/ACC]

Sorry Jack for stepping on your foot! Lol
Nick-

[JackConrad]

There are several ways to wire the inverter. It can be done as Nick said also. If wired in before the load center, it needs to be a big inverter as all 120 volt load has to pass through it. Wiring this way will allow AC's and everything else to be run off the inverter. The downside is, if you are plugged in, with ACs running while you are out enjoying yourself and the shorepower fails, you will come back to dead house batteries.  Jack

[TomC]

I used a 4 circuit breaker box that is wired to run the power through the circuit breakers to the bus bar of the breaker box (doesn't really matter which way you wire it since it is AC current).  So two of the circut breakers are from the generator and the other two are from the land line.  I made a sheet metal cutout slider that only allows two of the switches to be used at a time-with the two switches from the generator barred together.  The wiring is- the power comes in from either the gen or the land line, have the circuit breakers closed for whichever is used, goes to the bus bar of the box where #6 wires lead it to the main circuit breaker box.  There another 30 amp breaker feeds through the inverter that is wired to another circuit breaker box with my inverter powered items (plugs in the kitchen, microwave/toaster oven, front TV, rear stereo, bath plug, bath heater, plugs in under storage).  All is wired straight 120v, so I don't have to worry about balancing loads.  Course that restricts me to only 50amps of land line coming from one leg only.  But can run two A/C's with power to spare.  Works for me.  Good Luck, TomC