Hi guys.

I want some opinions and if possible the proof that someone is correct or wrong in the following comment.

On the Synsynk Face book page there is a big fight regarding the correct way to do this.

Some say you can only bond via a Relay and then some are saying that a relay isn't compliant and there should be a permanent bond between Earth and Neutral.

They say it is non compliant and that no COC can be given.

What do you guys say?

I will try and find the post and paste it here.

 

Some of the comments

"

Q. Why is an Earth neutral bond required A. It changes the output UPS from a class 2 to a class 1

Q. when ever Grid is present do you need to remove the bond A. Not straight away , Grid can be present but he inverter is still running it can take upto 2 mins to switch over the bond must remain until the inverter relay changes over.

Q. Can the relay operate as soon as the inverter changes over A. No you need s slight delay 500 ms to prevent upstream RCDs from tripping

Q. If the system is totally off grid can you add a permanent bond A. If no grid is connected then the answer is yes

Q. What is the rating of the earth bond contactor A. At least 50% greater than the fuse rating

Q. Do you need earth neural bond on Aux / Gen input I am not going to answer this I will leave for anyone’s comments

Remember Sunsynk is a true hybrid"

Some comment

" 

Okay.

Let’s put this Neutral earth bond nonsense to bed.

The manufacturer recommendations says a permanent earth/neutral bond may be used.

Lets look at the code sans 10142-1

7.12.3.1.2 In an installation that is supplied from a combination of transformers and alternative supplies located near to each other, the neutral points of each of these items SHALL be connected to a single earthed neutral bar (see P.1). This earthed neutral bar shall be the only point at which the neutral of the installation is earthed. Let’s just add that it also connected to an earth electrode AND the supply earth as per 6.111 and 7.12  SO A CONTACTOR IS NOT COMPLIANT!!

 

The contactor usage is for other countries and or if the installation is remotely installed from the supply.

 

So conclusion.

No relay/contactor, only permanent bond. This does not affect the warranty. This is safe for the installation. This is what the standards say"

Some comment

" 

 Name deleted is correct in saying local codes and laws supersedes any manufactures recommendations , that part is true .

However I don’t think he is interpreting the standards correctly around earth - neutral bonding .

The standards clearly state there can only be 1 point of bonding , not 2

11 minutes ago, Jacques Ester said:

7.12.3.1.2

Please also read and post the next section 7.12.3.1.3, as well as 6.12.4 that's referenced.

7.12.3.1.3

7.12.3.1.3 Where alternative supplies are installed remotely from the installation, or from one another, and where it is not possible to make use of a single neutral bar which is earthed, the neutral of each unit shall be earthed at the unit and these points shall be bonded to the consumer’s earth terminal (see 6.12.4). The supply from each unit which supplies the installation or part of the installation, shall be switched by means of a switch that breaks all live conductors operating substantially together (see annex S), to disconnect the earthed neutral point from the installation neutral when the alternative supply is not connected (see also 6.1.6).

 

6.12.4 Earthing of the neutral of combined sources When an installation that has a common neutral is supplied from a combination of transformers and generators located near one another, the neutral terminal of each of these items shall be connected to a single neutral bar. This neutral bar shall be the only point at which the neutral of the installation is connected to the consumer's earth terminal except as in the case in 7.12.3.1.3.

 

6.13 Bonding NOTE 1 The aim of bonding is to bring all the bonded parts to the same electrical potential. Amdt 4 NOTE 2 No external conductor is required if compliance with the requirements for continuity can be proved by the test in 8.7.2.

9 minutes ago, Jacques Ester said:

shall be switched by means of a switch that breaks all live conductors operating substantially together (see annex S), to disconnect the earthed neutral point

Am I reading this correctly? So if the inverter is installed in the garage (remotely), there must be a relay (switch) to disconnect the earth neutral point of the inverter?

2 hours ago, Jacques Ester said:

Q. Why is an Earth neutral bond required?

Field observation: In off-grid systems (TN-S/TT earthing) without N-E bonding, the output voltage across L, N, E terminals will be 220Vac L-N, 110Vac L-E and 110Vac N-E. However with N-E bonding, the output voltage across L,N,E terminals will be 220Vac L-N, 220Vac L-E and 0Vac N-E.

2 hours ago, Jacques Ester said:

Q. If the system is totally off grid can you add a permanent bond A. If no grid is connected then the answer is yes

Field observation: With a permanent N-E bond at the load output, the Deye/SunSynk inverter will REJECT a portable generator connected to the grid input even if the genset frequency is within allowable limits, is earthed at the same point as the inverter and has its own neutral earth bonding (for 220Vac L-N & L-E ).

Edited February 6, 20233 yr by Kilowatt Power

2 hours ago, Jacques Ester said:

Q. Do you need earth neural bond on Aux / Gen input?

I too would like an answer to this question. Getting weird issues with loads (DHW heat pump and 1.5kW submersible pump + soft starter) connected to the AUX/GEN port on an off-grid system. Used a 2CX 6 sq.mm Cu XLPE/SWA/PVC cable to connect the two then used the 150m deep well casing for TT earthing.

Edited February 6, 20233 yr by Kilowatt Power

I don't have all the answers. I am more familiar with Medium and High Voltage than Low voltage.

That is why I posted it here for comments.