| Author |
Message |
Brian Brown (Fishbowlbrian)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 18, 2005 - 7:53 pm: | |
Here's a shot of my new 4106’s transfer panel, as built by the converter/ Seller. [Sorry about the pic size for anybody on dial-up… but I wanted everyone to see it clearly.] I wanted to familiarize myself with everything the converter did, so I didn’t kill myself or a loved one.
My electrical experience so far has been relegated to house wiring of branch circuits (110 & 220), so please excuse some of my ignorance in these RV wiring matters. I wanted to ask if this transfer panel looked right to some of you elec. gurus. I’m still learning about ground bonding, phases, etc.
The genset wiring comes in from the top left, the shore cord from the bottom, and the feed to the coach thru the top. The receptacle at lower left? Some sort of buddy plug, is all I can figure, since it’s hot no matter what position the lever is in.
Now, on to the setup… the shore cord was listed by the Seller as a “50a park power” setup, but I don’t see how this is possible over the two conductors and ground coming in. Would that be 110v 50a on a single leg?? If so, then the shore cord seems “under-gauged” for that.
For a split leg, 110v 25a/25a setup, it seems like I’m missing another hot leg at the shore cord. I realize that without the pigtails showing at the genset, we’re missing part of the puzzle here. I can get that tomorrow.
Then, at the transfer box, the red conductor becomes ground (a code violation, methinks), since its tied at the bus bar to the green conductor.
Soo… black is hot, white is neutral, just like in house wiring. Red is ground, looks like. The neutral is never bonded to ground (except at the park receptacle).
Look right to you?
Now, Somewhere I have a nice PDF of Scott Whitney’s elec. diagram. Anyone else care to share theirs?
Thanks, as always!
Brian Brown
Longmont. CO |
Bill moldenhauer (Hotrodbill)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 18, 2005 - 8:24 pm: | |
First off electricity does not care what color the wire is
but as a good practice black and red should be hot with white as neutral and green is always ground
But the whole bus could be wired with this (new)code so be careful if you decide to switch wire colors around
from the picture the shore cord looks to small
for 50 amp
But in this case it looks like you have 120v service from generator and shore power
and at 30amps shore service the wire should be at least #10
from the picture it looks ike #12 wire |
Chuck Newman (Chuck_newman)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 18, 2005 - 9:13 pm: | |
Brian,
I agree with Bill on all points. I would recommend getting some green colored electrical tape and run two or three wraps on the red wire so it indicates ground. The NEC allows that. As Bill said, someone else looking into the panel needs to know what each wire is.
Caution here: the shore cord was listed by the Seller as a “50a park power” setup. Based on wrong color coding and non-matching wire size in the panel and the cord, you can presume other errors exist. What exactly do you have for a plug. 30 amp configuration, or a 50 amp plug with only one leg connected. You really need to trace your voltages from the post and through the panel to know for sure. The actual hookup of the panel is OK for a 30 amp service.
Also, what is the rating on the generator breakers. That will give a clue as to what the previous owner was trying to do. What does the transfer panel feed?
I would clean up the connections on the buddy plug. At least from the photo, looks like a couple leads are pretty close.
Chuck Newman
Oroville, CA |
mclough
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 18, 2005 - 9:55 pm: | |
on my old genset setup , i had a similar configuration. when on getset power i had 2 legs of 110. when i threw switch to shore power i had to move one of the wires to the middle to have the same 2 legs. if i didnt move the wire i would end up with 1 leg of 110.
i hated this set up, i hated to have to get down there and throw the switch especially when night or raining. when i got new genset i had them remove this setup and went with an automatic switching device.It is awesome and i dont have to leave coach to switch.
morgan clough |
Sean Welsh (Sean)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 19, 2005 - 2:36 am: | |
Brian,
I agree with most of what has already been posted. Let me add a couple points:
1. This is clearly a two-pole switch. It appears to be switching hot and neutral. In order to have a "50 amp park power" setup, you need at least a three-pole switch, to switch two separate hots and the neutral.
2. I can read on the red wire that it is type THW but I can't see the gauge marking. It should be marked somewhere on the wire, but, from the photo, I would guess that most of the wiring on this switch is #10, which is good for 30 amps max, depending on conditions. For 50 amp service, you need to use #6. To upgrade, you will need to run new wire all the way from the shore cable, through the transfer switch, and to your main load center.
3. While the main wiring appears to be #10, the shore cord itself is clearly a smaller gauge, probably #12. #12 is good for at most 20 amps, again depending on conditions. In this configuration, I would not run more than 15 amps through it.
4. The reason why your ground wire is red is because the idiot who wired this setup used a type of cable (armored, BX type) made for 240-volt circuits with no ground (actually, the jacket of the cable is supposed to be the ground in its intended use, but that's not code for this purpose), instead of getting the right cable, made for 120-volt circuits with grounding conductor (which would have a white wire, a black wire, and either a green wire or a bare copper wire). So they simply repurposed the red wire as ground. This actually meets code, so long as there is green tape around the last few CM of jacket (I'd have to look up the exact amount required), but clearly, they did not even bother to do that.
5. The change of gauge from the shore cord to the transfer switch is a major code violation (unless there is a separate, properly rated fuse or breaker on the shore cord, which you said was unfused).
Based on all of the above, I would suggest that the entire electrical system in this coach is suspect, and I would go over it with a fine-tooth comb.
Incidentally, it is a criminal violation in many states, and certainly cause for civil remedy in all states, to sell a housing product containing code violations. So you probably have significant legal recourse against the seller to remedy these faults. On top of that, he lied to you outright by saying this was a "50 amp park power" setup.
Lastly, you asked about wiring diagrams, and there are several on my web site at http://OurOdyssey.US (click on "the bus" and follow the thread to the electrical section).
HTH,
-Sean |
John that newguy
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 19, 2005 - 8:46 am: | |
That picture represents a typical 30 amp RV service. Did the
guy split the system elsewhere to allow for 50 amp service to
be used? A second power cord to plug in and use for the devices
not connected through a dead side of the box?
Guys have modified RV wiring in that manner to be able to run
both AC units using two separate shore lines. Some had even
added "transfer switches" to be able to put both AC units back
into the circuit if being run from the genset. The transfer box
would look like yours, since it's only to break or combine the
"other circuit".
Why don't you call the guy and get some better info from him.
There may not be any need to undo it all. |
Jtng
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 19, 2005 - 8:51 am: | |
Incidentally Brian... Your comment:
"I realize that without the pigtails showing
at the genset, we’re missing part of the puzzle here. "
Most often one AC unit is wired to one leg of the genset
and the other leg goes to the panel to route to the other
AC unit and all other circuits.
In that case, the guy's box makes sense; it's typical RV. |
Brian Brown (Fishbowlbrian)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 19, 2005 - 11:38 am: | |
Thanks for some insight, guys. I'm heading out there again this morning to resurrect (hopefully) the genset. I'll take a look at the pigtails in the genny and see if they all route to the xfer switch or if he's pulled a leg out to another panel somewhere. I'll also check gauges on the wires.
I'll keep ya' posted,
BB |
James Maxwell (Jmaxwell)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 19, 2005 - 12:29 pm: | |
The feed wire out the top appears to me to be #8 (it is a single digit after AWG). One more fault. Shore ground is tied directly to generator ground, which may go to chassis somewhere at the genset. You are going to get tickled when shore plugged and you are going to trip any GFI u plug into. |
Sean Welsh (Sean)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 19, 2005 - 1:39 pm: | |
Jim,
You wrote "Shore ground is tied directly to generator ground, which may go to chassis somewhere at the genset," implying this is a problem.
Uhh, this is *required* by code -- all grounds need to be bonded together and bonded to chassis. I don't see a problem here. The situation where a problem comes in is when the grounds are bonded to the *neutral* both in the coach and at the shore line. Since this switch is clearly switching neutrals between genny and shore, that should not be an issue (though, given the boneheaded installation, this problem may very well exist elsewhere in the coach).
-Sean |
Brian Brown (Fishbowlbrian)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 19, 2005 - 7:22 pm: | |
Well, I was out at the coach again today. I'm now rebuidling the carb on the genny... whoppie! But I digress...
The shore cord is a 10/3 and clearly likewise labeled as 30A. The rest of the wires are curiously #6. Maybe the genny can push out enough amps to merit the gauge change, but it seems "not quite right" to have an undersized shore cord.
The main disconnect inside the coach is a 50A, feeding two panels. I need to take them apart to see if we have split legs in there, but I can't see how that will work, since the xfer switch is clearly just sending hot, neutral, and ground up. I didn't find any other genny leads implying a (L1 L2 N G) split-leg 120v system.
Can the genny send 50A on a single leg? Even if, the coach might try to draw more power through the shore cord than safely allowed on a 30A cable, assuming one found a 220v/50A plug to pull one leg of power off of. [Scratching head now...]
It's strange indeed. Looks like I'll have to check amperage/gauges in all my branch circuits, too. There's two 30A breakers in the panels that may be fed by inadequate-sized wire (needs #10 or better). Hopefully, he didn't wire the 20A's with #14. Sigh...
I guess this is the price I pay for "saving myself some work", LOL.
Thanks for your help, guys!
BB |
Sean Welsh (Sean)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 19, 2005 - 7:54 pm: | |
Brian,
Well, just goes to show how hard it is to judge sizes on a photo with no "reference" points. (In the future, by the way, consider putting such a reference in the photo, such as a US coin, or a pencil or some such item.)
If the wiring is all #6 (except, as you note, the shore cord) then your transfer switch is set up for 50 amps, which may indeed be what your genny can produce. Note, though, that "50 amp park service" is really 50 amps times two legs, and you have only a one-leg system.
The shore cord presents more of a problem. If this is, as you say, #10, then it is a "standard" 30-amp RV shore cord. Properly connected to a 30-amp shore receptacle (which would be protected by a 30-amp breaker at the post), this setup poses no hazard -- any attempt to draw more than 30 amps through the system will pop the shore breaker.
Where the problem comes in is if you should buy (or make) and use one of those "dogbone" adapters to plug into a 50-amp shore receptacle. (Sometimes, the only receptacles available on a campground post will be a 50-amp and a 15-amp, with no separate, fused 30-amp receptacle.) These dogbones simply connect the hot leg of the 30-amp "outlet" to one of the two hot legs on the 50-amp plug -- they contain no internal circuit protection.
Since your main breaker inside the coach is a 50-amp, you now have the situation where you can be drawing loads higher than 30-amps, and all the way up to 50 amps, through a cord made of #10 wire that is only good for 30 amps. The consequence of this would be overheating of the cord, possibly to the point of starting a fire.
There are two easy ways to solve this:
1. Replace the shore cord with a cordset consisting of #6 wire. This will let you plug into either 30-amp or 50-amp service without danger. (Bear in mind, with this transfer switch, you will still only be able to run one hot leg into the coach, so you will not get the full benefit of a true 50-amp setup.)
2. Wire a 30-amp breaker into the circuit between the shore cord and the transfer switch. This will ensure that you can not inadvertently pull more than 30 amps through the shore cord, but will still allow you to pull 50 amps through your main panel when running on generator (assuming your genny can put out this much).
There are, of course, many other options up to and including replacing the transfer switch with a 3-pole model and putting in a 240-volt/50-amp four-wire service, but the two above are the most straight-forward and least expensive.
And, yes, some generators can and do put out 50 amps on a single leg. My own generator, which puts out a whopping 70 amps on each of two legs, can be easily re-strapped to put out a gargantuan 140 amps on a single 120vac leg.
-Sean |
Richard Bowyer (Drivingmisslazy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 19, 2005 - 8:01 pm: | |
Is it possible that the switch is actually switching two hot legs? It is generally not normal to switch the neutral. The genset could also be wired for 240/120 volts.
Richard |
ChuckMC9 (Chucks)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 19, 2005 - 9:55 pm: | |
Hey "Third Time's a Charm" Brian -
It could be that in the days that coach was used there was no need (nor availablity of service) for a 50A shore cord.
I think it's time to pull out your meter. Richard could also be on to something, which would make for way heinous wiring.
Interesting thread, and as always I learn a lot from Sean and everyone. |
James Maxwell (Jmaxwell)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 19, 2005 - 11:03 pm: | |
Sean: You are correct. I was sitting here thinking neutral and looking at the ground wires; my only explanation. Considering that I was also changing oil in the bus tdy. and after pouring abt. 3 qts. in the fill tube realized that I had not put the plug back in the pan. Is it time to hang it up, pack it in? |
Marc Bourget
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, February 20, 2005 - 12:21 am: | |
Join the club, James, I did about a month ago! |
James Maxwell (Jmaxwell)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, February 20, 2005 - 1:38 am: | |
Which Marc, packed it in and hung it up or left out the drain plug? While muttering to myself while cleaning up this mess in my bus port I just couldn't believe that I had done such a dumb thing. Fortunately, I didn't go start the engine to check for leaks before I got it filled. Sure hope I remembered to tighten the filters!!!!!!! No chance, I went over the whole damn thing before I touched those keys!!! I now have proof that it takes nearly 9 gallons to fill a 8v92 w/filters. |
Brian Brown (Fishbowlbrian)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, February 20, 2005 - 3:00 am: | |
Thanks, guys.
Sean, I'll probably just fuse the shore cable for now and see on my first trip how many places I camp even offer 240v/50A service. The 120v/30A should run 1 A/C and my other A/C appliances. It's just getting my second A/C to kick on that's the tough part with 30A.
I'm going to go through the rest of the coach and check wiring after I get the genny fired up. I don't have any shore power available where it's parked, so the genny is the top priority. I need A/C to run my pancake compressor so I can check my airbags and see which ones are leaking in order to get it aired up and moved closer to home.
Thanks again,
Brian |
Marc Bourget
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, February 20, 2005 - 4:48 am: | |
The LOTDP club! What a coincidence, within days of my 55th. Not the type of (senior) moment to associate a 55th "first" with. |
Tom Caffrey (Pvcces)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 05, 2005 - 9:55 pm: | |
Richard, in RVs and other structures with the possibility of receiving power from shore or on-board generator, the neutral must be switched to prevent improper bonding of the neutral and ground.
The inverters that we have been using do this, as well. When the inverter is on, the inverter provides the neutral bond to ground, but when shore power is present, the transfer relay disconnects that bond.
Since the ground paths must remain connected together, the neutral must be shfted to the power source in use at the time.
Sean, do you bother attempting any type of earth ground when you are running on the generator? It seems to me that this is a real tough nut to crack in most circumstances. I haven't figured out any sensible way to do this, yet.
For what it's worth.
Tom Caffrey PD4106-2576
Suncatcher |
Sean Welsh (Sean)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 06, 2005 - 12:28 am: | |
Tom,
If, when you say "earth ground" you mean exactly that, which is to say an actual connection to the earth, the answer is no, I do not. Code does not require this, as long as all the loads are also on-board and the AC ground is connected to the chassis frame. If, however, you power loads external to the coach from the generator, then the earth ground needs to be in place. This can be achieved by bonding the vehicle frame to a water pipe or driven rod.
Also, FWIW, my inverter does not provide a ground/neutral bond relay (Trace SW series), so I have implemented this externally.
To solve many of the thorny problems associated with making a 120-volt, single-phase inverter (with built-in transfer) work seamlessly in a 120/240 environment (shore and generator) and also take care of ground/neutral bonding and some energy managment thrown in, I ended up building my own custom Automatic Transfer Switch. I have a lengthy and arcane write-up and diagram of this on my web site at:
http://ourodyssey.us/bus-e-ats.html
-Sean |
Tom Caffrey (Pvcces)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 11, 2005 - 9:43 pm: | |
Thanks, Sean.
Tom Caffrey PD4106-2576
Suncatcher |
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