| Author | Message | ||
| Pete/RTS Daytona (Pete_rtsdaytona)
Registered Member Username: Pete_rtsdaytona Post Number: 538 Registered: 1-2005 Posted From: 97.104.21.0 Rating: N/A |
Hi All Sean Welsh - can you shed some light on this subject. I think I understand the whole Neutral to ground BONDING isuue - To me it means that the ground to neutral connection (bond) must be always at the source of the aC power being supplied - If your on pole power then the bond should be at the pole - (and no place else) if your on Inverter power - then the inverter should have the neutral to ground bond - and when the inverter is not supplying power that bOND MUST BE RELEASED same with the Generator BUT HERE IS MY QUESTION - do I tie the GROUND RAIL in my AC BREAKER box to THE BUS FRAME !! what size wire - is it required by code / safety I relize that things like my Air conditioner and electric hot water heater will probaly have a ground wire to FRAME type conection inside the unit But therein lies the rub - do I need to RE-INFORCE this ground to frame connection with a solid connection at the breaker box Pete RTS/Daytona I | ||
| Len Silva (Lsilva)
Registered Member Username: Lsilva Post Number: 209 Registered: 12-2000 Posted From: 24.164.20.23  Rating: N/A |
I know you asked Sean, but I'll pop in here. The short answer is yes. Every electrical cabinet should be bonded to the frame of the bus. The generator, the inverter, water heater etc., etc. should be bonded. This can be done by physically bolting it to the frame or using a bonding wire, bare or green #8 will do. | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 792 Registered: 1-2003 Posted From: 72.171.0.140 Rating: N/A |
Pete, Len is correct on all counts. Any and all distribution panelboards must be directly bonded to the frame with a minimum #8 wire unless the panel itself is securely bolted, welded, or riveted to the frame. Aluminum is prohibited for the bonding wire if it attaches in a place exposed to the elements, where corrosion can occur. And, of course, each panel, box, outlet, etc. must be bonded to the electrical grounding system. The code goes further -- basically anything metal in the coach must also be bonded, e.g. pipes, air conditioning ducts, etc. If these are bolted to the frame anywhere, that covers it, otherwise they should be bonded to the frame with a #8 bonding strap. You are correct in your understanding of ground-to-neutral bonding and that it must occur in one and only one place in any given electrical system. -Sean http://OurOdyssey.BlogSpot.com | ||
| Pete/RTS Daytona (Pete_rtsdaytona)
Registered Member Username: Pete_rtsdaytona Post Number: 539 Registered: 1-2005 Posted From: 97.104.21.0 Rating: N/A |
Len All my appliciance are bonded to the frame My question is - should I run a wire from FRAME GROUND to my BREAKER PANEL ground BAR ?? | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 793 Registered: 1-2003 Posted From: 72.171.0.140 Rating: N/A |
Pete, Guessing you were typing while I was. Short answer is "yes" unless the breaker panel itself is bolted, welded, or riveted to the metal frame of the bus. The ground bar in the panel should already be securely bonded to the metal panel itself. -Sean http://OurOdyssey.BlogSpot.com | ||
| Pete/RTS Daytona (Pete_rtsdaytona)
Registered Member Username: Pete_rtsdaytona Post Number: 540 Registered: 1-2005 Posted From: 97.104.21.0 Rating: N/A |
I'm confused My breaker box is PLASTIC Am I required to ground the BREAKER BOX - GROUND BAR TO THE BUS FRAME ?? Pete | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 794 Registered: 1-2003 Posted From: 72.171.0.140 Rating: N/A |
Yes, with a #8 wire. Sorry, did not realize you had a plastic box. I probably should say more about this, but gotta run for now, taking Louise to the airport. -Sean http://OurOdyssey.BlogSpot.com | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 795 Registered: 1-2003 Posted From: 72.171.0.142 Rating: N/A |
OK, took me a minute to look it up after I got back from the airport: Only type "NM" (commonly referred to by the trade name Romex®) cable or non-metallic raceways ("NMC," for example, "smurf tube") are permitted to be used with non-metallic boxes. If you have the more common metal-enclosed panelboard, this restriction only limits you to NM or NMC on branch circuits that terminate in or pass through non-metallic junction boxes. You could still use, for example, metal-clad ("MC") cable or other metallic types, or metal conduit, to go to metal fixture boxes, or hard-wired appliances (e.g. air conditioners) with integral metallic junction boxes. Since your panelboard itself is non-metallic, you are limited to NM or NMC for every branch circuit originating in that panel. The panelboard should have two isolated busses, one for neutral and one for ground. The ground bus should be connected directly to the vehicle frame with #8 wire, either bare or with green or green w/ yellow stripe insulation. The neutral buss should remain isolated. If you terminate any circuits in metal boxes, you should ground the box itself; use a wire nut to splice a short length of ground wire from the box itself, the ground wire from the main panel, and a short length of ground wire from the device (receptacle, appliance, whatever). Hope this helps. -Sean http://OurOdyssey.BlogSpot.com | ||
| Len Silva (Lsilva)
Registered Member Username: Lsilva Post Number: 210 Registered: 12-2000 Posted From: 24.164.20.23 Rating: N/A |
The only thing I can add is that quite often you have to purchase the second isolated bus as an accessory item. Most panels only come equipped with one bus. I've never bought a plastic panel so I'm not completely sure that applies here. (Message edited by lsilva on March 16, 2009) | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 796 Registered: 1-2003 Posted From: 72.171.0.142 Rating: N/A |
Good point, Len. Many listed panels sold for use as main distribution panels do not have insulated neutral busses. All such panels, though, have one available as an option, since this is required for use as a sub-panel in fixed installations. -Sean http://OurOdyssey.BlogSpot.com | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 985 Registered: 12-2000 Posted From: 71.54.29.215  Rating: N/A |
The GE metal boxes I used for both main and sub panels had 1 neutral strip that was electrically connected to the case by 1 screw. Removing that screw broke the connection to the case. I had to add an additional neutral strip (connected to the case) for the ground (green) wires. Jack | ||
| niles steckbauer (Niles500)
Registered Member Username: Niles500 Post Number: 909 Registered: 11-2004 Posted From: 173.78.29.189 Rating: N/A |
Gonna throw two cents in here - Not for those who posted above - but for any others who might be reading this - "Aluminum is prohibited for the bonding wire if it attaches in a place exposed to the elements, where corrosion can occur" Even though Sean was stating the code, and it is allowed, I would caution against using Aluminum wire anywhere on your coach INCLUDING the main lugs - It's a failure waiting to happen - FWIW | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 797 Registered: 1-2003 Posted From: 67.142.130.34 Rating: N/A |
I agree, Niles. But I felt I had to list the specific prohibition. -Sean http://OurOdyssey.BlogSpot.com | ||
| Randy Davidson (Rdavidson)
Registered Member Username: Rdavidson Post Number: 18 Registered: 7-2006 Posted From: 166.214.103.48 Rating: N/A |
FWIW - My AC plastic panel box has two bars, one for neutral, one for ground, that are NOT bonded together. I believe it is made by IOTA. You need not purchase a separate bar for this type box. | ||
| niles steckbauer (Niles500)
Registered Member Username: Niles500 Post Number: 910 Registered: 11-2004 Posted From: 173.78.29.189 Rating: N/A |
Oh Sean, I know you know, along with all who posted above my comment - Just had a feeling that some soul (newbie) reading this might think it's an accepted practice to use AL - I guess it was just my turn to play Mother Goose - | ||
| Kasse Weikel (More_s_than_as)
Registered Member Username: More_s_than_as Post Number: 6 Registered: 4-2009 Posted From: 71.84.122.200 Rating: |
heres where my "i know a little about a lot" disposition might help anyone looking this up later in hte archives. i dont know much about what they all are talking about here, but i do know about grounding panels and appliances. most boxes now (i just bought a main and sub) only have 1 ground bar, but it will be longer than a traditional one with 2 ground bars (you see this style a lot in older houses). the whole idea about the neutral is its a safety overload for 120(110) applications. with 240(220) theres only one ground straight up because your running half the amperage with 240. The point being...its perfectly ok to to put your neutral (green wire) and your ground (bare/brass wire) to the same ground bar, and this is now actually commoc practice, however 2 bar panels can still be purchased if you want to. i would also recommend that if you have a metal box tacked to the sheet metal or small tube ribbing of the bus wall, and your running heavy currents, run your ground bar down through the floor to the biggest hunk of metal on your frame (if you can do so and make it look good). although the sheetmetal will ground out just fine, im always crazy cautious about electrical stuff (paranoia i guess). | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 1009 Registered: 12-2000 Posted From: 71.3.75.244 Rating: |
"The point being...its perfectly ok to to put your neutral (green wire) and your ground (bare/brass wire) to the same ground bar, and this is now actually commoc practice" In residential wiring yes, But not in RVs. Check the RV section of the Electrical Code. Jack | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 817 Registered: 1-2003 Posted From: 67.142.130.38  Rating: |
I beg to differ. This kind of advice can get someone killed. Please, please, please -- if you don't know what you are talking about, don't dispense advice as if you do. What you proposed is against code, illegal, and, more importantly, can energize the frame of the coach, giving anyone standing on the ground a possibly fatal shock. DON'T DO IT. I can recommend you educate yourself on this matter by purchasing a copy of the code for $75 on-line from the NFPA, or you can find it in most libraries. Also, there is a lot of information on this exact issue right here in the archives. You seem to have revived a month-old thread just to contradict, incorrectly, the advice therein. -Sean http://OurOdyssey.BlogSpot.com (Message edited by Sean on April 14, 2009) | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 611 Registered: 7-2006 Posted From: 75.211.173.180 Rating: N/A |
Sean....great advice and, as usual. you are dead on... ...but, dear Sean...be kinder...gentler...more humane....more loving....we are all in this world together. Some with moxy(ie)...others,... well..you know what I mean.  Semper Fi! And I wasn't a Marine RCB | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 818 Registered: 1-2003 Posted From: 67.142.130.38 Rating: |
I'm sorry, Chuck, but this sort of statement, IMO, requires firm handling. If that came across as less than "kind," it's because I take this sort of life safety issue very seriously. If those remarks had been prefaced by any sort of tentativeness whatsoever, such as "I think" or "what I remember" then my response might have been less forceful. But the statements were presented as "fact" with no qualification whatsoever. I would guess that the majority of folks here know better. But the chance that even one person could come along and follow this advice is unacceptable. The whole post was, in fact, riddled with errors:
But I digress. The chief problem with the post was the blanket statement that it was "perfectly ok to ... put ... neutral ... and ... ground [on] the same ground bar," (it's not -- it is dangerous and unlawful to do so) and "this is now actually commoc [sic] practice" (also not, except in the limited circumstance of a main building panel, where it is allowed if it is the main point of entry of the service, and the point of connection to the earth ground). So, sorry if I sounded harsh, but I believe it was an appropriate and measured response. (Nevertheless, I have changed some wording that might be construed as unnecessarily inflammatory.) I bear no ill will toward Mr. Weikel, and will be more than willing to assist him in learning more about this subject, but I implore him to be more circumspect in what and how he posts here -- there is a wide readership on this forum. -Sean http://OurOdyssey.BlogSpot.com (Message edited by Sean on April 14, 2009) | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 613 Registered: 7-2006 Posted From: 75.210.21.18 Rating: N/A |
As I said, Sean...dead on.... but diplomatically; We luv ya', Sean! (and listen to Ian.. ) RCB | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 797 Registered: 8-2006 Posted From: 64.55.111.6 Rating: N/A |
Chuck, Does it matter if somebody is diplomatically dead, or harshly dead? In this matter, you have to get somebody's attention, and you have to get it now! When somebody posts that his bus won't start, and gets a reply that his transmission may be stuck in two gears, the only harm that will do is a couple of minutes lost time until he figures out that depressing the clutch disconnects the engine from the trans! Kasse's post WAS UNINFORMED AND DANGEROUS, PERIOD. You know that I never mention names, or call people names, or derogatory body parts, but this post requires an exception. How do people who are posting questions know which answers are right, and which are deadly???? Here we have Catch 22, only its not mental illness. (If you don't know you're not qualified, you don't know not to post?) Sean is WELL qualified to post on electrical issues, and once again, because a "newbie" is involved, I am a licensed electrical contractor. I am not going to mention any more names, as we pretty well know who all are qualified. We just lost one of the best in Richard Bowyer, but I'll guarantee the above post has him spinning in his grave! I'm sorry I'm using you to jump on someone else, but if we keep one more person alive, its worth it!! It must be understood that by splicing the neutral and the ground together in a bus, that the entire frame of the bus CAN become energized. The entire purpose of the ground wire in an AC circuit, IS TO CARRY FAULT CURRENT AWAY FROM PEOPLE, BACK TO THE POWER SOURCE! Electric panels with only one ground/neutral bar have meter sockets, and go on the outside of buildings, where the incoming neutral is grounded. Its very discouraging to have this particular subject discussed as much as it has been over the years, and then have a post like this show up.... I'm done, (and the only reason you aren't on me, is because Sean said it first!) Sorry, George | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 618 Registered: 7-2006 Posted From: 75.211.2.73 Rating: N/A |
Well, Jump on George....I certainly was not criticizing Sean in WHAT he said. And he, if no one else knows that, I think.  ....indeed, I stated he was absolutely correct. Not sure why you are taking offense at the suggestion of a "softer, more gentle approach" to presentation...diplomacy. Also what am I not understanding about.. "Its very discouraging to have this particular subject discussed as much as it has been over the years, and then have a post like this show up...."? what could I have possibly said that would be referenced as "a post like this"? "Experts", in any field, yours or the next guy's, earn their credibility and respect thru experience, and time....not thru "holier than thou" approach. Expert advice does not need to be pounded into folks. And Sean knows and acknowledges that. I cannot think of much of anything in the physical conversion of a coach that is not potentially dangerous, (unless it might be drawing the first cubes from a newly installed ice maker or, perhaps standing back and admiring one's work);... reference the new thread today "WARNING.".Electric wiring is not exclusively dangerous. Wonder if someone is just looking to vent. Meantime, for all who are offended by my remarks, I apologize. The sun will come up tomorrow... RCB | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 798 Registered: 8-2006 Posted From: 64.55.111.6 Rating: N/A |
Its morning, and I've got the handbook out. Section 250 of the National Electric Code, Article 250.24(A)(5) reads: "Load-Side Grounding Connections. A grounding connection shall not be made to any grounded circuit conductor on the load side of the service disconnecting means except as otherwise permitted in this article." Since this is the handbook edition, it explains the article this way: "Section 250.24(A)(5) prohibits regrounding of the grounded conductor on the load side of the service disconnecting means. This requirement is also in concert with 250.142(B)." Section 551 applies specifically to recreational vehicles, and 551.76(C) reads: "Neutral Conductor Not to Be Used as an Equipment Ground. The neutral conductor shall not be used as an equipment ground for recreational vehicles or equipment within the recreational vehicle park." Article 551.76(D) says the same thing as 250.24(A)(5). The circuit breaker panel in a bus is NOT the power source. The generator, the inverter, or the shore power are the power source, and the one place at a time, AND THE ONLY PLACE, where the ground and neutral are bonded (connected). Three more RV specific code sections, and I'm done: Section 551.54 Grounding "(A) Power-Supply Grounding. The grounding conductor in the supply cord or feeder shall be connected to the grounding bus (bar) or other approved grounding means in the distribution panelboard. (B) Distribution Panelboard. The distribution panelboard shall have a grounding bus with sufficient terminals for all grounding conductors... (C) Insulated Neutral. The grounded circuit conductor (neutral) shall be insulated from the equipment grounding conductors and from equipment enclosures and other grounded parts... Bonding screws, straps...shall be removed and discarded. The grounded (neutral) circuit terminals in the distribution panelboard and in RANGES, CLOTHES DRYERS,...WALL MOUNTED OVENS, shall be insulated from the equipment enclosure... Enough, George | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 799 Registered: 8-2006 Posted From: 64.55.111.6 Rating: N/A |
Chuck, I'M SORRY, I WAS NOT REFERRING TO YOU!!! You haven't made a dangerous post here yet! I'm all for diplomacy, and as I was gone for 3 days, which happens once a week, apparently I didn't see Sean's first post before he edited it. My second post took an hour to finish, as the phone won't stop, so it appeared after yours. This is an attempt at PERSPECTIVE, the poster who started this has been beaten up enough, but lets look at several of the last posts, ok? One asks if his engine is DDEC or mechanical. One asks for mechanic references, etc. Another says "I just bought this Phantom..." Then comes the "one bus bar panel post"! Correct me if I'm wrong, but he has owned his bus for a whole week now, right? The four of us involved in this all put a pair of pants on one leg at a time, and three of us know not to post where we're not qualified. How do we know who is qualified? More importantly, how does a newbie know? The sun will indeed come up tomorrow, AND if we don't mis-wire our buses, us and ours will be around to watch it! George | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 620 Registered: 7-2006 Posted From: 75.211.2.73 Rating: N/A |
Happy Days are here...again!!!!!.... ....wheewwww. Thanx for the reflection, George.I hate being crosswise with anybuddy...reminds me of my first wife. ....(my fault..not hers) RCB | ||
| Cullen Newsom (Cullennewsom)
Registered Member Username: Cullennewsom Post Number: 78 Registered: 2-2009 Posted From: 203.176.193.103 Rating: N/A |
What we've got here... Is failure... to communicate. Seriously, we need a little cartoon drawing or schematic or something to clearly illustrate why RV's (and boats) are different. |
