DOES THIS CREATE A POTENTIAL HAZARD..?

[JRH]

I have a totally offgrid system not connected to the grid in anyway with everything bonded together and connected to an earthed electrode. The multi+ has no AC input connected from anything so it’s G/N Bond is always in effect.. the only power feeding the batteries is the solar from the multi…it is a 24 V system and it all works fine .

As I previously posted , about 2 weeks ago I had 4+ days with no sun at all and battery’s were getting low..So and hooked up a Victron IP 22 24v/16 amp portable charger I keep in my shed ,to a typical 20 amp outlet in the shed and I ran the two DC wires from the charger output out to the offgrid system a few feet outside the shed and hooked them to the bussbars to charge the battery’s that night…when the sun came up the SCC came on and both chargers worked together to fast charge the bank…It all did great …

but I got to thinking…

the sheds power that feeds the Batt charger is on a sub panel connected to the houses main system.

..the pv system is NOT connected to the shed or house system in any way, other than the pos and neg DC wires supplementally charging the batteries when needed..the charger is unplugged totally from the sheds AC system when not charging the batts.

the pv system has its own N/G connection ( in the multi) With its own dedicated electrode….the sheds sub panel is tied to the main house system with its own N/G and electrode up at the house…

Am I doing somthing risky having the Victron charger connected to the shed/ house system on its ground system while charging the pv offgrid system that is a separate and separately grounded system …

Again I say the only connection between the two system is the two DC charging wires connected to the batteries and only when I’m charging the battery bank .There is no overlap of AC power between the two systems ever...

I have never seen this question asked …..and I don’t know…thanks,
J.

 

[sunshine_eggo]

@timselectric will know for sure.

I expect no issue as the AC to DC side of the charger should be isolated. As long as you don't connect the charger housing or (-) to ground, I can't imagine it's an issue.

 

[timselectric]

1. There shouldn't be two separate grounding systems. They should be bonded together. There should only ever be one grounding system.
1a. If the PV panels have metal frames, they should be grounded. To prevent any shock Hazzard from touching them.
2. The DC side of the charger should be isolated from the AC side. But you should verify with a meter.
3.If isolated, there will be no issues with what you are doing.

 

[JRH]

@timselectric will know for sure.

I expect no issue as the AC to DC side of the charger should be isolated. As long as you don't connect the charger housing or (-) to ground, I can't imagine it's an issue.

1. There shouldn't be two separate grounding systems. They should be bonded together. There should only ever be one grounding system.
1a. If the PV panels have metal frames, they should be grounded. To prevent any shock Hazzard from touching them.
2. The DC side of the charger should be isolated from the AC side. But you should verify with a meter.
3.If isolated, there will be no issues with what you are doing.

Thanks Tim …yes , the array and offgrid system and all frames and everything are all installed and bonded and grounded back to one earthing point exactly as you described to me to do last year… they look right , meter correctly , no leakage or stray voltage anywhere.. it is all mounted in a enclosed trailer ..it’s a mobile system that is earth grounded.

the only reason there is two separate systems …it’s a neighbors house…. we are 100 ft apart and the house is 30 years old and the offgrid system is what I built this year next door to the house ..it’s like I’m running an extension cord over here to power the portable. battery charger when I need it..

I cannot say at this point the unit is isolated …i have a feeling it’s not. I’m still looking at the literature…it has a positive out put and three negative outputs. and a AC cord. See pics. That’s it..!

lastly, Mr Eggo suggested I not connect the (-) wire to ground …and I won’t , but, if it’s connected to the negative buss bar and feed the negative side of the battery’s and the batts are tied to the ground chassis buss barr and ultimately to the earth conductor for the whole system…isnt thst what he’s advising against.

@timselectric will know for sure.

I expect no issue as the AC to DC side of the charger should be isolated. As long as you don't connect the charger housing or (-) to ground, I can't imagine it's an issue.

as usual Thank you.
J.

 

[JRH]

Sorry I sorta got two reply’s mixed but I think you get the message…haaa
jim.

 

[JRH]

Thanks Tim …yes , the array and offgrid system and all frames and everything are all installed and bonded and grounded back to one earthing point exactly as you described to me to do last year… they look right , meter correctly , no leakage or stray voltage anywhere.. it is all mounted in a enclosed trailer ..it’s a mobile system that is earth grounded.

the only reason there is two separate systems …it’s a neighbors house…. we are 100 ft apart and the house is 30 years old and the offgrid system is what I built this year next door to the house ..it’s like I’m running an extension cord over here to power the portable. battery charger when I need it..

I cannot say at this point the unit is isolated …i have a feeling it’s not. I’m still looking at the literature…it has a positive out put and three negative outputs. and a AC cord. See pics. That’s it..!

lastly, Mr Eggo suggested I not connect the (-) wire to ground …and I won’t , but, if it’s connected to the negative buss bar and feed the negative side of the battery’s and the batts are tied to the ground chassis buss barr and ultimately to the earth conductor for the whole system…isnt thst what he’s advising against.

as usual Thank you.
J.

 

[Supervstech]

The issue is this.

While you are charging from the neighbors house (with his permission I hope!)
The case of the charger will have a different ground potential than your pv system...

And you can be electrocuted touching the charger, or in some circumstances just walking around it...

There is NOTHING like having an energized earth... every step shocking you...
I dont recommend it...

While you are charging, you should bond the grounds together between sources...

 

[JRH]

The issue is this.

While you are charging from the neighbors house (with his permission I hope!)
The case of the charger will have a different ground potential than your pv system...

And you can be electrocuted touching the charger, or in some circumstances just walking around it...

There is NOTHING like having an energized earth... every step shocking you...
I dont recommend it...

While you are charging, you should bond the grounds together between sources...

thank you…does that apply if isolated or non isolate or BOTH…I don’t like the word electrocuted.

 

[timselectric]

isnt thst what he’s advising against.

Yes
But if everything is properly bonded together. It probably wouldn't be a problem, anyway.
I would check everything with a meter, to be sure.
It's always better to find an issue with a meter, than a moist hand.

 

[sunshine_eggo]

Yes
But if everything is properly bonded together. It probably wouldn't be a problem, anyway.
I would check everything with a meter, to be sure.
It's always better to find an issue with a meter, than a moist hand.

 

[JRH]

Yes
But if everything is properly bonded together. It probably wouldn't be a problem, anyway.
I would check everything with a meter, to be sure.
It's always better to find an issue with a meter, than a moist hand.

Aww hell……meter test…..? I was gona use the good ole 9v battery tongue tap test… that always tells ya is there some juice there….but I will try using a meter..
you code guys take all the excitement outa stuff.
Thanks to all 3 of y’all for your time.
J.

 

[Supervstech]

Aww hell……meter test…..? I was gona use the good ole 9v battery tongue tap test… that always tells ya is there some juice there….but I will try using a meter..
you code guys take all the excitement outa stuff.
Thanks to all 3 of y’all for your time.
J.

… be sure to set the video camera to auto upload that tongue test…

 

[JRH]

… be sure to set the video camera to auto upload that tongue test…

Up here we say, “ watch theeeis”

 

[Zwy]

Yes
But if everything is properly bonded together. It probably wouldn't be a problem, anyway.
I would check everything with a meter, to be sure.
It's always better to find an issue with a meter,

than a moist hand.

You peeing into the wind again?

 

[JJJJ]

Smile and wait for the flash

 

[cs1234]

Up here we say, “ watch theeeis”

Hold my beer!

 

[sunshine_eggo]

Hold my beer!

"Ya'll come take a look at this 'fore I flush it!"