diy solar

diy solar

About to spend a lot of money tomorrow on this system (am I making a mistake?)

The Victron dealer weighed in about the 230V to 110V question with:

Your Ok,
So the Quattro 2 is not split phase plus it's not available. Shipments are not even in Holland yet. The Autotransformer is what gives you the split phase, you need to disable the Ground bond on the multiplus and run a DC ground jumper to the autotransformer. Pretty easy and then you have a true 120/240 output to run to your cabin. On the input side (generator) you have 240 L1 and L2 and ground but because it's straight 240 you don't have a neutral requirement.
On your LRA issue its a soft start variable speed HP so that is key here and it looks like its peak is around 5k. Is it water to water or water to air? I would typically look at your well pump and other loads as this heat pump will be on alot to see how much head room you have on the inverter sizing. The KVA gives you a number you can calculate power factor from. Look for PF on your data sheets and that will tell you more about what the inverter can do. if there is a traditional well pump it's probably a .8 PF so if it was 1000w you would need 1250VA of inerter..
 
That's good to know, thanks. It should be momentary during startup if it uses that much. And 8% left over should be more than plenty for any other loads we'd be running I think. In the winter I would imagine that GSHP will start and then just keep running the whole winter...
 
Single strand aluminium wire is bad. Multi strand high current is fine. Service entrance type wire as used to connect most homes to the pole.
Have you tried trenching yet ???
 
I might consider other inverters if somebody can point out that what I have selected won't work and why. Hopefully dealers trying to sell other equipment won't jump in here to confuse me even more while I try to figure this stuff out!

For a moment I thought you were starting out assuming an off-brand inverter, and considering upgrade to Victron.
Victron is a good brand, and has a split-phase solution. Apparently nothing UL listed, if that matters.

SMA equipment is UL listed. People who can afford it are happy with it. Competitive price for grid-tie, expensive battery inverters.
The AC coupling SMA generally uses is optimum when much power from PV will be used as AC immediately.

Assuming UL can be ignored, main question is what equipment meets performance needs, including surge and operating wattage, and battery charge current, over operating conditions. Hot weather (doesn't apply to you) and condensation would main issues. Some Victron equipment (charge controllers) are potted, so should be immune to humidity.

SMA also talks to Pylontech batteries.


"On your LRA issue its a soft start variable speed HP so that is key here and it looks like its peak is around 5k. Is it water to water or water to air? I would typically look at your well pump and other loads as this heat pump will be on alot to see how much head room you have on the inverter sizing. The KVA gives you a number you can calculate power factor from. Look for PF on your data sheets and that will tell you more about what the inverter can do. if there is a traditional well pump it's probably a .8 PF so if it was 1000w you would need 1250VA of inerter."

GSHP may be soft-start because variable speed. Perhaps an internal pump is also.
If there is a "traditional well pump", although a 1000W pump in his example might need 1250VA out of the inverter's total rating, it is going to need about 5x rated current (or "LRA" if available) to start. That's 6kVA for a moment. Decent size inverter could do that. If bigger pump, needs more according to that calculation.
 
Yes, that's correct. The heat pump is the only 230V load.
Even if you found a resistive load that is meant for a 20 amp branch circuit the un-balanced load is still within spec.
Just make sure the high draw 120VAC loads are balanced across the phases in the panel.
Its how this stuff is meant to work.
 
For a moment I thought you were starting out assuming an off-brand inverter, and considering upgrade to Victron.
Victron is a good brand, and has a split-phase solution. Apparently nothing UL listed, if that matters.

SMA equipment is UL listed. People who can afford it are happy with it. Competitive price for grid-tie, expensive battery inverters.
The AC coupling SMA generally uses is optimum when much power from PV will be used as AC immediately.

Assuming UL can be ignored, main question is what equipment meets performance needs, including surge and operating wattage, and battery charge current, over operating conditions. Hot weather (doesn't apply to you) and condensation would main issues. Some Victron equipment (charge controllers) are potted, so should be immune to humidity.

SMA also talks to Pylontech batteries.


"On your LRA issue its a soft start variable speed HP so that is key here and it looks like its peak is around 5k. Is it water to water or water to air? I would typically look at your well pump and other loads as this heat pump will be on alot to see how much head room you have on the inverter sizing. The KVA gives you a number you can calculate power factor from. Look for PF on your data sheets and that will tell you more about what the inverter can do. if there is a traditional well pump it's probably a .8 PF so if it was 1000w you would need 1250VA of inerter."

GSHP may be soft-start because variable speed. Perhaps an internal pump is also.
If there is a "traditional well pump", although a 1000W pump in his example might need 1250VA out of the inverter's total rating, it is going to need about 5x rated current (or "LRA" if available) to start. That's 6kVA for a moment. Decent size inverter could do that. If bigger pump, needs more according to that calculation.
Thanks for all this info.

We are very off grid and we have no building codes. So I don't think UL matters since I mostly see that associated with grid tied stuff, but I could be wrong.

If I'm reading what you wrote correctly, how did you come to the conclusion that the ClimateMaster Trilogy 45 q-series two-ton GSHP peaks at 5KW with soft start? That's great info to know but somebody else here had come to the conclusion that it took up to 92% of the 8KW from the Multiplus. The GSHP will use fluid from a buried horizontal loop.

The inverter we're using is the Multiplus II that can supply 8KW.
 
Just make sure the high draw 120VAC loads are balanced across the phases in the panel.
Its how this stuff is meant to work.
Balancing loads across the panel... Does that mean the architecture of the C/B box or panel? Or does that mean not flipping on an induction stove in the cabin and a microwave unless they're on two separate circuits that are balanced in the C/B box or panel?

I will hire an electrician for this part of it at the cabin. I just want to make sure the equipment I get can support it. Victron is telling me with the AutoTransformer at the cabin all will be well. Victron dealer told me:

Your Ok,
So the Quattro 2 is not split phase plus it's not available. Shipments are not even in Holland yet. The Autotransformer is what gives you the split phase, you need to disable the Ground bond on the multiplus and run a DC ground jumper to the autotransformer. Pretty easy and then you have a true 120/240 output to run to your cabin. On the input side (generator) you have 240 L1 and L2 and ground but because it's straight 240 you don't have a neutral requirement.
On your LRA issue its a soft start variable speed HP so that is key here and it looks like its peak is around 5k. Is it water to water or water to air? I would typically look at your well pump and other loads as this heat pump will be on alot to see how much head room you have on the inverter sizing. The KVA gives you a number you can calculate power factor from. Look for PF on your data sheets and that will tell you more about what the inverter can do. if there is a traditional well pump it's probably a .8 PF so if it was 1000w you would need 1250VA of inerter..
 
Thanks for all this info.

We are very off grid and we have no building codes. So I don't think UL matters since I mostly see that associated with grid tied stuff, but I could be wrong.

If I'm reading what you wrote correctly, how did you come to the conclusion that the ClimateMaster Trilogy 45 q-series two-ton GSHP peaks at 5KW with soft start? That's great info to know but somebody else here had come to the conclusion that it took up to 92% of the 8KW from the Multiplus. The GSHP will use fluid from a buried horizontal loop.

The inverter we're using is the Multiplus II that can supply 8KW.

Page 29. Which model?

20A * 230V = 4600W
32A * 230V = 7360W
 
If I'm reading what you wrote correctly, how did you come to the conclusion that the ClimateMaster Trilogy 45 q-series two-ton GSHP peaks at 5KW with soft start?

I didn't, only said "may be soft start". Thought someone might have mentioned it. 5kW/6kVA was just using the example you quoted from vendor for a pump.
The manual mentions variable speed circulation pumps, but haven't spotted anything like that for compressor. It does mention avoiding short-cycling of the compressor, which seems to indicate that is only on/off.

I haven't found electrical specs yet, checking index and thumbing through.
Does it list "LRA"? If not, assume 5x rated current, which inverter surge rating has to provide.

Page 29. Which model?

20A * 230V = 4600W
32A * 230V = 7360W

Assuming no gentle ramp up from VFD running compressor,
Either 100A 23kW surge or 160A 36.8kW surge.
Either Victron or SMA can have multiple inverters stacked to reach that.

There are soft-start kits people here have used for AC powered my small generator or inverter. That could let you get by with less, if compatible with this compressor.
 
Balancing loads across the panel... Does that mean the architecture of the C/B box or panel? Or does that mean not flipping on an induction stove in the cabin and a microwave unless they're on two separate circuits that are balanced in the C/B box or panel?
Its an electrician thing.
This is all in a days work for an electrician and for the most part the user doesn't even know a thing about it.
Since you are your own power company, your users are going to have to learn that they can't turn everything on at the same time because you don't have a nuclear power plant anyways.
So phase balance is down the list of issues.
 
Last edited:
Page 29. Which model?

20A * 230V = 4600W
32A * 230V = 7360W
We've been planning for the model 0930. Based on PVWatts and 22KW of bifacial panels optimum for the winter (straight up and down) no shade from terrain or trees and perfectly aligned south, using the soil temp data we could find, and average temps for our location, we think this solar array will allow us to rarely have to use the wood stove in January. And if we take a trip and leave the cabin in the coldest part of the year, we think the solar with a generator backup should be able to keep the cabin above freezing. Going to be interesting to see how this works out.

But we're going to have a couple backups. Generator with a month's supply of gas in an external tank to power everything and a Toyo stove or something else that will kick on if it has to. Of course I need to next make sure the Honda 7000 will work with this array...

The best laid plans of mice and men...
 

Attachments

  • power.jpeg
    power.jpeg
    194.2 KB · Views: 6
Last edited:
This is kind of off topic but has anyone ever considered using structural aluminum above ground as a conductor? You can get 24' lengths and weld or bolt them together. I just bought several hundred feet of 2x2x1/8wall HSS for ~$4/ft . Its cross section of aluminum is just under 1". They could easily be installed on posts at a safe height with inexpensive insulators.

Edit: They were 20' not 24'
Wow. Several hundred feet of aluminum HSS? And relatively big HSS! I don't think I would use it that way, but.... Did you buy it with something else in mind?
 
I didn't, only said "may be soft start". Thought someone might have mentioned it. 5kW/6kVA was just using the example you quoted from vendor for a pump.
The manual mentions variable speed circulation pumps, but haven't spotted anything like that for compressor. It does mention avoiding short-cycling of the compressor, which seems to indicate that is only on/off.

No surge:

1642787049473.png


We've been planning for the model 0930. Based on PVWatts and 22KW of bifacial panels optimum for the winter (straight up and down) no shade from terrain or trees and perfectly aligned south, using the soil temp data we could find, and average temps for our location, we think this solar array will allow us to rarely have to use the wood stove in January. And if we take a trip and leave the cabin in the coldest part of the year, we think the solar with a generator backup should be able to keep the cabin above freezing. Going to be interesting to see how this works out.

But we're going to have a couple backups. Generator with a month's supply of gas in an external tank to power everything and a Toyo stove or something else that will kick on if it has to. Of course I need to next make sure the Honda 7000 will work with this array...

The best laid plans of mice and men...

Okay, then 4600W peak. Yay.
 
Well nobody trashed the Victron dealer who told me the AutoTransformer (placed in Location A) would solve the problem of powering the GSHP and providing 120V to the cabin. So it seems that this should work.
No surge:

View attachment 80668

Okay, then 4600W peak. Yay.

Assuming no gentle ramp up from VFD running compressor,
Either 100A 23kW surge or 160A 36.8kW surge.
Either Victron or SMA can have multiple inverters stacked to reach that.

There are soft-start kits people here have used for AC powered my small generator or inverter. That could let you get by with less, if compatible with this compressor.

Thank you fellas for digging into that. @Hedges do you agree the most that GSHP will demand is 4600W which is no issue for the Multiplus supplying 8KW?

I sure appreciate you guys keeping me out of trouble by providing your generous expertise and making this forum a goldmine for dummmies like me.
 
Back
Top