diy solar

diy solar

Residential solar panel install part 2

What size wiring are you using to that inverter? A 1400W microwave will be pulling over 109A from the batteries, I hope you are using #2 or larger copper conductors… they appear small.
 
finish my install and test it out
Liking that transfer switch. Did I miss where you recounted the rating for it?

I noted that ‘position 2’ only has two wires. If I’m seeing that correctly the one concern is the bare/green/earth are not switched?

Shorepower should provide the ‘earth’ when on shorepower and the inverter should provide ‘earth’ when on inverter so that conductor should also be switched. 3 switched conductors for 120V single phase.
Otherwise you could possibly create a situation where the RV chassis could be energized depending on how you’re wired up. There’s a recent thread discussing how to confirm your inverter provides or does not provide N and G bond. You should read that.

Other than the inverter cable size question mentioned prior, that installation is pretty looking. Your wiring looks very well organized and clean. Goop that roof gland with paint or white elastomeric. Some are not as UV resistant as one might hope and become brittle.
 
What size wiring are you using to that inverter? A 1400W microwave will be pulling over 109A from the batteries, I hope you are using #2 or larger copper conductors… they appear small.
The company claims that they are approx 2 gauge. From the battery to the bus bar I am using 4 gauge, about 18" with the 4 gauge. Wire charts I have looked at show that is adequate. The only thing I would use the microwave for would be heating up a cup of coffee for 2 minutes. When testing it the wire never got warm to the touch. I have an infrared temp gauge and will be testing it every time I use the inverter and I will keep a close eye on it. I think I will run the microwave for about 10 minutes boiling a gallon of water and see how the wires perform.
 
Liking that transfer switch. Did I miss where you recounted the rating for it?

I noted that ‘position 2’ only has two wires. If I’m seeing that correctly the one concern is the bare/green/earth are not switched?

Shorepower should provide the ‘earth’ when on shorepower and the inverter should provide ‘earth’ when on inverter so that conductor should also be switched. 3 switched conductors for 120V single phase.
Otherwise you could possibly create a situation where the RV chassis could be energized depending on how you’re wired up. There’s a recent thread discussing how to confirm your inverter provides or does not provide N and G bond. You should read that.

Other than the inverter cable size question mentioned prior, that installation is pretty looking. Your wiring looks very well organized and clean. Goop that roof gland with paint or white elastomeric. Some are not as UV resistant as one might hope and become brittle.
The inverter I use uses an internal bond from the chassis ground to the 3 wire connector according to the seller. I tested it with an ohm meter and they were connected. The switch is good for 690v and 32 amps
 
The company claims that they are approx 2 gauge. From the battery to the bus bar I am using 4 gauge, about 18" with the 4 gauge. Wire charts I have looked at show that is adequate. The only thing I would use the microwave for would be heating up a cup of coffee for 2 minutes. When testing it the wire never got warm to the touch. I have an infrared temp gauge and will be testing it every time I use the inverter and I will keep a close eye on it. I think I will run the microwave for about 10 minutes boiling a gallon of water and see how the wires perform.
4 gauge may not heat up under full load, but the ampacity of the conductor is only 70A… it can limit the voltage to the inverter under load. I would upsize it to 2 or larger.
 
you could possibly create a situation where the RV chassis could be energized depending on how you’re wired up. There’s a recent thread discussing how to confirm your inverter provides or does not provide N and G bond. You should read that.
inverter I use uses an internal bond from the chassis ground to the 3 wire connector according to the seller. I tested it with an ohm meter and they were connected. The switch is good for 690v and 32 amps
Post 51 of this thread isn’t the thread I was referring to, but it does cover the issue.
The thread I was thinking of was specific to RVs but the principles are the same.

I’d have to draw out your excellent system to wrap my head fully around it, but it appears you have a redundant earth/green/bare situation that could carry voltage which is not desirable. If that is the case I think it’s as simple as a) not having N and G tied in the breaker box, and b) switching your earth/green/bare with the transfer switch (that appears to have spaces for that). @FilterGuy am I incorrect?
 
Post 51 of this thread isn’t the thread I was referring to, but it does cover the issue.
The thread I was thinking of was specific to RVs but the principles are the same.

I’d have to draw out your excellent system to wrap my head fully around it, but it appears you have a redundant earth/green/bare situation that could carry voltage which is not desirable. If that is the case I think it’s as simple as a) not having N and G tied in the breaker box, and b) switching your earth/green/bare with the transfer switch (that appears to have spaces for that). @FilterGuy am I incorrect?
Sorry I haven't responded, I have been working 12 hr shifts the last 2 days. Tomorrow I will explore this more fully and try and make a diagram of my set up.
 
4 gauge may not heat up under full load, but the ampacity of the conductor is only 70A… it can limit the voltage to the inverter under load. I would upsize it to 2 or larger.
I will order some 2 gauge wire and connectors tomorrow. I did notice a voltage drop when running the microwave. Tomorrow I will go out and run it again and get some numbers.
 
will order some 2 gauge wire
FWIW I used 00 ( 2/0 aka two-ott) for my battery>1200W inverter.
WAY overkill I know
a) I could use a bigger inverter without buying new cable and
b) voltage drop? what voltage drop?!!

For such a short run the extra cost isn’t that big of a deal. And it’s totally dependable!
 
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I will order some 2 gauge wire and connectors tomorrow. I did notice a voltage drop when running the microwave. Tomorrow I will go out and run it again and get some numbers.
I used 2/0 on the 2200w Giandel I installed in the backseat of my truck that hauls the truck camper. The inverter can feed 120V AC to the camper while driving to not only charge the battery but provide back up power in case the truck camper inverter has a problem.

The Giandel has a surge rating of 4000w for a few milliseconds and you should always upsize one size up after running the numbers (voltage, wire length and amp draw) thru a calculator.

Considering you planned on running a microwave, a 3Kw 24v system may have been a better choice. But many won't go that route because of being unfamiliar with 24V and it does require a step down to run 12V items and charging considerations can play into it. I consider that to be minor, most LED lighting will run up to 32V and charging would depend on the application. As for refrigeration, compressor fridges are readily available in 24V.
 
Post 51 of this thread isn’t the thread I was referring to, but it does cover the issue.
The thread I was thinking of was specific to RVs but the principles are the same.

I’d have to draw out your excellent system to wrap my head fully around it, but it appears you have a redundant earth/green/bare situation that could carry voltage which is not desirable. If that is the case I think it’s as simple as a) not having N and G tied in the breaker box, and b) switching your earth/green/bare with the transfer switch (that appears to have spaces for that). @FilterGuy am I incorrect?
I have been reviewing the excellent write-up and diagrams by @FilterGuy and I do believe you are correct about my grounding scheme. I will revamp and run the shore power ground thru the transfer switch. When on shore power the earth/ground will be thru the shore power ground, and when on inverter it will isolate the ground thru the inverter.
 
Just went out and recorded some voltage numbers when running the microwave. The inverter LED reads 13.0 Volts incoming with just the inverter on and no other loads. Turn on the microwave which pulls 109 amps and the voltage reading from the inverter LED now reads 11.9 volts. That is quite a bit of drop, or is that normal? I am going to order some 2 gauge wire and a battery cutoff switch today. I want to put the cutoff switch between the battery and the DC bus bar. Also rethinking the Anderson connector. Is it possible I am losing voltage thru that connector? If so I will just remove it and run the wires from the: battery terminals to the DC bus bar with the positive having a battery cut-off switch in place. Please give me your thoughts.
 
Turn on the microwave which pulls 109 amps and the voltage reading from the inverter LED now reads 11.9 volts. That is quite a bit of drop, or is that normal?
I forget. Are you using AGM or flooded lead acid batteries?

If so that’s not surprising but lower than I’d guess. 60 seconds of microwave; look at volts once microwave stops, snd then again 5 minutes later. The voltage drop you are seeing is because of the high amp load- at least in part.

If you are lithium then ya, that display voltage reading is significantly more of a drop than I’d expect since lithium batteries can do that high amp output way better than lead acid.

Weird thing: possibly your smaller gage battery cables may actually yield less visual drop on your inverter display than a more efficient 2/0 fat cable might.
Just because that ‘drop’ is mostly due to the load you applied. The battery will mostly ‘recover’ in five minutes after the load stops and settle to its more accurate static voltage.

Another fun thing: with batteries fully charged and full sun on your panels stick a quart of water in the microwave and observe your charge controller output to the batteries snd watch while you turn on the microwave. Especially at 20*F or lower.
 
I forget. Are you using AGM or flooded lead acid batteries?

If so that’s not surprising but lower than I’d guess. 60 seconds of microwave; look at volts once microwave stops, snd then again 5 minutes later. The voltage drop you are seeing is because of the high amp load- at least in part.

If you are lithium then ya, that display voltage reading is significantly more of a drop than I’d expect since lithium batteries can do that high amp output way better than lead acid.

Weird thing: possibly your smaller gage battery cables may actually yield less visual drop on your inverter display than a more efficient 2/0 fat cable might.
Just because that ‘drop’ is mostly due to the load you applied. The battery will mostly ‘recover’ in five minutes after the load stops and settle to its more accurate static voltage.

Another fun thing: with batteries fully charged and full sun on your panels stick a quart of water in the microwave and observe your charge controller output to the batteries snd watch while you turn on the microwave. Especially at 20*F or lower.
I have a 280 amp hour Lithium battery. Out looking at my set up, it appears I have 4 gauge wire from my battery to the anderson connector, then from the other side of the anderson connector I have the same wire that I cut off to shorten the inverter wire that came with the inverter. The seller claims it is equivalent to the 2 gauge and it appears much bigger than the 4 gauge.
 
appears I have 4 gauge wire from my battery to the anderson connector, then from the other side of the anderson connector I have the same wire
That is small.
The 350A Andersen appears to want 1AWG while the 175A wants at least 2 gage.
(to my way of thinking I would go at least 1ga)

The battery- since microwave is a seldom used item you say- is ok-ish. I’d probably get a second battery but you may not need it; I have a 24/7/365 mindset so that won’t apply to you. I have about 300Ah usable myself and that’s just barely one overnight this (low light) time of year.
 
That is small.
The 350A Andersen appears to want 1AWG while the 175A wants at least 2 gage.
(to my way of thinking I would go at least 1ga)

The battery- since microwave is a seldom used item you say- is ok-ish. I’d probably get a second battery but you may not need it; I have a 24/7/365 mindset so that won’t apply to you. I have about 300Ah usable myself and that’s just barely one overnight this (low light) time of year.
I am going to toss out the Anderson connector. I eventually will go with another 280 ah battery to add to the present one.
 
am going to toss out the Anderson
I support that. I think they’re great for a lot of things but I’ve seen them get ‘shiny and smokey’ feeding off-road recovery winches. I’ve never bought one.
 
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