| Author | Message | ||
| David Evans (Dmd)
Registered Member Username: Dmd Post Number: 283 Registered: 10-2004 Posted From: 173.68.141.86  Rating: N/A |
I was told i need to set up breakers for the gen set close to the gen before the crossover switch and main breaker panel. what did you use for this? And do you also run the nuetral thru a breaker? This is a 240 set up with 4 leads including the ground. I tried to find a box at homecheepo but maybe i have to hit a real electic supply house. Another ? is can the gen set be run if these breakers are switched off, where does the power go if it cant go thru? And the last problem i seem to have (if only it could be the last)is i have continuity thru the ground and the nuetrals on the main panel. And Steve Fessden i want to get an update on yur rockwool insulation project, how it worked out or dident. Thanks everyone. I tried the archives but havent been doing as well with it as i used to. maybe time for a lesson is archives from the boss. | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 734 Registered: 8-2006 Posted From: 64.55.111.6 Rating: N/A |
Dave, A pair of breakers on the HOT LEADS from the generator, installed as close as possible to the generator, would protect against a short in the wires between the generator and the panel, and an overload of the generator. NEVER, NEVER, EVER RUN A NEUTRAL THRU A BREAKER!!! (Or a ground!) Your main panel MUST be wired as a subpanel, or in other words, it CAN'T have the ground and neutral bus bars connected. Look closely at your panel, and see if one of the bars has plastic standoffs on each end, so it is insulated from the box. If so, it must be the neutral, while the other bar should be screwed to the metal box, and be the ground. The continuity between the bars can't be there, and may be caused by a bonding jumper that needs to be removed, or by an appliance, inverter, or generator that has the ground and neutral connected internally. THE GROUND AND NEUTRAL CONNECTION CAN ONLY BE MADE AT THE POWER SOURCE, PERIOD. This means your shore/gen transfer switch MUST switch the neutral as well as the hots. If you have an inverter, it must transfer the neutral and ground also, so only one ground is present at a time, and that ground is the source providing power. Yep, that means while on shore power, the ground point is the campground main panel! The generator won't be hurt by running on an open circuit, as it is no different than having it connected to the whole bus, with nothing turned on? HTH, G | ||
| Cullen Newsom (Cullennewsom)
Registered Member Username: Cullennewsom Post Number: 2 Registered: 2-2009 Posted From: 98.201.161.214 Rating: N/A |
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| Cullen Newsom (Cullennewsom)
Registered Member Username: Cullennewsom Post Number: 3 Registered: 2-2009 Posted From: 98.201.161.214 Rating: N/A |
> I was told i need to set up breakers for the gen set close to the gen before the crossover switch and main breaker panel. Doesn't the generator have a circuit breaker(s)? Does your system resemble this diagram? http://www.smps.us/connecting_generator.GIF > And do you also run the nuetral thru a breaker? No. That's why you have your "crossover switch" And get yourself a copy of "Ugly's Electrical Reference" (available at homecheapo) > This is a 240 set up with 4 leads including the ground. Make sure you get a DPST (Double Pole Single Throw) I like McMaster Carr http://www.mcmaster.com They are not the cheapest, but they have nearly everything, and the have a good website, where things are easy to find. http://www.mcmaster.com/#din-rail-mount-circuit-breakers/=pqhkk I suggest using DIN-Rail mount stuff, home use breakers look to me like they might come un-seated when you hit a bump. > can the gen set be run if these breakers are switched off, Yes. And, "open" is how we refer to switches that are "off" (as in non-continuity) > where does the power go if it cant go thru? Either it finds another, easier path to "ground" (back to the genny). Or it sits there and waits. Think of an air tank and hoses, pressurized, but with all of the valves shut. Or, if you want to get a better idea of what your generator does, find a small motor that isn't connected to anything. Spin the shaft with your hand and note how easy it is. Now connect it's leads together and give it another spin. You should notice that it's harder to spin, that's because it has a load (a short circuit in this case). > And the last problem i seem to have (if only it could be the last)is i have continuity thru the ground and the nuetrals on the main panel. This is not abnormal. It's called "neutral bonding" Here is a page that may help you understand. http://www.roadtreker.com/documents/6CDD2B76E230AFAE657D2549FA725088EFD2E93D.html Here's another page that may help explain more about "neutral bonding" with a nice diagram of an improperly wired system. http://www.highport.com/electricalHazard.php Neutral bonding is one of the reasons you want a full disconnect from your shore power. Have you ever been shocked by an RV? This could be the reason. I'll also recommend Thomas Glover's "Pocket Ref" even though it's so full of "useless" information; that it's hard to find what you want. It does have some helpful guides for wire sizing and the like. I hope that helps more than it hurts. And, I'm not responsible if my free advice causes your cat to get pregnant, or other terrible things to happen. -CN | ||
| David Evans (Dmd)
Registered Member Username: Dmd Post Number: 284 Registered: 10-2004 Posted From: 173.77.233.80 Rating: N/A |
Nice answers guys, if i dont have to "protect" the nuetral i have a box with switches that will work. George i was hoping you would answer and thanks for the tips.Cullen welcome to the board and thanks for info also. I will check out the sites you posted. I dident get anything much done today as it was a cold rain here in NY. The crossover switch does the dissconnects and i checked the panel i guess i will have to check the appliances. I do have a 240 stove top and i read that can be a source of interconnection. If it is what do you do then? I really appreciate the comebacks, Dave. Can a pregnant cat be used as a temporary ground? | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 735 Registered: 8-2006 Posted From: 64.55.111.6 Rating: N/A |
Cullen, I don't want to be picky, but there's a couple of problems with the diagrams you've posted. The first link (smps.us) doesn't disconnect the neutral when the electric meter switch is opened, leaving two ground/neutral bonds when using generator power. (Look closely in the upper left corner, it only switches X and Y, W isn't switched, and the ground/neutral connection at the main panel required by Article 250 of the NEC just isn't shown.) The recommended switch has to be 3 poles, so it can open the neutral as well as the hots. The link (roadtreker) diagram doesn't explain neutral switching anywhere except the little dotted line marked common neutral on the "cutoff switch." It is also a strange and redundant way of doing things, as the transfer switch does the same thing as the cutoff switch? Highport's link and explanation is right on, thats just what can happen when ground/neutral bonding isn't properly done. I don't know how they think it can reach 240 Volts, when line to ground or neutral is only 120, but that isn't the point. An inverter with "feed thru" that automatically does the ground/neutral switching, installed between the shore/gen xfer switch and the main panel would be a lot better arrangement, in my opinion. FWIW, George | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 736 Registered: 8-2006 Posted From: 64.55.111.6 Rating: N/A |
Dave, I started on the answer, then the phone rang, and I didn't get back to this for a while, so that's why my answer immediately above doesn't address your 240V stove. That's the first place I would look, and the chance of success will be high. The generator neutral and ground are together at the gen also... Another thought is to take the neutrals off the bar one at a time, and see which one clears the connection? Again, apologies for being kind of picky, take Highport's advice to heart, and thanks for the vote of confidence! George | ||
| Cullen Newsom (Cullennewsom)
Registered Member Username: Cullennewsom Post Number: 4 Registered: 2-2009 Posted From: 98.201.161.214 Rating: N/A |
Dave, thanks. I'll try to answer your last questions as well as I can. After a few unsuccessful attempts at simply giving a cat a bath (pregnant or not). I'll just say that I don't recommend trying to make a cat do anything the cat doesn't already want to do. Cats do what they want, when they want to do it. And as you might also be aware, they have a special way of letting you know what they don't want to do. The one thing I can testify to is that cats do not want baths. Regarding your stove top Dave. If it were mine, I would do what it takes to make sure that I haven't violated the "single point of neutral bonding" rule, or I would expect trouble. One tool that I have that puts my mind at ease when working with this stuff is my Hot-Rod Safety Screwdriver http://www.tasco-usa.com/hotrod.htm Don't bother with the one from Ideal (home cheapo), it is garbage. One of these will do the same job though. Not as flashy, but they only cost a buck or two. http://www.inspect-ny.com/electric/neontester.jpg Good Luck, -Cullen | ||
| Cullen Newsom (Cullennewsom)
Registered Member Username: Cullennewsom Post Number: 5 Registered: 2-2009 Posted From: 98.201.161.214 Rating: N/A |
George, Dave, No that diagram isn't ideal. But it does show where circuit breakers belong, and how they are normally wired. In regards to the second link, I should have been more clear. I mean to disregard their cartoon http://www.roadtreker.com/images/AE277F99E04E726AB4DE37954257C9499E12461E.jpg And agree that it is kinda funny looking. I'll copy the parts of the second link that I thought were pertinent. > The key here is that you want to be able to interrupt the neutral (white) wire coming from the inverter output in addition to the hot (black) wire. The reason for this stems from something called neutral bonding. And also his explanation of his symptoms at his home with the GFCI. Maybe Highport was talking about single-phase 240. > An inverter with "feed thru" that automatically does the ground/neutral switching, installed between the shore/gen xfer switch and the main panel would be a lot better arrangement, in my opinion. I wouldn't disagree with you on that one either, but sometimes we have to work with what we've got, rather than what we want. No worries, or hurt feelings, and even if there were, safety and clarity are more important than feelings. Cheers, Cullen | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 737 Registered: 8-2006 Posted From: 64.55.111.6 Rating: N/A |
Cullen Just like the Highpost story, what we're after here is safety. Your last line says it all, that's just what it is, here too! Regards, George | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 703 Registered: 10-2006 Posted From: 66.82.162.16 Rating: N/A |
Instead of a switch , and the usual problems with switching grounds and neutrals , some folks prefer a plug inside that is the coach supply and 2 or 3 sockets of the right size. Simply plug in to the socket which is currently energized. Works every time , no maint , AS seen in an old Blue Bird Wanderlodge I camped. WAS in the clothes closet , EZ to get to , even in the rain. FF | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 738 Registered: 8-2006 Posted From: 64.55.111.6 Rating: N/A |
FF, I can cope with a female socket connected to the shore line, and another connected to the generator. By "...2 or 3 sockets of the right size." I assume you mean the third one for the inverter? If so, what happens after boondocking for a few days, house batts are down, its warm inside, so you want some A/C, you fire up the gen and move the plug? (I have been eating a lot of chips with GUACAMOLE dip!) G | ||
| David Evans (Dmd)
Registered Member Username: Dmd Post Number: 285 Registered: 10-2004 Posted From: 173.77.233.80 Rating: N/A |
Hey guys just got in and its cold and dark so still not back out to the set yet. Fred, i always was going to go with the kiss way and do the plug into the main panel from the gen set or shore power but Justin at Wrico talked me out of it. They see lots of loose plugs from vibration and wear causing problems so i went with the auto switch. Time will tell. I do have to admit the wiring is pretty straight on the transfer switch, all terminals labeled where even an electrical maroon can do it. Ha! | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 705 Registered: 10-2006 Posted From: 66.82.9.58 Rating: N/A |
I do have to admit the wiring is pretty straight on the transfer switch, all terminals labeled where even an electrical maroon can do it. Ha! The problem comes when folks wish to install an "Automatic Transfer Switch , and a gent on your line starts a noisemaker that feeds the campground circuit. Or a lightning strike nearby blows the "Automatic " brain. Have never seen those big house plugs get loose ,ours just push down to get in , so no loads, BUT if that's your fear , marine plugs and sockets screw together and are watertight. Although I would not put them in the shower to save space!! 3 Marine sockets and a 50A 240V Hubbel plug might cost more than the dumb switch , but would have lowest chance of failure. FF | ||
| David Evans (Dmd)
Registered Member Username: Dmd Post Number: 286 Registered: 10-2004 Posted From: 173.77.233.80 Rating: N/A |
Ok,we had ignition and 110 power just at dark thirty last night. Not enough time to see about the cross connections on ground and nuetrals or to test 220 just fired her up and saw the light bulb lite and no smoke so decided better get some supper. I used a 7x13 breaker box with the two legs going thru seperate breakers.There is room for a 15 amp breaker off one of the gen legs in this box and i was going to run from this breaker to the squirrel box fan for the radiator so as to make it come on when the gen starts and supplies power. Good/bad? and if this is good or at least an option, where do i pick up my nuetral for this? tie into the gen nuetral seems wrong. But so does pulling off the main panel (they are side by side). Thanks againn in advance. this would be a good day to play hookie, but we cant. Sun and only 26 out with a high on 38-44! woohoo. | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 757 Registered: 1-2003 Posted From: 72.171.0.143 Rating: N/A |
David, Code (and safe practice) requires that you use a two-pole or handle-tie breaker for the output of your 120/240 generator. Loads connected to the generator, including your proposed fan, must have hot, neutral (if any) and ground all connected to the generator. This is why you've been told you need a transfer switch that accommodates both hots and the neutral. Never, ever connect current-carrying wires of separate systems together. That includes the neutral. -Sean http://OurOdyssey.BlogSpot.com | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 740 Registered: 8-2006 Posted From: 64.55.111.6 Rating: N/A |
3 sockets, one each for the inverter, gen, and shore? What happens after boondocking with the above proposed 3 socket system and we run the gen for whatever other reason, and to ostensibly to charge the house batteries? What happened? Well all the 120 VAC was available, if the plug was moved back to the gen socket, but I still haven't figured out how the inverter could charge the batteries without having an INPUT connection???? The answer I was hoping for was: "You've got to connect the male plug to the INPUT of the inverter, and the inverter OUTPUT to the main panel, and no 3rd socket." Then, if the inverter has the proper ground/neutral swithcing, all will be well. G |