# sw4024 trace



## paperboy-7 (Feb 15, 2005)

hi all finally broke down and bought a used system.the sw4024 inverter snw09125, 12 bp pannels rated for 100amps total. looks like some of you have this inverter is it a good one? mines 8yrs old, have they upgraded much in 8 yrs? any advice always welcome. thanks nfp


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## WisJim (Jan 14, 2004)

My SW4024 is bout 8 or 9 years old, in use continuously, no problems except lightning damage to the AC input side due to a mistake in grounding--one too many ground connections when I installed it. I haven't kept up with any changes or improvements, since I have no problems. I do wish that they would use the temperature compensated battery voltage for all of the internal processes of the inverter, instead of actual voltage for some and temp compensated for others.


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## paperboy-7 (Feb 15, 2005)

hi what was your ground problem? the inverter shows error not checked out yet not home. thought it was because bats are dead. will have to read book. is the factory good about fixing or do you do your own? i used 4 pannels on my sail boat for 20yrs solar-x was all dc power had a 1500w inverter but never used on boat... i luv solar. thanks nfp


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## WisJim (Jan 14, 2004)

My ground problem was that I incorrectly had grounded the inverter chassis to a seperate rod than the ground that was connected to all other grounds in the system.


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## sisterpine (May 9, 2004)

I know it is impolite to ask but could you give us a rough estimate of the price you paid for your used inverter and panels. Thanks, sis


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## paperboy-7 (Feb 15, 2005)

hi they want 5000 but open because of inverter may need work, not sure on final cost, thats the ballpark. thats 1/2 of what they paid new. later nfp


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## idahodave (Jan 20, 2005)

I have a 5 year old 4024....no problems yet, but it only gets about 3-4 months use each year.


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## paperboy-7 (Feb 15, 2005)

hi it looks like the 4024 is a very common inverter i would really like the 4048 so i can really get off grid, need 3 ph power to run sawmill,woodworking mach. but will get started w/what i can afford. will be nice to have grid back-up.im starting to forget my kids tell me but im wounnnnndering myself???????? later nfp


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## paperboy-7 (Feb 15, 2005)

hi wisjim im not an elect man but why would that make a diff, if all the grounds were deep in the ground and good? later nfp


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## Tango (Aug 19, 2002)

My inverter is also a SW 4024.


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## Ed_Stanton (Dec 28, 2004)

I also have a SW 4024, about 7 years old? The one thing that I don't like about this "older" model, vs. it's replacement, is that the older model does not use an internal battery back up for all the display and control settings. So, whenever I want to disconnect the batteries from the system for maintenance, I lose all my input settings and then have to input them all again. Not a huge inconvenience, but enough that sometimes I'd rather have the newer 4024 model. Otherwise it's been an excellent peformer for me and the fellow that I bought it from before. I keep it inside in my basement whereas the previous owner had it outside in an unheated shed and it operated fine through several northern Canadian winters.


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## WisJim (Jan 14, 2004)

paperboy-7 said:


> hi wisjim im not an elect man but why would that make a diff, if all the grounds were deep in the ground and good? later nfp


If you have multiple grounds in a system, connected to different parts of the electrical components, you could get a current flow through the components, and if that current flow is lightning, it can cause damage.


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## Tango (Aug 19, 2002)

WisJim how many grounds are too many? I have one at the panels and one at the inverter. Also the electrician separated the ground from the neutral wires at the ac breaker.


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## Allan Mistler (Jun 1, 2004)

There should be but one ground system right there at the inverter. That ground should be carried forward to the house SUBPANEL unless you are completely off-grid in which case you'll carry that one ground to the main panel. At any point beyond the inverter, neutral and ground remain as separate wires since, as WisJim said, multiple ground wires can develop potential voltages along their lengths and result in damage to sensitive electronics at a minimum and potential shock hazards if the ground currents are great (as would be the case with a lightning strike). All solar system inverters are to be ground fault protected according to NEC 2005 and this would preclude having multiple grounds for sure! There are, of course, variations on the theme since there are so many ways to install solar. So here's a link to a good background on the electrical needs of a solar installation to meet the National Electric Code standards as of 2005...
http://shop.altenergystore.com/pdfs/photovoltaic_NEC_code_practices2005.pdf


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## idahodave (Jan 20, 2005)

"All solar system inverters are to be ground fault protected according to NEC 2005"

I can't find this requirement in the NEC....could you give me a section paragraph number? I only found a requirement for ungrounded systems.


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## Allan Mistler (Jun 1, 2004)

idahodave said:


> "All solar system inverters are to be ground fault protected according to NEC 2005"
> 
> I can't find this requirement in the NEC....could you give me a section paragraph number? I only found a requirement for ungrounded systems.


Dave, I apologize as that statement is, perhaps, an overstatement. I thought about that and appended on my post, the intricacies of compliance are varied... so, in accordance with NEC 690.5: "Roof mounted dc photovoltaic arrays located on dwellings SHALL be provided with dc ground fault protection to reduce fire hazards". Mind you it doesn't stop there since as you mentioned it is also required for both dc and output circuits in ungrounded systems in 690.35(C). Since a great number of solar systems are mounted outdoors with the inverter and control electronics being located in areas that would otherwise require GFCI, it becomes a reasonable issue. The requirements for grounding are comprehensive and quite involved, so it's best that an installer be familiar with the entire Article 690 of the Code as well as referenced articles.
I used to have to argue this code book with local inspectors and found it to be an interesting exercise in futility, so please merely accept the .pdf file attached above as a tutorial on how to wire in your SPECIFIC solar system and at least be able to defend your work with the county electrical inspector. :shrug:


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## Jim-mi (May 15, 2002)

Tango, Yes the the frame work used to mount the PV pannels should have a seperate ground-------not tied to either of the (+ or - ) going to the controller\inverter.

Another issue; Yes you can have multiple ground rods--BUT--- they are all to be bonded together. . . . .and tied into your system at only one point.

Some wind tower guy cable systems have 6 or 7 ground rods--all--bonded together. Thats a BIG bunch of copper in the ground.

The NEC code book has a hugh number of pages just on grounding. (I'm not gonna go get out the book to tell you how many)


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