Safe Grid Use of the 5000ES and transformer

[Zwy]

I don't really know what type of pump controller. it's a Franklin Electric Pumptec controller.. There's a big capacitor inside the box.

Basically just a pump controller with a capacitor to provide the 3rd phase to kick the 3 phase pump spinning. This will have a high starting surge for a few milliseconds, just like all the 3 phase pumps. Running is 7A load, I would think the initial current surge would be 28A or less for a few milliseconds.

Tank float switch in water tank that is currently connected to a 2 pole 240V contactor with a 120V control coil. (I've just ordered a 240V control coil contactor to not rely on the grid). I also still have pressure switch as a back up in case something happens to the water tank, I can shut off water to the storage tank and pressurize the pipe from the well pump again.

Looks like you have that figured out.

New issue today: I connected 5 (395W, 48Voc) solar panels in series, installed all the mc4 connectors, high-voltage disconnect to the Growatt. The Growatt doesn't show any solar pv array connected to it. I wasn't sure how safe it is to check connectivity on a series of PVs? I'm planning to go check the continuity after sundown.

I had a pair of MC4 connectors with about a 6 inch long wire that I clipped off the retainer locks so I could easily plug into a connector and disconnect. Do not touch both wires at the same time and keep the leads short so the ends can't get close enough to arc. Ensure the multimeter is rated for the voltage you will be working with.

I checked polarity on each panel first, wrote on the backside of the panel whether a wire was + or- when the sun was shining. Then compared the polarity to the connector. Each panel VOC was the same. Series connected 8 panels that have a VOC of 49.5V and then checked the VOC of the connected string, right at the 400V level.

Next, ran pv wire to control panel on array that contains IMO disconnect switch, breakers and surge protectors and checked open circuit voltage there. Then to the IMO disconnect switch inside the house at the inverters. Noting polarity at each step plus the pairing of wires is correct.

I prefer checking as I go along, eliminates problems such as open circuits, reversed polarity and determining if resistance is present with 2 strings to compare against each other.

 

[lns]

Good news, I found that I screwed up on one of the mc4 connectors I made which the metal contact was just short of reach of the panel's slightly different connector. Pulling about 190V into the battery . I also connected the 120V inverter and powered the booster pump. But there may be a problem grounding this 120 inverter as it has a live ground around 60V.

 

[timselectric]

Good news, I found that I screwed up on one of the mc4 connectors I made which the metal contact was just short of reach of the panel's slightly different connector. Pulling about 190V into the battery . I also connected the 120V inverter and powered the booster pump. But there may be a problem grounding this 120 inverter as it has a live ground around 60V.

It's not live.
It's floating at half potential voltage. Because it's not grounded.
Grounding/bonding it, pulls it to zero.

 

[Zwy]

Good news, I found that I screwed up on one of the mc4 connectors I made which the metal contact was just short of reach of the panel's slightly different connector. Pulling about 190V into the battery . I also connected the 120V inverter and powered the booster pump. But there may be a problem grounding this 120 inverter as it has a live ground around 60V.

What model inverter and where did you purchase it? How is bonding done on your system? Diagrams help, even if just a photo of a drawing on a napkin.

 

[lns]

What model inverter and where did you purchase it? How is bonding done on your system? Diagrams help, even if just a photo of a drawing on a napkin.

Current setup (NO AC input):
SS Growatt 5000 ES/US <=== 48V battery ===> WZRELB 3000W 120V inverter
^=== breaker box/panel <=== (L1/L2/G) 240V well pump
^=== PV array

Both the Growatt and WZRELB shows a ground voltage difference relative to L2/N. Growatt shows about 130V diff and WZRELB shows about 60V diff.

According to @FilterGuy 's stationary AC/DC system PDF and @timselectric , I should ignore that voltage difference and bond the L2/N to EGC and bond the 48V negative to EGC? If so, can I bond both the Growatt's and WZRELB's L2/N to the same EGC?
I bought an 8 ft grounding rod and 8awg EGC copper wire.

 

[timselectric]

I should ignore that voltage difference and bond the L2/N to EGC and bond the 48V negative to EGC?

No
Never said that at all.
DO NOT BOND A LIVE CONDUCTOR.
And I wouldn't ground the 48v system negative or positive, either.

 

[Zwy]

WZRELB 3000W 120V inverter probably needs the case grounded. These type of inverters are known for this.

Only bonding that should ever be done is neutral to ground and as there isn't a neutral for 240V system (non split phase), then you just have the EGC and tie it to ground.

The 8 foot ground rod and #8 wire should be tied to grounding busbar in breaker panel if this is a separate structure.

Make note of whether a diagram shows grounded or grounding. Grounded refers to neutral, grounding refers to ground/earthing for ground fault detection.

 

[Tecnodave]

Code specifically requires 6 ga solid copper grounding conductor at a minimum. This is large enough to bond a 200 amp panel.

 

[lns]

My apologies if I misunderstood how the Growatt single phase 240V output works.. I thought what we are using as the L2 wire is actually a neutral wire?

WZRELB 3000W 120V inverter probably needs the case grounded. These type of inverters are known for this.

The grounding terminal, the case, and the grounding nut test continuity... just like Growatt's grounding output terminal and its case.

Only bonding that should ever be done is neutral to ground and as there isn't a neutral for 240V system (non split phase), then you just have the EGC and tie it to ground.

The 8 foot ground rod and #8 wire should be tied to grounding busbar in breaker panel if this is a separate structure.

Make note of whether a diagram shows grounded or grounding. Grounded refers to neutral, grounding refers to ground/earthing for ground fault detection.

I will attempt to drive the rod into our rock-laden soil... thanks

 

[lns]

Code specifically requires 6 ga solid copper grounding conductor at a minimum. This is large enough to bond a 200 amp panel.

Does it specify a thinner ga if I'm just powering from a 10KW surge growatt and a 6KW surge wzrelb ?
Also wondering what they sell the 8awg copper at home improvement store for?

 

[timselectric]

Does it specify a thinner ga if I'm just powering from a 10KW surge growatt and a 6KW surge wzrelb ?
Also wondering what they sell the 8awg copper at home improvement store for?

From your house to the water shed, what wiring do you have?
I was under the impression that it was L1, L2, N, and G.
If this is correct , you don't need to drive a ground rod.
You already have an EGC from your service. While you are allowed to add an auxiliary ground rod, I wouldn't recommend it. (Creates other problems)

 

[Zwy]

From your house to the water shed, what wiring do you have?
I was under the impression that it was L1, L2, N, and G.
If this is correct , you don't need to drive a ground rod.
You already have an EGC from your service. While you are allowed to add an auxiliary ground rod, I wouldn't recommend it. (Creates other problems)

Separate structure with a panel requires a ground rod, NEC 250.32 Buildings or Structures Supplied by a Feeder(s) or Branch Circuit(s)

Now, if just the multi wire circuit was all there was, then a ground rod isn't needed. The panel classifies it differently. Ground can be the well if metal cased, a ground rod or ufer.

On my acreage, every structure has a panel and the required ground, some ufer, some ground rod along with an EGC from the main panel tied to the grounding busbar. No N-G bond in those panels and an EGC is run with the branch circuit to the structure from the main service entrance bonded panel at the pole. Also, for some reason the local inspector wants a bare #6 copper wire ran in the trench and tied to grounding busbar or bonded to ground, that I've never understood.

 

[Tecnodave]

From your house to the water shed, what wiring do you have?
I was under the impression that it was L1, L2, N, and G.
If this is correct , you don't need to drive a ground rod.
You already have an EGC from your service. While you are allowed to add an auxiliary ground rod, I wouldn't recommend it. (Creates other problems)

Absolutely incorrect.....

Current versions of the NEC do require a 4 wire service to an outbuilding as well as a separate ground rod at the outbuilding.

Correctly done the wiring to the outbuilding is done in PVC conduit (L1, L2, and N) along with the 6 ga solid bare copper wire buried directly in the earth alongside of the conduit.....NOT in the conduit.....Alternately it is permissible to have the current carrying conductors in direct burial cable but the bare conductor must be in direct contact with earth

Reasoning for this code update...........shunting a lightning strike at the outbuilding to ground and keeping it at a closer contact with the ground that the other conductors....

 

[timselectric]

1) I said nothing about a panel.
2) this is not an outbuilding.
There is rarely enough room to stand inside these things, without removing the roof.
3) this is an existing feeder/or branch circuit.
Which is why I asked the question about the wiring.
But to tell you the truth. Even if it was a separate "building" with a sub panel. I still wouldn't recommend a ground rod.

 

[timselectric]

Reasoning for this code update...........shunting a lightning strike at the outbuilding to ground and keeping it at a closer contact with the ground that the other conductors

The NEC is for personal safety.
Lightning protection is a whole different book.
Do you really think that a 6 gauge wire can harness a Lightning bolt?

 

[Tecnodave]

The NEC is for personal safety.
Lightning protection is a whole different book.
Do you really think that a 6 gauge wire can harness a Lightning bolt?

6 ga wire is what is required here, I do not know what will suffice for a major strike.

My Rohn communitations tower had welded joints after a major direct strike. The wi-fi repeater located there was toast as well as the anemometer at the tower top, battery, etc.

It now has a ground rod mounted upside down at the top isolated from the tower and bonded to ground with 350 MCM to a radial array of 8 ground rods. I‘ll let you know if that is enough

 

[timselectric]

6 ga wire is what is required here, I do not know what will suffice for a major strike.

My Rohn communitations tower had welded joints after a major direct strike. The wi-fi repeater located there was toast as well as the anemometer at the tower top, battery, etc.

It now has a ground rod mounted upside down at the top isolated from the tower and bonded to ground with 350 MCM to a radial array of 8 ground rods. I‘ll let you know if that is enough

350 definitely has a better chance. Lightning protection cables are usually a braided cable. (To quickly dissipate heat) Similar looking to some of the flexible bus bars that people show on here.
And yes, Lightning protection should be separated from everything else conductive. And be placed above and around what you are trying to protect.

 

[Zwy]

Absolutely incorrect.....

Current versions of the NEC do require a 4 wire service to an outbuilding as well as a separate ground rod at the outbuilding.

Correctly done the wiring to the outbuilding is done in PVC conduit (L1, L2, and N) along with the 6 ga solid bare copper wire buried directly in the earth alongside of the conduit.....NOT in the conduit.....Alternately it is permissible to have the current carrying conductors in direct burial cable but the bare conductor must be in direct contact with earth

Reasoning for this code update...........shunting a lightning strike at the outbuilding to ground and keeping it at a closer contact with the ground that the other conductors....

I always thought it was about lightning dissipation, but after watching many of Mike Holt's videos, I have to wonder if a strike hits the ground near that buried bare #6 wire; will current and high voltage be induced on that wire and a nice clean conductive path is present to carry the strike or induced current/voltage to a house or other structure? Requirement is attached to grounding busbar/ground rod (or substitute)

Maybe a few years down the road, all those bare #6 will be dug up outside a home and cut off.

 

[LydMekk]

Smaller cables (4mm, 6mm, 10mm etc.) connected to the panels/frame/rails etc. will NEVER fully divert a direct lightning strike. Also SPD modules will never fully STOP a lightning strike. If you are very very lucky they will sacrifice themselves and stop some of the damages.
A lightning spear on the roof (highest point around) with a big isolated cable going down and away from the house - into the ground will be my best bet regd. lightning - should not be connected to anything else.

The ground is only there for fault protection in your DEVICES inside your house.

 

[Zwy]

A lightning spear on the roof (highest point around) with a big isolated cable going down and away from the house - into the ground will be my best bet regd. lightning - should not be connected to anything else.

I know from personal experience these don't work well. My former house in town was a big 3 story house built in 1910. Built with electricity and indoor plumbing. It was also built with a big lightning rod setup that had huge cables that ran down 2 corners of the house to the ground. It's all still there, no one ever removed it, always put back in place when the house was roofed. The house sat up on a high spot and there were very few trees in the neighborhood that were taller than that hip roof peak with the 6 foot long rod sticking up there plus 2 others on the hip peaks.

One night a storm was coming in, the kids were fairly young yet and they had turned in for the evening as did the wife. I stayed up to watch the storm track on TV and internet. Around 11pm, it started getting pretty rough, rough enough I was getting a little concerned. The town we lived in had been hit over the last century by 4 tornadoes, 2 when I was a young kid and around the area, most farm places over the years seemed to get hit even if only once every 100 years,

I went upstairs to get the wife and children in the basement. Just as I reached down to wake my wife, lightning hit. The house went black and there was this burning smell of electrical fire. Nice. Where do you go in a storm when it's possible it's on fire somewhere in the walls with a possible tornado on the way?

Neighbor across the street saw it hit. Never hit that big rod in the sky, nope, it hit the service wires from the transformer to my house right in the center of the street. It then traveled to my service panel and thru every neutral in the house as it was searching for ground. It fried every light bulb in the house, any electrical device and burnt around outlets and switch boxes.

But that big rod in the sky was still standing there all proud because the house was still standing.

The ground is only there for fault protection in your DEVICES inside your house.

 

[timselectric]

When it comes to a direct lighting strike.
All that you can do is try and hope.

 

[Zwy]

When it comes to a direct lighting strike.
All that you can do is try and hope.

Mine wasn't direct in a sense, the strike followed that low resistance of the wire. Makes me wonder about that #6 copper laying in the ground. What is really something was a new service entrance properly bonded and with a brand new copper ground rod installed at the time just about 3 years prior. Why didn't the energy head to the ground rod instead of the neutral busbar?

Sometimes maybe the "rules" weren't always the best thing ever adopted. LOL

 

[timselectric]

The code updates every 3 years. Some things are added. Some things are modified. And some things are removed. We humans can't learn from our mistakes, until we make them. lol

 

[Zwy]

I told my wife last night I don't make mistakes, I make experimental excursions.

 

[msllarson2]

Hi, I'm new to the form... and honestly I could only spend 6+ hours trying to parse through the 900+ posts on this thread looking for an answer. All of the answers and replies get intermixed with "that will work" right after someone says that a different solution will not work. I understand some options cannot be made to work... but that doesn't mean no option will work.

To help summarize the past 900+ posts and narrow the answer for people who already have all or part of an SPF 5000 ES system:

• SPF 5000 ES from SS, or circuit board ground screw removal (no internal bonding between ground and neutral on AC input, which seems to be something someone can confirm with a DMM)
• 120VAC loads required, but not specific to any transformer(Growatt At5000, the solar edge transformer, or isolation transformer)

What are safe options for a system configuration to use the US grid as a backup and or input?
What are any associated caveats?