Generator outlet a good idea?

Split from General / Technical for discussion of anything electrical, electronic... 12v, Inverter, Satellite, Headlights, flashlights etc.
Post Reply
chin_k
**Forum Contributor**
Posts: 2257
Joined: June 26th, 2017, 9:38 pm
Location: Southern CA

Generator outlet a good idea?

Post by chin_k »

I am redoing the automatic transfer switch junction box since I am going to convert the shore power cable to a twist-lock. I am wondering if it is a good idea to add a 30 amp outlet for the generator too? The idea is to use the genset if I need to use it as emergency power for the house. I can either add the outlet near the genset, but I don't see a good spot for it. Let me know if there is a better alternative, or I should work on something else instead.
2000 Concourse dinette, on 1999 6.8L Ford E350 Triton V-10 Chassis
User avatar
Scott
**Forum Contributor**
Posts: 608
Joined: October 12th, 2015, 5:54 am
Location: Santa Cruz

Re: Generator outlet a good idea?

Post by Scott »

My rig did not originally have an automatic transfer switch. There was just a generator-powered 30 amp outlet in the cord storage area to plug into when generator was needed. Dead reliable, but I had to go outside to switch over.
1994 Premier
User avatar
Blue~Go
Senior Member
Posts: 3716
Joined: July 31st, 2014, 1:01 am
Location: 1999 Concourse

Re: Generator outlet a good idea?

Post by Blue~Go »

Another idea that can work depending on your system and needs. Taking out the Brown Box (which I did) meant that I went with a separate marine type charger, and also meant that the DC and AC fuse blocks need to be accounted for, plus source selection (handled in the brown box with an automatic transfer switch).

I didn't really need an automatic transfer switch (no auto-start generator or anything like that), so I went with a marine type AC panel that incorporated a manual source selector and the regular AC circuit breakers. The way it works is that there is a "main" double-pole breaker for each power source (in my case, generator and shore power) and then the breaker panel is made so only one can be switched on at a time. Hence you have to choose *either* generator or shore power on the panel. I like that it's completely simple, robust, and easily visible (of course so are separate cords/sockets).

Here (below) is a photo of the panel I chose:
Blue Sea 8467 sm.png


You can pretty much see how it works: There is a black "lockout" slide that has to cover one of the sources in order for the other one to be flipped on. Simple and manual. The two main breakers in this case are 30 amp, as original. You can see they only have two of the regular breakers installed: You can of course add the other two, and they come in different amperages. They also supply a selection of labels. This is a typical way to handle the AC panel on a boat.

I don't think they make this exact one anymore, but you can still get panels that function similarly. This worked out well for my Chinook because there are two main sources, and four breakers, just like the brown box had. There are also fancy (and nice) rotary switches, but since you still need main breakers it's another thing to buy and takes more space/wire/etc. With this type of panel it's efficiently all in one. Marine breaker panels aren't the cheapest way to go though.

You may have a slightly different situation if you have three sources (i.e. shore charger, generator, and separate inverter that you want to power your same AC outlets). OTOH, an inverter/charger will just count as one source. I don't have either of those situations, as I only have a simple stand-alone inverter that has its own outlet, so that's on the DC side.
1999 Concourse
chin_k
**Forum Contributor**
Posts: 2257
Joined: June 26th, 2017, 9:38 pm
Location: Southern CA

Re: Generator outlet a good idea?

Post by chin_k »

Great info, Blue. I wish there is such a thing as a 3-source auto transfer switch. I had look into adding the inverter as the third source, but there is no clean way of doing it. I think I am just going to go with adding the twist-lock for now, and leave an extra wiring there for the genset outlet until later, and leave the breaker panel the way it is. Once I get more utility out of the rig, I will spend more effort in the upgrade. We suppose to go for a camping trip this long weekend with a group of friends, but other things came up, and we had to cancel.
2000 Concourse dinette, on 1999 6.8L Ford E350 Triton V-10 Chassis
User avatar
Blue~Go
Senior Member
Posts: 3716
Joined: July 31st, 2014, 1:01 am
Location: 1999 Concourse

Re: Generator outlet a good idea?

Post by Blue~Go »

I don't really know much about auto transfer switches. There are multiple pole manual selector switches that will do what you are speaking of (not cheap though). I think I get the problem because I just went through the same thing with my buddy's new rig. The old one had a combo inverter/charger, and since they have an internal transfer switch, it all worked with the panel I showed (only using the shore/gen sources) and all the AC outlets were powered by the inverter/charger as well.

But on the new rig he went with a simpler system, with just a stand-alone smaller inverter and a separate good charger. When we went to figure out how to switch things (because of course the brown box had to go.... it's tradition :D), we realized that, hmm, yeah, with the inverter and charger being separate beasts, we couldn't use the same simple way to keep things from being connected when you didn't want them to be (I'm more of a DC person, so have to really sit and think it through with AC). We knew there could be a way, but he said no, let's just keep it simple, that's my goal here. So we did just a few separate inverter outlets to be used when boondocking, and then just went with the two AC sources (shore/gen) manually selected. When under shore or gen, all the AC outlets work, as per normal.

However that said, with a multiple pole rotary switch, that can be overcome and you'll always only have the source you want to and no "sneak in" sources you don't want. But he chose not to. It's more complicated, more expensive, and when it came down to it, while it would have been mentally satisfying to have all the AC outlets work for everything all the time --- after thinking about it, he really doesn't use AC power very often when boondocking, and a couple of tiny inverters (like for water pik in bathroom), plus using the outlet on the inverter itself (say for a minute of vacuuming) is perfectly fine. So, as usual, there is rarely only one "best" way :)
1999 Concourse
chin_k
**Forum Contributor**
Posts: 2257
Joined: June 26th, 2017, 9:38 pm
Location: Southern CA

Re: Generator outlet a good idea?

Post by chin_k »

If I have time, I may get one of those rotary switches and use it to manually switching between genset and inverter, as well as disconnect the converter/charger when the inverter is on.
2000 Concourse dinette, on 1999 6.8L Ford E350 Triton V-10 Chassis
chin_k
**Forum Contributor**
Posts: 2257
Joined: June 26th, 2017, 9:38 pm
Location: Southern CA

Re: Generator outlet a good idea?

Post by chin_k »

This is related to two other posts. viewtopic.php?f=8&t=912 and viewtopic.php?f=4&t=898

My Chinook has the old shore cord that attached permanently. I pulled the whole cord out and replaced it with stranded 3X10 cable. I added a twist lock adapter to the old cord. Here is what it look like inside the box. As you can see, I also added the generator outlet on top of that. I am looking for some kind of cap to cover the outlet, but don't know if such thing exists.
(Sorry if the picture is rotated.)
Edit: I will add a new floor to hide the cord on the carpeted area, but I have other things to do first.
Attachments
twist lock inlet installed on particle board for test fitting
twist lock inlet installed on particle board for test fitting
installed twist lock inside the electric service box.  Notice the cut out on the bottom to fit the cords.
installed twist lock inside the electric service box. Notice the cut out on the bottom to fit the cords.
2000 Concourse dinette, on 1999 6.8L Ford E350 Triton V-10 Chassis
Post Reply