Installing before controller

Started by jjjjj, June 06, 2022, 06:21:08 PM

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I am sure this has been answered, however cannot find it at this time.

I am looking at installing the SBD before the controller inside the house. My question is fairly basic I hope. Do I attach the two leads to the solar input lines prior to the controller? My next question is where to I apply the ground? I will have grid feed into my inverter charger.

Thank you


Yes, an SPD lightning arrestor  would connect to the positive and negative PV lines and the GND should connect to the controller's chassis or case GND.   Then the controller and equipment next  to it (like the inverter) get grounded wherever  the ground comes from.

The SPD helps keep the high voltage from the lightning from arcing over the electronics internal insulation to the chassis/case ground.

Usually everything is grounded to the main electrical panel if the grid is the main power source so your situation may be different.

K7IQ 🌛  He/She/Me


I will be using the Midnight Classic. It will be connected to a Victron Multiplus (grounded by ac grid input)  by a bus bar.  Does the Classic have a ground input? My goal here is to protect it. Also a concern here is that it's output would be directly connected to a bus bar (not the inverter) which is directly connected to the batteries.

According to an electrical engineer the Vicron case is grounded by virtue of the AC input. In this case, could I create a junction box to enable to surge output to go to the input ac ground wire?

On the other hand, would it be beneficial to run a separate #6 wire to the water line in the basement since this is where the ground is currently bonded?

Thanks again


Yes, the Classic has a ground terminal.

In the Classic, one of the insulation limits is the thermal insulator between the power FETs and the chassis.

The Victron is more than likely, similar in that regard.

Not sure about the water line but that is one way people ground things.  I am not sure exactly what the best place to ground this would be.
Others here may have suggestions.  Kind of hard to "test" though, isn't it ?  :)

K7IQ 🌛  He/She/Me


Agreed, testing would be a challenge.

I had an opportunity to look at the manual. Am I correct that the SPD is in parallel to the PV input circuit? I am not an electrician or engineer but it looks that way to me.

Having said that, I am wondering how this unit provides its protection. If it was like a breaker I would understand. However, what keeps overflow current from flowing through the parallel PV input if I am reading this properly.

Sorry if this is uninformed. I am new to this topic.  On the other hand, does this act as a shunt to ground if input current exceeds a certain value?