Am looking for some electrical code help

[LBen]

I'm back looking for guidance from the great and powerful members of this forum.

I've got what I'm calling a phantom voltage.

I've completed all of the wiring and equipment installation. The 9.7 kW array was pushing 9+ kW into the batteries a couple days ago as a test.

I was working down the AC part of the Sol-Ark commissioning checklist when I came across my phantom voltage. Once AC power has been applied to the Grid terminals the checklist says to check for 240v between L1 and L2, 120v between L1 and N and L2 and N, 0v between Neutral and Ground and then 0v between Grid L1 and Load L1 and Grid L2 and Load L2. Well, every thing else checks, but I have approximately 70v between Grid L1 and Load L1 and likewise between Grid L2 and Load L2. The Load circuit breaker is off. I have a xfer switch installed so that I can switch the house from the utility or Sol-Ark output. I have to this point continued to run the house off of the utility - I have not moved the xfer switch to supply the house with the Sol-Ark so the Load wires have not been powered yet. I disconnected the Sol-Ark Load wires at the Sol-Ark and at the xfer switch. When I connect power to the Grid connection of the Sol-Ark I still see the 70v phantom voltage as described.

So am I seeing induced voltage in those wires? Is this normal? If not, any ideas on how to get rid of it?

Thanks for any ideas,
Lowell

 

[zanydroid]

Can you link the checklist?

Hmm. Are you using high impedance or low impedance mode on the multimeter?

0V between grid L1 and Load L1 to me implies that they are bonded. Same for the L2. Not-zero implies to me that the grid is not connected and/or the inverter is off.

I think it's possible to have induced AC voltage on any floating part of a circuit as a consequence of physics. If you have load breaker off and inverter off, and the grid relay is open, I think load L1/L2 are pretty floating.

What is the voltage between ground and Load L1, ground and Load L2?

 

[Hedges]

Try loading the 70V voltages with an incandescent light bulb, see if that pulls it to zero volts.

Hey, is "ground" grounded?
What are grid L1 and grid L2 connected to?

Usually we hear about PV panels carrying about 60 Vrms, but one guy with inverter in an RV and panels on ground mount ended up wagging the dog (dog's tail didn't wag, he wasn't happy.)

I only expect 0V between Grid L1 and load L1 if inverter is passing through Grid to Load. Which I think it will do when grid is present, depending on programming perhaps. Do you have a disconnect between grid and SolArk?

 

[LBen]

Can you link the checklist?

Apologies for delayed reply. Have been talking with Sol-Ark tech support. Apparently there is 12k test steps in the 15k manual. So I get into trouble trying to follow the damn manual.

Spent a long time on the phone working with the tech support guy. Sent him a video so he could see the 70v I was seeing. He had me do various voltage checks. Then all though the Load terminals were not connected to any load (xfer switch is in the utility position) he had me flip the Load breakers on and then had me check all of the voltages again. All was as it was supposed to be and he said that the SA was working properly.

I still have some concern about the phantom voltages I was seeing. I'm also wondering about how the neutrals are run. The neutral coming in from the service pedestal is branched to the Sol-Ark, the main panel and the generator. The neutral is not run through the xfer switch, AC disconnect or PM boxes. Input from this forum and an electrical forum indicated that neutrals did not need to be run with switch loops. I had an electrician come out several days ago to look at what I had. He said that I should have neutral wires looped along with the L1/L2 circuit paths. Said that was how he was taught. So I don't know. Should I run neutral wire loops?

Thanks for comments!

Hmm. Are you using high impedance or low impedance mode on the multimeter?

It is a Craftsman auto-ranging digital unit, 15+ years old. Can't change impedance modes and I don't know how it is wired up internally.

0V between grid L1 and Load L1 to me implies that they are bonded. Same for the L2. Not-zero implies to me that the grid is not connected and/or the inverter is off.

I think it's possible to have induced AC voltage on any floating part of a circuit as a consequence of physics. If you have load breaker off and inverter off, and the grid relay is open, I think load L1/L2 are pretty floating.

That is pretty much the conclusion that the tech support guy had. Once everything was powered up and the Load breakers were on, voltages looked as they should.

What is the voltage between ground and Load L1, ground and Load L2?

Tech support guy had me check Load L1/L2 and neutral and a small voltage (less than 5v) was present. Next time I power things up I'll check with them wrt to ground.

Hey, is "ground" grounded?

The ground/neutral bond is done at the service pedestal. The feeder is a 4 wire setup. L1/L2/N/G. Ground goes to a Ufer.

What are grid L1 and grid L2 connected to?

From the SolArk, the grid L1/L2 path goes through an AC disconnect, then the production meter, then to a 200 amp breakered disconnect at the service pedestal.

I only expect 0V between Grid L1 and load L1 if inverter is passing through Grid to Load. Which I think it will do when grid is present, depending on programming perhaps.

This goes back to the bad test steps in the manual. I shouldn't have been doing the checks with the Grid terminals powered.

Do you have a disconnect between grid and SolArk?

Yes

Checklist I was following is on page 22 in the Sol-Ark 15k-2P Manual https://www.sol-ark.com/wp-content/uploads/15K-2P_Manual.pdf

2.10 Powering-up and Testing the Sol-Ark

TURN ON the inverter with at least one power source: 1) Battery, 2) PV or 3) Grid

1.Check the voltage of the battery bank
A. Voltage of the battery must be between 43Vdc - 63Vdc.
B. If applicable, turn ON internal switches of the batteries. Measure individual voltages.
C. Verify that the voltage of the battery bank at the Sol-Ark terminals is adequate.

2. Check the voltage of each PV input circuit
A. Input voltage must not exceed 500Vdc.
B. Input voltage must be above the startup voltage of 125Vdc.
C. Do not ground PV+ or PV-.
D. Verify polarity in each PV string. Backward polarity will measure 0Vdc by the Sol-Ark and will cause long term damage.
E. PV input will only turn on the LCD screen. Inverter requires grid power and/or batteries to start inverting.
F. PV DC disconnect switch on the side of the inverter will turn the PV ON or OFF.
Figure 21: Built-in PV DC disconnect

3. Check GRID input voltage (Some of these steps are 12k content. These steps are intended to check that AC power is available to the SA, not to actually power the SA. For the 15k, as soon as AC power appears on the Grid terminals, it partially powers up. It also beeps cause it is not happy that a battery is not connected. At this point, the SA 15k was not supposed to be powered.)
A. Use the terminal lugs to measure AC voltages with a multimeter.
B. Measure line (L) to neutral (N) voltages on “GRID” terminal. Ensure 120Vac on both phases.
C. Measure line (L1) to line (L2) voltage on “GRID” terminal. Ensure 240Vac. (If voltage reading is close to 220V or 210V, verify if grid is single-phase or three-phase instead).
D. Verify that voltage between neutral and ground is 0Vac.
E. Verify that voltage between “GRID” L1 and “LOAD” L1 is 0V. Do the same for L2.

4. Power ON Sol-Ark 15K-2P-N
A. Turn ON the battery breaker.
B. PRESS down the power button to the ON position. Wait for the “Normal” LED indicator to turn on. This may take a few minutes.
C. Turn ON the PV DC disconnect switch. Wait for “DC” LED indicator to turn on.
D. Turn ON the “GRID” breaker. Wait for “AC” LED indicator to turn on. (This doesn't apply to the 15k, there is no Grid breaker.)
E. Turn ON the “LOAD” and “GEN” breakers.

 

[LBen]

Requested an inspection last nite. Inspector shows up at about 9 this morning - I was somewhat surprised.

I did not pass. But what he flagged me on are easy fixes - kinda. Had to add some conduit anchors - done. He wanted the plastic bushings on some conduit connectors even though these had beveled and polished throats - done. I got his opinion as to what labels to put on the inverter - done. He says that my 6 FMC runs need to be supported. Length each are less than 3', but he says FMC has different support requirements. Ok. He admitted he didn't know how I was going to do this - and I agree, still trying to figure out how to do it. He did not like the single EG4 battery I had sitting on the top of each 3 rack. He gave the option of either figuring out how to protect the battery cable or just remove the batteries. Ok.

He did not have an issue with having a white PV wire. I had managed to bundle the PV wires so that they were only visible at the array and in the inverter box. He did not have a issue with running the PV wires with the other AC wires in the raceways - that was good.

He said he would have to research in the NEC if it was okay to not run neutral wires along the switch loops, but said I was probably ok. Will have to wait and see what he determines.

Then I need to seal the conduits running through the walls with what is called Duct Seal. This is a putty like material - will do a poor job of sealing those conduits. Does anyone know of a code compliant spray foam? He said there is no such thing approved by code. Funny thing is that when building this house the building inspector had me follow up on places the electricians had missed and use a spray foam material (think it was called fire blocker) where wires passed through headers, sill plates and the such.

He also wanted a map placard showing the location of the generator and where the DC disconnects are out at the array. I'll have to have a custom one made by PVLabels.

Almost done with state. Still have PoCo and county to deal with - but I don't expect any major show stoppers with either of them.

 

[zanydroid]

He says that my 6 FMC runs need to be supported. Length each are less than 3', but he says FMC has different support requirements.

There are these universal that are not cheap but explicitly listed for FMC.

Mighty-Hold Universal Clamp Strap, 1 hole, Steel, Cor-Shield® Polyolefin Coated

The Cor-Shield® Polyolefin coated one piece clamp back and strap secures both cable and conduit. The UCSC series secures EMT, Rigid, IMC, Metallic Liquid Tight, Nonmetallic Liquid Tight, FMC, and Schedule 40 and Schedule 80 PVC conduit, as well AC/MC Cabl

www.bptfittings.com

And then there is also using EMT clamps (1 or 2 sizes up)

The mighty hold grips better but EMT probably is good enough for supporting. Not sure about securing — it is loose

 

[zanydroid]

This is a putty like material - will do a poor job of sealing those conduits.

I have seen it in stores. I think it would end up looking better than spray foam.

 

[pvgirl]

Then I need to seal the conduits running through the walls with what is called Duct Seal. This is a putty like material - will do a poor job of sealing those conduits.

The ability for it to seal will depend on how well it is packed around the wires, and the sides of conduits. Also it can be removed if needed in the future. It's not expensive product so using plenty isn't a big deal. https://www.homedepot.com/p/Gardner-Bender-5-lbs-Plug-Duct-Seal-Compound-DS-530/310616351

 

[LBen]

The mighty hold grips better but EMT probably is good enough for supporting. Not sure about securing — it is loose

Yes, securing is the major issue. Was cogitating (with help from a beer) on solutions as I sat on a stool looking at the situation. One end of the FMC is attached to the side of a vertically mounted gutter. Going into the SolArk the FMC is attached to a horizontal surface. This is 1.5" FMC and with 2/0 wire in it, it is stiff and very hard to move over the 30+ inch length. Also the turning radius is relatively tight, so that stiffens things up alot. They all kinda group together as they pass by each other in their respective runs. Think I will have to split them into two groups. I'm thinking I may use some leftover uni-strut with the EMT clamps and some blocking off of the wall to attach get 4 of them secured. Then for the last 2 I'm gonna have to fab some kind of wood block that comes off of the wall at an angle to catch them with a short piece of uni-strut with EMT clamps. Or I might use the screw on conduit straps since I have a little more room on the lower end. It is gonna be a fight to do it no matter how I do things. I'm thinking the inspector will be ok as long as I make a decent effort at it.

The ability for it to seal will depend on how well it is packed around the wires, and the sides of conduits.

I've got a package of it on the table. The conduits have about 10 wires going through each one. Four of them are 2/0 in each conduit, then there are 4awg, 10 awg, a 1/0, signal wires and battery charging wire going to the generator, etc. Just a bunch of conductors. I'll do my best to poke the putty in there, maybe use a short piece of dowel rod to jam it in there. Expandable spray foam is so much quicker and easier, but not an approved method - oh, well.

Forgot to mention, the inspector did get his tape measure out. He did point out that my interior gutter which is under the main breaker panel sticks out more than 6". He also said I was marginal on the 36" side to side working space in front of the panel. I pointed out that the battery racks were on wheels and I could slide the one rack a little further away. He then said he was ok with the distances.

 

[zanydroid]

Yes, securing is the major issue. Was cogitating (with help from a beer) on solutions as I sat on a stool looking at the situation. One end of the FMC is attached to the side of a vertically mounted gutter. Going into the SolArk the FMC is attached to a horizontal surface. This is 1.5" FMC and with 2/0 wire in it, it is stiff and very hard to move over the 30+ inch length. Also the turning radius is relatively tight, so that stiffens things up alot. They all kinda group together as they pass by each other in their respective runs. Think I will have to split them into two groups. I'm thinking I may use some leftover uni-strut with the EMT clamps and some blocking off of the wall to attach get 4 of them secured. Then for the last 2 I'm gonna have to fab some kind of wood block that comes off of the wall at an angle to catch them with a short piece of uni-strut with EMT clamps. Or I might use the screw on conduit straps since I have a little more room on the lower end. It is gonna be a fight to do it no matter how I do things. I'm thinking the inspector will be ok as long as I make a decent effort at it.

Can you share a photo of the problem location?

 

[Balrog006]

I really have no idea what to expect from this inspector. I am not going to entertain the idea of pulling a single 10awg 220' just cause he doesn't like the color of the jacket.

Feel free to cite for him and discuss, engage calmly and civilly-however the inspector’s word and decision is in a vast majority of cases final and irrefutable. Good thing he didn’t see, notice or care apparently.

If he had said no go and has an issue with the jacket color-despite your best efforts-in order to get a passing inspection and a final sign off-you will pull whatever color wire he requires.

 

[LBen]

Time to close this thread out, with once again my thanks to the folks on this forum who offered advice.

I corrected the items the state guy pointed out in his inspection and sent pictures. He did not come back out to reinspect. He sent an email saying that I had passed and later that night I got the official state sign off on the permit.

The PoCo guy was out the next day (state system sends notifications to the power companies). He initially said that I did not have the meter socket wired correctly. I went through the wiring with him, he then agreed that I was indeed wired properly. He put a net meter in the service pedestal and a production meter in the other meter socket. I switched on the AC side of the inverter and after a few minutes the inverter started to shove about 7 kWh into their grid and the production meter showed the power being fed to the grid.

Later that day the county guy showed. He pretended to look at the array, pulled the permit docs out of the bucket, said I would get the official signoff the following week - and drove off. Didn't look at the battery installation.

DC side of the system had been running for about 3 weeks. The AC side (with the DC) has been running for 1 week now and I've been tweaking some settings on the inverter. Batteries are seeing about 30% DOD overnite. Batteries are completely recharged by 10:30 in the morning. Not sure if I believe the readings on the inverter. On average the house consumes 22 kWh in a 24 hour period per PoCo monthly statements. On a good day the system is generating 54 kWh of power. Yesterday was a bright and cool day. My 9.7 kW array was putting out 10.4 kW at one point. System is a at an elevation of 8200'. Will be interesting to see output values on a -20 deg day with snow cover on the ground.

We have had two snow events so far this winter season. I gotta come up with a better way of removing snow from the array. A broom with a 6' extension handle is still about 2' too short to easily reach all the way to the top.

 

[GregM]

Same here in NM dealing with Socorro Electric Coop

 

[Balrog006]

Time to close this thread out, with once again my thanks to the folks on this forum who offered advice.

I corrected the items the state guy pointed out in his inspection and sent pictures. He did not come back out to reinspect. He sent an email saying that I had passed and later that night I got the official state sign off on the permit.

The PoCo guy was out the next day (state system sends notifications to the power companies). He initially said that I did not have the meter socket wired correctly. I went through the wiring with him, he then agreed that I was indeed wired properly. He put a net meter in the service pedestal and a production meter in the other meter socket. I switched on the AC side of the inverter and after a few minutes the inverter started to shove about 7 kWh into their grid and the production meter showed the power being fed to the grid.

Later that day the county guy showed. He pretended to look at the array, pulled the permit docs out of the bucket, said I would get the official signoff the following week - and drove off. Didn't look at the battery installation.

DC side of the system had been running for about 3 weeks. The AC side (with the DC) has been running for 1 week now and I've been tweaking some settings on the inverter. Batteries are seeing about 30% DOD overnite. Batteries are completely recharged by 10:30 in the morning. Not sure if I believe the readings on the inverter. On average the house consumes 22 kWh in a 24 hour period per PoCo monthly statements. On a good day the system is generating 54 kWh of power. Yesterday was a bright and cool day. My 9.7 kW array was putting out 10.4 kW at one point. System is a at an elevation of 8200'. Will be interesting to see output values on a -20 deg day with snow cover on the ground.

We have had two snow events so far this winter season. I gotta come up with a better way of removing snow from the array. A broom with a 6' extension handle is still about 2' too short to easily reach all the way to the top.

So far I like this tool from Amazon.
EVERSPROUT Never-Scratch SnowBuster 6.5-to-18 Foot (Up to 24 ft Standing Reach) | Pre-Assembled Extendable Roof Rake for Snow Removal | Lightweight Aluminum, Soft Foam Pad | Exclusive Push/Pull Design https://a.co/d/8j7T53u

They have 12, 18 and 24’ pole options.