| Author | Message | ||
| Christopher Goodwin (Cgoodwin)
Registered Member Username: Cgoodwin Post Number: 77 Registered: 10-2005 Posted From: 71.212.69.130 Rating: N/A |
I have been reading until my eyes burn about wiring up a SW4024, I read through Seans disertation on wiring systems and code, read Grumpy Dogs page and a few others and read the posts here on the subject and have yet to find a direct and simple explanation of the issue with neutral/ground bonding and breaking it when attached to shore power with simple illustrations. I have decided to put such an article together (Unless someone can point me to one already out there) and would appreciate any help or suggestions. 1) When installed the AC system in the bus needs to have the neutral and ground bonded. 2) When connected to shore power the on-board neutral to Ground bond must be broken and connected to the neutral and ground in the shore power cord. 3) This making and breaking of the bond must be automatic and can not rely on manual action (plug swapping, switch throwing, etc) making a relay wich closes the bond in its resting position and is powered by shore power to energize and break the bond the best choice. ?) would it not be prudent to check the shore power with a tester before plugging in and relying on the wiring in the supply for your safety? I have seen some pretty dodgy wiring at camp spots.... ?) Best source for relays capable of the amperage we are talking about (50amps, 120vac). ?) Does anyone make a prewired fuse panel for this application? Something like Painless Performance does for the racing community (http://www.painlessperformance.com/)?? | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 179 Registered: 7-2006 Posted From: 4.240.213.247 Rating: N/A |
Christopher...I have pondered the same thing. I purchased an automatic transfer switch (Ron the Bus Nut) and followed carefully the instructions, including several clear diagrams, furnished by the manufacturer...in this case Trace. (Xantrex) So far no problems, after several years.... But nevertheless I think, occasionally, about how the system works. I did discover just yesterday that I had grounded the house batteries to the chassis, so disconnected the ground and let the ground from batteries to the inverter take care of it. (the inverter is chassis grounded). FWIW  RCB | ||
| Ron Walker (Prevost82)
Registered Member Username: Prevost82 Post Number: 322 Registered: 11-2003 Posted From: 208.181.210.47 Rating: N/A |
When on Shore Power neutral is not grounded (like sub panel) When on Generator or Inverter running off batteries neutral is grounded (like main panel) Ron | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 597 Registered: 1-2003 Posted From: 67.142.130.17 Rating: N/A |
Chris, The neutral-ground bonding, by itself, is indeed very simple. In fact, there is a good diagram of it in your SW4024 manual. (Figures 12-14 on pp. 27-28) What most installers do, and this makes everything quite simple, is to use an external transfer switch for shore vs. generator, and connect the output of the transfer switch to the AC2 input of the SW4024. The AC1 input is left unused. So you need a 50-amp three-wire (two hots and one neutral) transfer switch, and one relay for the ground bond, and you're done. The long, complex description and diagrams on my web site have to do with the fact that I was unwilling to do it this way -- I wanted to use AC1 for shore power and AC2 for generator. That necessitates a much more complicated switching arrangement, due to the fact that the internal transfer switch in the SW4024 is single-pole (it switches only one hot, and gangs the neutrals). I can appreciate you wanting to "simplify" it, but I can assure you that it is not simple. Many people have roundly criticized Trace for these design deficiencies (lack of ground/neutral bonding and lack of neutral switching on the transfer switch), but one should remember that this inverter was not originally designed for mobile applications. It was designed for alternative energy, grid-tie use, where the connection to the grid (and thus to a bonded ground) is permanent. The MC software was added later, as an afterthought. BTW, relays are readily available at Grainger, Allied, and Newark. Transfer switches can be had at Ron the Busnut, Northwest RV surplus, and many other discounters, as well as from anyone who sells generators (such as Dick Wright). FWIW. -Sean http://OurOdyssey.BlogSpot.com | ||
| Christopher Goodwin (Cgoodwin)
Registered Member Username: Cgoodwin Post Number: 78 Registered: 10-2005 Posted From: 67.40.193.222 Rating: N/A |
Sean, I completely understand and appreciate the complexity of your system, however, not everyone needs 240VAC and unless I am mistaken, this caused a great deal of the complexity in your system. My background is as a Mercedes, Porsche tech, race mechanic, I designed diving equipemnt for the film industry for many years and built expedition vehicles for Discovery and Nat Geo and relied on the systems in the vehicles and the diving gear for my very life. While I do not want to cheat or skimp on the design of the system, I and others simply do not need a system so complex. I applaud your thourogh descriptions and diagrams and if I needed such a system I know I could copy yours with the information provided with complete confidence. On my bus I simply need a genset, battery bank, shore power cord, alt connection, inverter/charger and a couple of 110vac outputs for a few outlets and the AC units. And from what I have seen, a detailed diargam for a system like this does not exist. Xantrex has some information on the use of the SW4024 in marine applications but they seem frightened (likely due to liability) to provide basic diagrams for the neutral/ground bond disconnection, etc. Would you be willign to help me with such a project? I have plenty of space to host diagrams, images, parts source lists, etc. | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 598 Registered: 1-2003 Posted From: 67.142.130.17 Rating: N/A |
"not everyone needs 240VAC and unless I am mistaken, this caused a great deal of the complexity in your system" Not really -- the complexity of the transfer switch and generator start systems really had to do with the lack of neutral switching in the SW-series inverters. FWIW, we don't use any 240 aboard Odyssey. But we have a 70-amp/240-volt generator and a 50-amp/240-volt shore cord (as do many large rigs), and so that extra hot leg had to be dealt with somehow. Some additional complexity in my design comes from having a set of loads (e.g. electric water heater) that we wanted to run off leg 2 when it was available, but through the inverter when only leg 1 was available (and not at all when neither leg was available). One can greatly simplify the design of a coach electrical system by avoiding this "second leg" of incoming power. However, that really limits how much power you can utilize from the shore connection. Remember that a "50-amp" shore service is really 12 kilowatts. If you choose to design for one-leg shore input only, then the most you will ever be able to use is 6 kilowatts, and that assumes you will be plugging in to "half" of a normal 50-amp shore service. A 30-amp shore service is even more limited, with only 3,600 watts available. Our coach has been designed for maximum efficiency. Without air conditioning, we could run the whole coach indefinitely on less than 10 amps (@ 120v = 1,200 watts) of shore power. But in normal use, we will need to charge batteries, and possibly run air conditioners from the shore input (darned if I'm going to pay for it and not use it!), and under those conditions, we could easily draw the entire 12Kw. Here's the math: 4 Air conditioners @ ~1,600 watts = 6,400 watts Battery charging @ max rate = 3,600 watts Water heater = 1,700 watts Fridge and misc. loads = 200 watts ---- Total: 11,900 watts. By contrast, on a 6kw shore service, you would be hard pressed to, say, air condition your whole coach on a hot day, and still have something left over for battery charging and other miscellaneous items. Of course, YMMV. For this reason, I generally recommend an 8KW generator for a 40' rig. And, sure, that can be 120-volt (which would require 70-amp mains and, if used, transfer switches). But you would still be limited to the 6Kw when on shore service. FWIW. I'd be happy to help you with documentation, but you need to keep in mind that there are almost as many ways to wire things as there are buses out there. Also, the SW-series inverters represent only a small fraction of the market for the self-converter, and that share is dwindling rapidly as smaller, cheaper units with better internal switching take over the market (most modern RV inverters now handle ground-neutral bonding internally, and those with both shore and generator inputs properly switch the neutrals). -Sean http://OurOdyssey.BlogSpot.com | ||
| Len Silva (Lsilva)
Registered Member Username: Lsilva Post Number: 129 Registered: 12-2000 Posted From: 151.213.167.7 Rating: N/A |
Just a quick note here; there is no reason you can't have 220/50A shore power and 120/70A generator as long as it's all properly protected. That makes it easier to keep the generator reasonably balanced. Of course, 220 volt equipment won't run off the generator but it won't do any harm either. In reality, I don't know that it actually does any harm to run the generator greatly unbalanced, I've just always heard that it's not recommended. Len (Message edited by lsilva on July 20, 2007) | ||
| Chuck Newman (Chuck_newman)
Registered Member Username: Chuck_newman Post Number: 207 Registered: 1-2005 Posted From: 63.145.177.245 Rating: N/A |
Chris, I can email you two diagrams a Xantrex engineer sent me that they recommend for the neutral-to-ground auto switching bonding issue, if you like. Interestingly, they don't publish it.I don't have the manuals at hand, but I believe they are different than the figures Sean mentioned. It's been some time. I may be wrong on that. But he is correct about the diversity of systems, not only bus conversions but in commercial RV's. | ||
| Chuck Newman (Chuck_newman)
Registered Member Username: Chuck_newman Post Number: 208 Registered: 1-2005 Posted From: 63.145.177.245 Rating: N/A |
Chris, Forgot to mention: 1. A good transfer switch is made by Iota. Dick Wright has them at reasonable cost. You can find many others. Search the web. I would not recommend one with numerous single pole relays. I have seen mechanical delay on one or more relays cause problems with protection equipment. 2. Yes it is very prudent to check an outlet before you plug into it. Anywhere! I have seen one occasion and read about another where the neutral was not connected and the hot and ground reversed. A hot ground puts 120vac on the frame of your bus. The breaker feeding the outlet box saw no problem because the outlet box was mounted on a wood post and not tied to earth ground. Not common, but it does happen. | ||
| Christopher Goodwin (Cgoodwin)
Registered Member Username: Cgoodwin Post Number: 79 Registered: 10-2005 Posted From: 67.40.193.222 Rating: N/A |
Chuck - Please do send the diagrams and where do I find Dick Wright? Sean - Either your diagrams are difficult for me to understand or the system is quite complex. I do not have washers or dryers and I do not Have a 240vac cooktop. I do have two 110vac under counter refers and 2 15kw AC units. I just find it difficult to comprehend that I will need a system as complex as yours. Is this what everyone is doing on conversions?? | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 599 Registered: 1-2003 Posted From: 67.142.130.38 Rating: N/A |
Chris, Yes, my system is complex -- sorry, I did not mean to imply that it was not. That's because I wanted to use every last feature of my SW4024, and I also wanted automatic energy management. I was able to do all this with relays I had lying around, and a few contactors I bought on eBay. I'm not suggesting anyone else make a system as complex as mine, but the diagrams are there for the taking in case someone does. I think your AC's must be 15KBTU/h, not 15Kw as you wrote. The 15K units will draw around 1,800 watts while running (considerably more to start up). That's a running load of 3,600 watts -- which would max out a 30-amp shore service. The point I was making earlier about extra complexity when a second leg of power is involved, whether that's just on the shore service, or also on the generator, is that you will either have things that just won't work at all when away from 240-volt power, or you will have to plan on a mechanism to moves those loads from "leg 2" over to "leg 1" -- there is no way around this. That mechanism can be automatic (like mine) using relays, or manual using a switch, or as simple as you move the plugs on those devices from one outlet to another. Dick Wright can be found at just about every bus rally and convention there is. His shop is Wrico International, in Eugene, OR. He used to have a web site, but that seems to be down at the moment. -Sean http://OurOdyssey.BlogSpot.com | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 180 Registered: 7-2006 Posted From: 4.240.141.33 Rating: N/A |
Christopher....no it is definitlely not what I have done....all good questions and thanx for pursuing the matter. Sean...my guess is that yours is a very unique situation and that most would not demand what you apparently do from a system...no criticism...just observation. RCB | ||
| Jerry Liebler (Jerry_liebler)
Registered Member Username: Jerry_liebler Post Number: 258 Registered: 3-2005 Posted From: 67.141.35.124 Rating: N/A |
Christopher, I have an SW2512, the 12 volt cousin of the SW4024 with all the same installation 'challenges'. I 'rolled my own' transfer switch and neutral bond control. Mine is even more involved than Sean's because I included a manual switch that disconnects the inverter and passes either shore or generator (like a normal automatic transfer switch with generator priority) around the inverter. The manual switch also can disconnect everything. For a neutral bonding control relay I used 2 DPDT relays with 20 amp contacts and wired all 4 contacts in parallel with equal length wires. The neutral bonding control relay's coils are 120 volts and also paralleled. I used contactors to switch neutral and hots from both shore and generator. Neutral is bonded to ground at the generator. The contactor coils are 120 volt and the contactors are normally open. The shore contactor supplys AC1 on the inverter and the generator contactor supplys AC2. The contactor coils are actuated by their respective sources but through a contact of a 4pdt control relay, a normally closed contact in the case of shore and a normally open in the case of generator. The 4pdt control relay's coil is powered by the generator. The other contacts 'commons' feed the neutral bonding relay's coil and the normally open sides go to generator neutral and hot and the normally closed sides go to shore cord's neutral and hot. The results are if neither shore or generator is present neutral is connected to ground and an open contactor isolates AC1 and AC2 from the inverter and the coresponding neutrals. If shore is present but not generator the neutral bond control relay is energised through the 4pdt relay and the shore contactor is energised (passing shore power to AC1 and neutral) also through contacts in the 4pdt relay, the 4pdt relay's coil is not energised. And if generator power is present the 4pdt relay's coil is energised preventing the passage of shore power to AC1, and selecting the generator as the power source for the neutral bond control relay and allowing generator power to the generator contactor's coil therby passing generator power to AC2 and neutral. Since I used 3 pole contactors the 'other hot' from shore is passed to the other side of my panel which has a single breaker for the electric water heater, the 3rd pole of the generator's contactor also powers the water heater but the generator is wired for 120 only. The Trace manual cautions against using an automatic transfer switch ahead of these inverters in the way Sean described, just using AC1. Using an ordinary transfer switch can destroy the inverter! The reasons for this caution are addressed by Sean's, and my, use of both AC1 and AC2. Email me off board for further details. Regards Jerry 4107 1120 | ||
| Jerry Liebler (Jerry_liebler)
Registered Member Username: Jerry_liebler Post Number: 259 Registered: 3-2005 Posted From: 67.141.35.124 Rating: N/A |
RC Bishop, I am of the opinion that you should reconnect your house battery's negative to the bus frame & not count on the inverter for this connection. A major reason is to allow charging house from coach electrical system which has the negative connected to chassis. Regards Jerry 4107 1120 | ||
| Christopher Goodwin (Cgoodwin)
Registered Member Username: Cgoodwin Post Number: 80 Registered: 10-2005 Posted From: 71.212.66.98 Rating: N/A |
Is it possible to post diagrams here? RCB - you wrote "no it is definitlely not what I have done", I am sorry, I do not understand to what you are refering... Look I am willing to post diagrams, install manuals, links, what have you. It seems to me that this is an area with little documentation, the inverters were designed for another use, marine application really does not apply and as people learn more the nomenclature becomes obsucre and difficult for the novice to understand. I simply do not think that this needs to be as difficult as it seems and what is needed is a clear explaination of even the complex system designs with diagrams. I can make the diagrams if need be. I spend many days writing and illustration amnuals which novices use to convert diesel engines to vegetable oil dual fuel systems, I am sure I can do this with a little help. Lets do a basic inverter wiring text so this subject is not beaten to death in 100 threads all lost to time, prevent someone from stepping from the bus to the earth and smoking thier.... bits and simplify what the manufacturers seem to have ignored. I have a $2000 inverter with remote, a 6.5 KW generator, about to get a $2500 battery bank, a couple of $1000 carbunkles and most impotantly a 12" stainless kitchen counter and the last thing i want is to replae any of these things or have my beautiful 4 year old daughter touch the counter to help daddy make a pasta sauce and turn to smoke! I may just end up copying Seans system, I am sure it is safe, to code and redundant, what bothers me is that I have need for only 5 110vac outlets and everything else will be 24vdc and the system seems complex beyond my needs or the needs of Joe average. If I am wrong tell me to pee up a rope and I will drop it. | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 181 Registered: 7-2006 Posted From: 4.240.213.152 Rating: N/A |
Jerry....thanx for the input. I know I did it for a reason when it was done, and really, no problems since then,,,,,however, I recently purchased two desulfators (Whizbang on Ebay)and attached one to the house batts (5 gp 27 deep cycle marine) and the other one to three gp 31 start batts. Before I hooked them up the inverter would charge consistently at about 12.6 or so, usually a bit more. The generator would charge at 13.8 or thereabouts. Also serviced the batteries, tightening, cleaning,etc. After the desulfator attachment, the batts (both sets) went down to 11.6 max, and stayed there, in spite of the 10 watt solar charger on each set (2 solars...in place for two + years). I could only think of where I might have gone wrong on the original setup. The inverter showed a flashing green at 11.6. I wasn't satisfied with that. As I reviewed the inverter manual, it was clear the instructions said DO NOT,,,,,so I undid . I put both sets on a charger (not the inverter charger)a couple of days ago....slow charge....and they are both now reading 12.5 plus. The delulfator guy says he sees no problem with what has transpired so far, but has not addressed the "reason" why the voltage went down. Therefore, my concern. Clear as mud, ehwhat? Thanx again for your remarks...(I'm still very much confused) defend defend defend, please. RCB | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 182 Registered: 7-2006 Posted From: 4.240.213.152 Rating: N/A |
Christopher...you said " Is this what everyone else is doing on conversions"....no I am not. I feel you have hit the nail on the head with your thoughts...Again, thanx for the thread. RCB | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 600 Registered: 1-2003 Posted From: 67.142.130.19 Rating: N/A |
" The Trace manual cautions against using an automatic transfer switch ahead of these inverters in the way Sean described,..." Thanks, Jerry, for pointing this out, as I did omit it. What Jerry is talking about has to do with waveform synchronization, a problem that is peculiar to grid-tie inverters. Specifically, Trace (Xantrex) requires that any transfer switch wired ahead of the inverter be of the break-before-make variety, and that the break must be at least 100 milliseconds before the make. This is spelled out at the bottom of page 20 of the manual, under "External Transfer Relays." Really high-quality transfer switches have a user-settable break-before-make timing for exactly this sort of application. AFAIK, BTW, the Iota ITS-50R transfer switch mentioned earlier on this thread, sold and favored by Dick Wright, does not incorporate this 1/10-second delay, yet Dick has been using these switches in SW4024 installations for years without apparent problems. FWIW. -Sean http://OurOdyssey.BlogSpot.com | ||
| Craig (Ceieio)
Registered Member Username: Ceieio Post Number: 294 Registered: 12-2004 Posted From: 206.212.230.165 Rating: N/A |
Dick Wright can be found at http://wricointernational.com/buscon.html (he can also be found next door to NW RV Surplus in Eugene) Best Regards, Craig - MC7 Oregon | ||
| Chuck Newman (Chuck_newman)
Registered Member Username: Chuck_newman Post Number: 209 Registered: 1-2005 Posted From: 69.106.180.107 Rating: N/A |
Chris, I'm sorry I've been out of town this weekend. I'll email you the diagrams tomorrow. I don't know how to post them to the board and there may be a copyright issue. Sean is right on the 100ms resync issue on the 4024. If you really want to learn the nuances of AC and DC power in a non-technical but thorough and proper manner get a copy of "Designing Electrical Layouts for Coach Conversions" by George Myers. $39.50 from Epic Conversion Support. Some of the best money you will spend on your conversion. Talk to Sue or George at: 888-420-5645 or 937-426-9850. | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 184 Registered: 7-2006 Posted From: 4.240.237.56 Rating: N/A |
Jerry.don't drop off on us....Please give me more info on your last post on this thread....good logic, but what do you think about what the "manual" said? Thanx, RCB | ||
| Jerome Dusenberry (Jerry32)
Registered Member Username: Jerry32 Post Number: 32 Registered: 1-2007 Posted From: 148.78.243.51 Rating: N/A |
I believe in KISS methad of doing things and my answer to this was to put an outlet at the power cord that has nuet and grnd bonding tied together then just plug the power cord into the outlet when not on a pole. just use line converters down to 20 amp size and have a short cord to connect Jerry | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 617 Registered: 1-2003 Posted From: 67.142.130.24 Rating: N/A |
Jerry, Your KISS method, unfortunately, is illegal, and dangerous. Code does not permit the required bond to be made by a manual connection means, such as an outlet as you've described. The bond must be made automatically any time inverter power is available and shore power is disconnected. The one time you "forget" to connect that jury-rigged outlet (or it wiggles out while you are driving) will be the time that a 5-year old touches a faulty appliance, and gets a lethal dose of current because there is no way for the breaker to trip without the ground being able to return current to the neutral. This is why the code does not allow important life-safety features such as grounding to be accomplished with a mechanism that requires human intervention. Relays to do this are less than $10. Why risk your life for this amount? -Sean http://OurOdyssey.BlogSpot.com | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1044 Registered: 12-2000 Posted From: 74.12.82.240 Rating: N/A |
Hello Did Jerry not describe a plug in manual system, where you shift the plug from shore power, to inverter or to generator? No automatic switching, no pass through, three different ways to get power, three recepticles, coach on the plug as the load. Is that wrong too? happy coaching! buswarrior | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 230 Registered: 8-2006 Posted From: 207.231.81.129 Rating: N/A |
Jerry, I must second Sean, and I also agree with KISStupid. Ground/neutral bonding in a nutshell=ground+neutral bonded at the power source, period. This means at the park panel when on shore, at the gen when running, OR at the inverter. The perfect example of a failure is for the neutral and ground to be bonded somewhere in the bus, and the neutral path goes open somewhere between the bus panel and the park panel, which can be a total distance of several hundred feet, with many splices. Now, all of the neutral current tries to travel in the ground wire, WHICH IS ONLY DESIGNED TO CARRY FAULT CURRENT! Voltage now appears between the bus frame and the dirt and nearby grounded objects! (Cable TV Coax IS grounded, and NOT capable of carrying much current, [read] hot quick!) No other obvious signs are present, until the ground fails, when everything quits. At that point, the entire bus, INCLUDING THE SIDING, is 120V to ground due to the ground/neutral bond in the bus. Since nothing is working, you ASSume it's all dead, which is deadly! (This means YOU complete the circuit when you open the door on damp grass!!!) There is also a good chance that a 50 amp park connection will have #6 wire on the hot legs, and a #12 run to a nearby water pipe for a ground, which just won't carry the neutral current. I don't want to jump on you, I just don't want you, your family, or any other of us bus nuts hurt. I am a licensed electrician, Sean is imminently well qualified, as is Jerry Liebler, of the people who have posted here, that I am familiar with. George | ||
| Jerome Dusenberry (Jerry32)
Registered Member Username: Jerry32 Post Number: 34 Registered: 1-2007 Posted From: 148.78.243.50 Rating: N/A |
With all the what if's you also could have a relay fgail too so I believe a mechcanical connection is better Jerry | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 623 Registered: 1-2003 Posted From: 67.142.130.31 Rating: N/A |
"Did Jerry not describe a plug in manual system, where you shift the plug from shore power, to inverter or to generator?" That's not the way I read the post -- if that is, indeed, what was done, then yes it is legal and safe. What I read was that he plugs the cord into an unpowered receptacle that merely has neutral and ground tied together. This is dangerous and illegal. Bear in mind that the sort of arrangement Buswarrior described, where the generator and inverter both have receptacles on them, and what is normally the shore cord is simply plugged in to one of these two alternate receptacles, will ONLY work with non-charging inverters (inverters that only provide AC power from DC, and don't have an internal battery charger). That's because inverter/chargers have only one set of AC wires for both Input and Output -- they supply AC power on these wires when inverting battery power to power AC loads, and they consume AC power on these wires when another source of AC power (e.g. Generator or Shore) is available, using this to charge the batteries. If you were to try to use the plug-and-receptacle switching mechnism just described for an inverter-charger, there would be no way to do the charging, as the cord would be connected to the shore supply, and nothing connected to the inverter. Make sense? Since most inverter/chargers therefore need to be connected in parallel across the AC wires that come from the shore cord, it is mandatory that ground and neutral be automatically connected when the inverter is running and shore is not connected, and automatically disconnected when the coach is connected to shore power. I hope this clears up what I wrote. And, Jerry, the argument that any component can fail does not fly with me, or with the law. Statistically, the single most common point of failure is the human factor. It is millions of times more likely that you will forget to make the connection than that a relay will fail in service. Millions. -Sean http://OurOdyssey.BlogSpot.com | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1045 Registered: 12-2000 Posted From: 70.53.130.135 Rating: N/A |
Thanks Sean, most helpful. happy coaching! buswarrior |