Inverter Grounding

[Sunking]

OP please throw away the Manufactures Instructions. You will soon learn it is garbage and dangerous. I can help you but you must answer a few questions I need answers to. I will make you a detailed wiring diagram, and it will be safe.

1. Exactly how did you intend to wire the AC Output from the Inverter? This is a Hard-Wired inverter rather than Plug-N-Cord.

2. Sounds like you want to run a water pump with it?

3. Water Pump normally runs on commercial AC?

4. How do you plan to switch from commercial AC to Inverter?

5. Do you have a DMM and know how to read resistance?

[Sunking]

I AM GOING TO RAISE A BIG STINK. I sure hope it gets reported to the MODS.

OP tear that owners manual up. I am appalled at the gross negligence and incompetence of Morningstar. There Instructions are extremely DANGEROUS

REFERENCE owners manual page 7 and 9 of installation instruction. There are some Moderators and Members here who know electrical codes, why and when grounding is required, and where it is FORBIDDEN. So have a look. Your Jaws should hit the table.

On Page 7 details the AC Wiring. Observe it is a Hard Wired device and AC is 2-Wire Line and Neutral. It does not supply a Equipment Ground Conductor. Now follow the 4 Steps and I paraphrase:

1. Terminate a Black 12 AWG Line to AC Load or Distribution Panel
2. Insert 3-Amp Fuse in Black Line Conductor in step 1
3. Terminate a White 12 AWG Neutral conductor to Ac load or Distribution Panel
4. Terminate White Neutral Wire to Earth Ground using 12 AWG Green wire.

Violates all known electrical codes. But hang on because now it gets deadly dangerous on page 9 DC Instructions

All I am going to say here is take note this is a 300-watt Inverter. Look at the DC fuse size and note 100-Amps. Now go to Page 10 and see the full circuit. Can you believe what you see coming from an Equipment Manufacture. Where is my Lawyer?

[jeffy104]

Without good reason or extenuating circumstances, follow written instructions from those who build equipment you're using.

Are these flat plate collectors or evacuated tube type, or thermosiphon maybe ?

Where are you located and how far above sea level are you ?

I've also never observed or heard of panels breaking under snow loading. Have you had any failures due to snow loads ?

The little thing you describe is called a rotometer. It's a type of flow meter.

One possible, but not only help for the overheating you describe would be to increase the slope of the collectors to something closer to the ideal tilt for winter collection. If nothing else, that would also improve the winter heat production.

These aren’t vac tubes. They’re from Germany and the heating system is from Austria. I’m 1500’ above sea level I think. In the Adirondacks. Buildings get flattened all the time here from snow load. As the winter goes on the ice forms under the snow and it can be a foot thick on roofs- mostly just from compaction. Most I’ve seen is 48” in one day and that was on top of the 30” we already had. All that weight will easily shatter a solar panel. If I win the lottery I’ll change the angle of the panels- they’re on a roof. Temps here get to 35 below zero F in the winter. Wind chills can be negative 60F. The high today 6/1/20 is going to be 58. It was about 34F this morning but the house was about 72- solar heat.

[J.P.M.]

Yes these are glycol filled panels for heat. I’ve seen them over 400 degrees when a pipe blew out when the installer forgot a clamp. The relief valve is part of a larger gadget that monitors the incoming and outgoing glycol and adjusts the pump speed to suit conditions. The problem with temperature is AFTER the pressure is relieved. It keeps climbing and then, of course, the glycol is cooked and is no good any more. Another expense. I’m eliminating all this hassle by putting an automatic standby power system on the pump in order to keep the panels cool. When the power fails, the inverter will deliver ac power immediately. Some days it runs at 190F and some days 140F. It only draws .97 amps 120vac at full speed. Theres a little thing that looks like the glass on the old fashioned gas pumps that tells you what the flow rate is. I cover there panels in the winter to keep many feet of snow from breaking the glass- they are on a low pitch and there’s not enough sun anyway. I’ve never posted here before. I like the idea of not having a ground- less work but the manufacturer says to never operate without a ground. They didn’t say anything else about it but I like the idea going to the same ground rod that the panel is grounded to.

Without good reason or extenuating circumstances, follow written instructions from those who build equipment you're using.

Are these flat plate collectors or evacuated tube type, or thermosiphon maybe ?

Where are you located and how far above sea level are you ?

I've also never observed or heard of panels breaking under snow loading. Have you had any failures due to snow loads ?

The little thing you describe is called a rotometer. It's a type of flow meter.

One possible, but not only help for the overheating you describe would be to increase the slope of the collectors to something closer to the ideal tilt for winter collection. If nothing else, that would also improve the winter heat production.

[jeffy104]

Yes these are glycol filled panels for heat. I’ve seen them over 400 degrees when a pipe blew out when the installer forgot a clamp. The relief valve is part of a larger gadget that monitors the incoming and outgoing glycol and adjusts the pump speed to suit conditions. The problem with temperature is AFTER the pressure is relieved. It keeps climbing and then, of course, the glycol is cooked and is no good any more. Another expense. I’m eliminating all this hassle by putting an automatic standby power system on the pump in order to keep the panels cool. When the power fails, the inverter will deliver ac power immediately. Some days it runs at 190F and some days 140F. It only draws .97 amps 120vac at full speed. Theres a little thing that looks like the glass on the old fashioned gas pumps that tells you what the flow rate is. I cover there panels in the winter to keep many feet of snow from breaking the glass- they are on a low pitch and there’s not enough sun anyway. I’ve never posted here before. I like the idea of not having a ground- less work but the manufacturer says to never operate without a ground. They didn’t say anything else about it but I like the idea going to the same ground rod that the panel is grounded to.

[Sunking]

No ground required. If you insist must go to AC Service ground.

[J.P.M.]

Are these PV panels or solar thermal collectors ?
What type of setup do you have that will get a (PV?) panel up to 375 F. ?
If thermal, it's possible to get to 375 F, but not likely and not often unless you have a selective surface on the panels or you're augmenting the irradiance with mirrors or some such scheme.
Usually a P & T relief valve will lift, probably from temp. before a solar panel gets that hot. Mine will lift at ~ 200 F if I stagnate the system for any reason.

This is sounding vaguely familiar to me. Have you been here before, maybe a long time ago ?

[jeffy104]

Grounding help- I’m going to install a 300 watt Morningstar SureSine pure sine wave Inverter to use as a backup ac power source for the cooling pump on my solar panels. I am on the grid and the panels are for heat and they quickly overheat to about 375 F when the power goes out on a sunny day. I have a couple 12v batteries to power the inverter. My question is: Can I ground the inverter to the same ground cable that my service entrance is connected to or is there a reason for making a separate ground.