Single neutral/ground point

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Rhusch

Member
Location
Michigan
Occupation
Electrian
I have a customer he is sensitive to electricity (EMF), we are trying to have a single neutral/ground connection on a pretty complicated system.

Basic Overview:

200 amp main meter supplies a 200 amp SR automatic transfer switch - 3 Wire (Main Disconnect) currently neutral/ground bond- FEEDS MAIN HOUSE PANEL

100 amp meter (line side off main meter-3 wire) to a 100 amp SR automatic transfer switch - FEEDS HEAT PUMP - currently neutral/ground bond

20 KW whole generator -single feed going to 200 amp TS first then to 100 amp TS (four wire, no ground rod, no neutral/ground connection at generator)

6.1 KW stand alone solar array
with microinverters 300 feet behind the house, feeding on load side (Main Panel). Solar array -- Inventor panel (Isolated N/G), ground rod installed at solar array-- 4-wire to AC Disconnect (Grounded Only) --- generation Meter (neutral terminated) --- 4 wire to Main House Panel Load side.

(2) ground rods outside at house

Questions:

Does the 100 amp SR automatic Transfer Switch need a neutral/ground connection, because its a service disconnect? I would like the only Neutral/Ground connection to be at the 200 amp SR transfer switch.

The Solar Array Neutral and Ground is confusing me. They ran 4-wire from the AC Disconnect to the Solar Array system Inventor panel and wired it like a sub panel (Isolated N/G). The meter is a 3-wire termination design, Is that termination a neutral or ground? Can I run the neutral uninterpreted back to the main panel.

The Solar Array feeds into the House Panel, which the house panel is a 4-wire isolated system.

When all is done, the only N/G connection is at the 200 amp SR transfer switch. Grounds rod will terminate here also.
 

ActionDave

Chief Moderator
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Location
Durango, CO, 10 h 20 min from the winged horses.
Occupation
Licensed Electrician
If you've got two meters on one house you have a problem that needs corrected by getting rid of the second service and getting everything into one service disconnect. Once you do that your problem of two neutral to ground bonds will be solved.
 

Rhusch

Member
Location
Michigan
Occupation
Electrian
Understand that, but it’s a huge discount to have the geothermal system/heat pump on a separate meter. Any other suggestions.
 

StarCat

Industrial Engineering Tech
Location
Moab, UT USA
Occupation
Imdustrial Engineering Technician - HVACR Electrical and Mechanical Systems
If you are dealing with Electrosensitivity you need the best True Sine Wave inverter possible. Solar is very dirty by nature. While there is more to this, I have not had the time to investigate or colate the proper resources as of yet. I do have some archived shows dealing with the overview at home which can be gotten. Its advised you listen to Eric Dollard on the degradation of the power distribution system. Solid state devices that throw off dirty EMF can in many cases be dealt with using Faraday shielding methods when possible.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
If you've got two meters on one house you have a problem that needs corrected by getting rid of the second service and getting everything into one service disconnect. Once you do that your problem of two neutral to ground bonds will be solved.
I dont see that as a problem. Can you expand ?
(At one time that was common here.. one service (drop or lateral), two meters due to different billing rates.
 

ActionDave

Chief Moderator
Staff member
Location
Durango, CO, 10 h 20 min from the winged horses.
Occupation
Licensed Electrician
Understand that, but it’s a huge discount to have the geothermal system/heat pump on a separate meter. Any other suggestions.
Looks like I could be wrong about the two meters.

Electrically speaking you need the nuetral bonded to the ground at each meter for safety and as long as everything is wired correctly there won't be any EMF issues because the magnetic fields cancel out.
 

winnie

Senior Member
Location
Springfield, MA, USA
Occupation
Electric motor research
Can you draw out a diagram? Hard to understand where the ground/neutral bonds are on the link to the solar part of the system.

Is there any way that all _three_ meters (main, heat pump, generating) can be placed in a single meter bank with a single ground/neutral bond?

What is the topology of the grounding electrode system, and how are the grounding electrodes connected together? Is it possible that earth currents are being coupled into the wiring system?

-Jon
 

Rhusch

Member
Location
Michigan
Occupation
Electrian
2F93B689-1B2A-4E7B-B733-354F56E96924.jpeg
both transfer switches have have the neutral bonded.
I would like to only Bond the neutral at the 200 amp transfer switch and run my ground rods to the 200 DC. Everything else is 4-wire, separate neutral and ground connections.
 
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