diy solar

diy solar

What was your worse DIY solar mistake ever?

Subdood said:
That's why I'm still on a single phase inverter
Click to expand...
I have some 240 volt loads and some 3 wire shared neutral circuits so I need a split phase inverter. I have been messing with electrical circuits for fifty years and should have known better. I obviously shut down the breaker panel when changing out the L1 and L2. Hindsight is golden.
 
Subdood said:
Yikes that sounds bad. That's why I'm still on a single phase inverter, I'm afraid of not wiring the neutral right and frying my 120V circuits with a split phase inverter. Or I'm concerned the neutral in the inverter will 'go away' with similar bad results. I know I'm overly paranoid, and I'd be very careful about wiring stuff, but it does cross my mind more than once.
Click to expand...

Is your entire system 120V single phase? Or do you use it to back up a house with 120/240V split-phase from the grid?

Feeding 120V only to one leg of 120/240V can cause brownout and damage to some equipment. If you feed 120V to L1 and there are any 240V loads between L1 and L2, then 240V loads in series with L2 loads get 120V total, each load sees less than 120V which is brownout condition.

We can lose neutral in a grid-fed circuit as well. I did that as a kid, doing "hot work" connecting power to my workbench, I opened neutral which burned out a light bulb in the house.

In a commercial site with 120/208Y 3-phase feeding cubicles, lost neutral put 208V across a power strip, causing it to smolder due to surge arrestor. We were told not to plug heavy loads into the cubicle wiring. The organization had an office copier (10A or so) plugged in.
 
Hedges said:
Is your entire system 120V single phase? Or do you use it to back up a house with 120/240V split-phase from the grid?

Feeding 120V only to one leg of 120/240V can cause brownout and damage to some equipment. If you feed 120V to L1 and there are any 240V loads between L1 and L2, then 240V loads in series with L2 loads get 120V total, each load sees less than 120V which is brownout condition.

We can lose neutral in a grid-fed circuit as well. I did that as a kid, doing "hot work" connecting power to my workbench, I opened neutral which burned out a light bulb in the house.

In a commercial site with 120/208Y 3-phase feeding cubicles, lost neutral put 208V across a power strip, causing it to smolder due to surge arrestor. We were told not to plug heavy loads into the cubicle wiring. The organization had an office copier (10A or so) plugged in.
Click to expand...
I'm not sure I understand your question. But here is an answer. I have my inverter AC input tied to one leg of the pole (service) panel via a 60A DP breaker at the pole. I installed a DP breaker in case I wanted to put in another 6500EX for split phase. One hot, neutral and ground. The inverter's AC output feeds a critical loads sub panel, fed by one hot, neutral and ground, with no N/G bond in that panel.

I don't have all of the 120V circuits on that panel. The 7 circuits I did transfer came from the house panel. I fed the hots and neutrals for each circuit thru a conduit to the sub panel. The house panel does have the 120/240V feed from the pole panel, and it has all the 240V circuits and a few 120V circuits. I transferred the neutrals because I never updated the firmware for the 6500, so it didn't have a common neutral between input and output.

Most of the time the load on the inverter is a few hundred watts, unless we do laundry, and/or run the microwave or toaster oven, and then it might be 2KW total.
 
Last edited:
If inverter AC output only feeds a dedicated critical loads panel with 120V loads, not a panel with some 240V load, no problem.

The problem I was describing is when someone feeds 120V into an existing 120/240V panel like your main panel, e.g. when grid is down. There can be ways to make that work.

Is your critical loads panel meant for split phase, and you're only using every other breaker slot? If so you can feed both L1 and L2 busbars in the panel from 120V L1 of your inverter.
 
Hedges said:
Is your critical loads panel meant for split phase, and you're only using every other breaker slot? If so you can feed both L1 and L2 busbars in the panel from 120V L1 of your inverter.
Click to expand...
I have a 60A DP breaker feeding the bottom right slots of the panel. I tied the two hot posts together with a 6ga wire so I have the same voltage on both legs and use all the slots. It's a 12 slot panel, so I still have 3 slots left.

If I go split phase, I'll remove the jumper of course.
 
Last edited:
Hedges said:
We can lose neutral in a grid-fed circuit as well. I did that as a kid, doing "hot work" connecting power to my workbench, I opened neutral which burned out a light bulb in the house.
Click to expand...
My first electrical experiment was tying old receptacle plug wires to a loud speaker. Then I plugged it in.

Hilarity ensued..then smoke..
 
Last edited:
My first electrical experiment was tying old receptacle plug wires to a loud speaker. Then I plugged it in.
Subdood said:
Hilarity ensued..then smoke..
Click to expand...
I think i did that in like 1962.

Nice 60hz hmm until the coil went poof.

My parents weren’t pleased..
 
Last edited:
1201 said:
spending $10k on battery backup to save maybe $300 a year :cry::cry::cry:
Click to expand...
Tons of people spend $10k extra to get the fancier version of the same basic car, just to have heated memory seats and a big huge sunroof. When the power goes out for an extended period, which it will eventually, you'll be smiling. Those other people will have warm butts as they drive to your house.
 
bolhuijo said:
Tons of people spend $10k extra to get the fancier version of the same basic car, just to have heated memory seats and a big huge sunroof. When the power goes out for an extended period, which it will eventually, you'll be smiling. Those other people will have warm butts as they drive to your house.
Click to expand...
That's the idea in theory but the reality is that we lose power during winter storms when the house is using the most energy ever and there is no solar production. The battery will be drained in half a day then it's on to the generator, which one could just have bought the generator and skipped the battery and be in the same boat
 
1201 said:
That's the idea in theory but the reality is that we lose power during winter storms when the house is using the most energy ever and there is no solar production. The battery will be drained in half a day then it's on to the generator, which one could just have bought the generator and skipped the battery and be in the same boat
Click to expand...
I guess I was only thinking about my small house... Last time we spent a couple days in the dark I just hooked aux power to fridge, gas furnace, and TV. Very small bare minimum load.
 
So... I have these two Sharp 123 watt panels hung on the interior wall of my workshop.

'Prepper Art' and since the first day testing they've never seen sunshine.. . Just waiting for some needy situation.. .

Bought back in the days of five, six, seven dollar per watt PV, yeah.. . at $4.80 per watt they were never 'disposable : )
 
1201 said:
That's the idea in theory but the reality is that we lose power during winter storms when the house is using the most energy ever and there is no solar production. The battery will be drained in half a day then it's on to the generator, which one could just have bought the generator and skipped the battery and be in the same boat
Click to expand...
Actually the battery will make the generator more efficient. So still a good purchase.
 
1201 said:
That's the idea in theory but the reality is that we lose power during winter storms when the house is using the most energy ever and there is no solar production. The battery will be drained in half a day then it's on to the generator, which one could just have bought the generator and skipped the battery and be in the same boat
Click to expand...

Same boat here. Last time power went out was at 4am, and a family member needs a CPAP. I got to run outside to the solar trailer in my boxers while it was sleeting sideways, turn on the inverters, run to the garage and flip the transfer switch to generator, and then back to bed. Never did get back to sleep after that.

A full house generator and auto transfer switch would have involved waiting in bed for 30 seconds for it to do it's thing, and then going back to sleep. Would have cost about half what I spent on the solar power system too.

I knew from the beginning that I wasn't building this for any kind of cost savings. It was built out of the "fun" budget and treated as such. Just so happens that it does provide backup power, and has harvested just over half a MWh in the slightly over a a year it's been running.
 
Last edited:
Let's see I've been shocked a few times. Once was about 250 volts DC from my hand to my arm. That hurt. Another time I was changing wires in a combiner box and while holding a negative wire in my hand hey positive wire from the solar array came down and brushed my forehead and I saw a bright white light for a Split Second even after sundown and in the Twilight hours the array still made enough to make me see the light.

Another mistake I've made is not planning ahead enough so that my upgrade path is limited. I also had chance to start with 48 volt batteries and inverters but instead chose to start with 24 volt which ended up costing me more money in the long run.
 
You must log in or register to reply here.

Similar threads

kolek
Deciding to DIY my solar battery was one of my worst mistakes ever
7 8 9
Replies
166
Views
6K
Daddy Tanuki
Daddy Tanuki
J
Convert Upgrade Mistake
Replies
8
Views
427
jpcjtrtj
J
Unwin
EcoFlow Delta Pro Ultra issues
Replies
1
Views
898
AZ Solar Junkie
A
B
System Design Feedback
Replies
7
Views
273
Solar Guppy
Solar Guppy
S
Safe cheap transfer switching with LVD in small system
Replies
15
Views
337
SWSL
S
Back
Top