Solar

[wyliesdiesels]

Shouldn't the ground switching be handled by the transfer switch?

I have never seen a transfer switch switch the GECs. did you mean neutral? only some transfer switch switch the neutral. usually they dont.

 

[wyliesdiesels]

There's no transfer switch on an RV....

The problem w/ tying the neutral and ground together in an RV is that when you plug the RV into a GFCI, both the neutral and the ground share the current... but the GFCI sees less current on the neutral than it sees on the hot line, and immediately trips.

you are not supposed to bond the neutral anywhere except the main service panel regardless of whether there is a GFCI.

 

[dcg9381]

I have never seen a transfer switch switch the GECs. did you mean neutral? only some transfer switch switch the neutral. usually they dont.

Yes, I meant neutral. I think the transfer switches setup for generator power usually did that switch for you. Obviously you don't want to bond the RV if connecting to shore power.

The ******** "inverter" space in RV-land seems to be bleeding edge and problems with GFCI because of how they're doing these things seem to be common.

 

[reader2580]

We've gotten way off the original topic, but I will explain how my motorhome is set up for ground/neutral bonding.

I have a diesel generator, shore power, and an inverter. The generator has the neutral and ground bonded inside of the generator. The generator is isolated from shore power by an automatic transfer switch when the generator is not running. The inverter has a ground bond relay in it that is open when shore power or generator power is available, and is closed when the inverter is creating AC power.

 

[wyliesdiesels]

Yes, I meant neutral. I think the transfer switches setup for generator power usually did that switch for you. Obviously you don't want to bond the RV if connecting to shore power.

The ******** "inverter" space in RV-land seems to be bleeding edge and problems with GFCI because of how they're doing these things seem to be common.

not true. ive seen many transfer switches that do not switch the neutral. its totally optional....

 

[wyliesdiesels]

We've gotten way off the original topic, but I will explain how my motorhome is set up for ground/neutral bonding.

I have a diesel generator, shore power, and an inverter. The generator has the neutral and ground bonded inside of the generator. The generator is isolated from shore power by an automatic transfer switch when the generator is not running. The inverter has a ground bond relay in it that is open when shore power or generator power is available, and is closed when the inverter is creating AC power.

and where is the transfer switch located? just after the meter or after the first means of disconnect on the service?

 

[reader2580]

and where is the transfer switch located? just after the meter or after the first means of disconnect on the service?

It is an RV so you don’t really have either of those. My transfer switch is located before the main load center. It is an RV specific transfer switch that transfers both hot and neutral.

 

[ching0n]

Anyone's that done this try their luck w/decommissioned panels that are cents to the dollar on ebay? AFAIK they test good but are pulled from farms due to life cycle/efficiency/other reasons.

 

[ching0n]

I also think I am also in a demographic that is apt to make this sort of mistake - I have degrees in EE and physics and have a tendency to suffer from what we call 'physicist syndrome', which is the idea that you can figure anything out from first principles, and don't really need practical experience or training.

Generally I can figure out how things are supposed to work, but don't have the practical experience to know and plan for all the ways that it could, and at some point will, go wrong. Which is where the electrical codes and inspectors come into play, they are based on decades of experience of things going wrong, and take the wild card of human nature into account - I don't always know why the code is the way it is, but it is usually for a good reason that I haven't thought of.

There's the Darwin tax a lot of STEM people minimize when going the DIY way. That is, people having paid w/their lives/injury by chance or error spurring countermeasure revisions...which may not make sense to STEM types until explained. I read a quote on tradition and while I don't 100% agree with it rings true none the less and applies here IMO:

"Tradition is a set of solutions for which we have forgotten the problems. Throw away the solution and you get the problem back."

 

[wyliesdiesels]

It is an RV so you don’t really have either of those. My transfer switch is located before the main load center. It is an RV specific transfer switch that transfers both hot and neutral.

If it is before the main service panel, then it is the main service panel.

 

[ipgenie]

Anyone's that done this try their luck w/decommissioned panels that are cents to the dollar on ebay? AFAIK they test good but are pulled from farms due to life cycle/efficiency/other reasons.

My panels are used from a solar farm. They were 3 or 4 years old. I bought 100 of them from Santan Solar through their ebay listing and all were in excellent shape. Mine were $0.40 on the dollar compared to new and I got 4 spares because I bought out of warranty. I'm going to put the spares to work somewhere, it's been 5 years and I don't need to just leave them sitting around. I still have times of the year where the panels produce above their rating. The manufacturer has a degradation chart that rates them out to 40 yrs old.

I've since purchased from the same seller through their website for a couple of other smaller projects, each time with good results.
They sometimes offer white label panels that can't be used for grid tie systems, but are sold at excellent prices and great for RV or off grid use.

 

[reader2580]

Anyone's that done this try their luck w/decommissioned panels that are cents to the dollar on ebay? AFAIK they test good but are pulled from farms due to life cycle/efficiency/other reasons.

Not from EBay, but I purchased 22 used solar panels from Sun Electronics back in 2017 or 2018. They are still working just fine. I also bought four used panels locally in 2020 that are still working fine.

I have heard that a lot of times a big solar farm might be hit by hail and they replace every panel, even ones not damaged. The undamaged panels get sold.

 

[ToolsRCool]

Mine were new, Mitsubishi Electric, but have a 25 year warranty to make at least rated power. So, as long as the panel is from a quality manufacturer, I'd think used should really be just as well.

Neighbor bought his new as well at the same time, some off brand. They work, and still work years later, but they have purple staining running all down the glass and frames of all of them. Looks terrible. Mine look exactly the same as the day they were installed.

 

[GearHead7]

Nice man! Looks like a quality install and I own a solar company here in CT! We use a ton of QCell panels as they are made in the USA and the best bang for your buck but we also use enphase micro inverters on basically every install we do, so great choice going with them.

In CT, as long as a homeowner owns their home we can actually get solar installed on their house for nothing out of pocket, they just purchase their electricity from the power now being produced on site at a significantly reduced rate than what they are paying the utility (30-50% cheaper).

If anyone is in CT, NJ, NY, MA, and more, look us up! Solara Solar!

 

[davejo]

A pinch under $6k total outlay before receiving the US Federal tax incentive back at the beginning of the following year. I think that incentive was nearly 40% at the time, somewhere in the 36%-40% range. Way less than the $25k solar companies were quoting, and I was able to use higher quality components.

$720 per kW capacity. That's exactly how much igenie's came out to, also.

The more i learn, the more persuaded i become. looks like i have net metering at my location. My pro-installed quote comes out to about $2200/kW

 

[ToolsRCool]

You should totally do it, especially if you have any South facing roof surface. It can be done for even less now since you can get used panels for cheap.

 

[handyman_1]

Just a brief post about rooftop solar, for anybody considering it. I did it myself, and love the result. There are really only 3 parts and 2 wires. If you have an un-obstructed South facing roof surface, there is a lot to be gained. West works too. In my case, it is like having a 5.8kW generator running anytime the sun is out. Has been 100% maintenance free since installation. Was a full city permit build and inspection per utility company requirements. There are solar farms now popping up, which will be a different config than here.

I did 21 Mitsubishi 280W panels, and used micro-inverters, one per, so the system pushes in parallel vs series (no bottle-necks). Internet connectivity is not required, only for monitoring of system performance. 2.5 year ROI, electric bills are only $9 a month now (line connection fee) no matter how much we run the A/C. Even though we're in MI, it covers about 10 of the 12 months of total usage. No battery because we are still grid tied. Utility comes out and re-flashes the digital smart meter to basically have 2 odometers, one in each direction, of which they are totaled each month. At least in MI, the utility never really pays you for excess generation, but instead credits are issued of which you use at night and in the winter months. Meter reads negative during any daylight hours.

Nothing to sell, just an advocate for rooftop solar if anybody has any DIY questions, I'd be happy to answer. Utility rates are only ever going to increase. In this instance, it felt great to cut ties with the man. Solar incentives and rules differ per state, so I really only know them for MI. Even those have changed a bit since I did this a few years ago. There is, or at least was, also a US Federal tax rebate pertaining to such. Used panels are even available now in the market for very low cost, which really drives the total cost even lower.

Siding is shot in the below pic. Garage getting a full tear down and rebuild this spring.

 

[handyman_1]

Just a brief post about rooftop solar, for anybody considering it. I did it myself, and love the result. There are really only 3 parts and 2 wires. If you have an un-obstructed South facing roof surface, there is a lot to be gained. West works too. In my case, it is like having a 5.8kW generator running anytime the sun is out. Has been 100% maintenance free since installation. Was a full city permit build and inspection per utility company requirements. There are solar farms now popping up, which will be a different config than here.

I did 21 Mitsubishi 280W panels, and used micro-inverters, one per, so the system pushes in parallel vs series (no bottle-necks). Internet connectivity is not required, only for monitoring of system performance. 2.5 year ROI, electric bills are only $9 a month now (line connection fee) no matter how much we run the A/C. Even though we're in MI, it covers about 10 of the 12 months of total usage. No battery because we are still grid tied. Utility comes out and re-flashes the digital smart meter to basically have 2 odometers, one in each direction, of which they are totaled each month. At least in MI, the utility never really pays you for excess generation, but instead credits are issued of which you use at night and in the winter months. Meter reads negative during any daylight hours.

Nothing to sell, just an advocate for rooftop solar if anybody has any DIY questions, I'd be happy to answer. Utility rates are only ever going to increase. In this instance, it felt great to cut ties with the man. Solar incentives and rules differ per state, so I really only know them for MI. Even those have changed a bit since I did this a few years ago. There is, or at least was, also a US Federal tax rebate pertaining to such. Used panels are even available now in the market for very low cost, which really drives the total cost even lower.

Siding is shot in the below pic. Garage getting a full tear down and rebuild this spring.

That's amazing!
I'm setting up my own solar panel for water heater. I'm using a differential thermostat (model DIN-S from ThermoMart) that solved my pump problem. I though it's good to share it here as it may come in handy for other too.
Here's the link:

Differential Temperature Controller – $43.99 | Dual Sensors for Solar Water Heater, Pool, Greenhouse, Boiler

Advanced Differential Temperature Controller, dual waterproof sensors, heating and cooling modes, alarm alerts, ideal for solar water heater, Boiler, pools, greenhouses and HVAC systems $43.99!

www.thermomart.com

Hope it helps!

 

[davejo]

You should totally do it, especially if you have any South facing roof surface. It can be done for even less now since you can get used panels for cheap.

I'm knee deep in learning about this stuff now. rabbit hole

I'm guessing you have an older generation of enphase microinverters? You mention a monitor module connected to the internet?

The current stuff requires additional proprietary components in addition to the microinverters. Then you have to get certified online as an installer for the inverters to be "commissioned" or turned on remotely by the company.

I'm going to put mine on a shop without internet available so my diy is *********** on me

 

[ToolsRCool]

Fun stuff, I had to dive and dig deep as well, but it was exciting to do so.

Yes, my Enphase stuff is about 6 or 7 years old now. I even forgot their model numbers. But correct, they did not require any internet connectivity or additional (communication) modules to work. The additional wi-fi communication module was just for monitoring of them, their health and output, if desired. I bought and used it, but it was not required.

I have not kept up with their changes. Maybe the self-certification is easy (free-online)? Maybe you can just buy some older used micro-inverters if you want to avoid such?

 

[dcg9381]

That's amazing!
I'm setting up my own solar panel for water heater. I'm using a differential thermostat (model DIN-S from ThermoMart) that solved my pump problem.

I'd love to see the design. I've done two "thermosyphon" systems, which worked absolutely great, but you don't often see them in the USA.