Wiring spd in combiner box

[cho]

I notice that in some combiner boxs surge protection device is wired positive to negative and negative to positive. Why?

What is correct positive to positive or positive to negative? And is that important?

 

[mopat]

Consider the PV the current source not the inverter. Yes polarity is important because SPD's may arc over and not offer protection.

 

[cho]

Thank you Mopat for correct wiring DC breakers document.
That was new informations for me.

But I still don't understand how to properly connect SPD in combiner box.
Does I need to connect positive (+) to negative (-) / negative (-) to positive (+)
or positive (+) to positive (+) and negative (-) to negative (-)


in this diagram SPD is wired negative to positive / positive to negative

 

[iamrich]

Mine is pos to pos, neg to neg, and ground to ground. What models are you using?

 

[mopat]

positive (+) to positive (+) and negative (-) to negative (-)

PV positive to SPD/(breaker) positive, negative to negative.

Attached may further clarify.

 

[cho]

PV positive to SPD/(breaker) positive, negative to negative.

Thank you Mopat for your advice and attachments

What models are you using?

Tanfon HT series pv array combiner box

 

[cho]

On this picture what does it mean "only in theoretical example"
Is that mean that one pole circuit breaker goes only on positive wire or can be put also on negative wire?
Like you can see in my combiner box circuit breaker is on negative wire. Is that correct?

 

[burgerking]

Thank you Mopat for correct wiring DC breakers document.
That was new informations for me.

But I still don't understand how to properly connect SPD in combiner box.
Does I need to connect positive (+) to negative (-) / negative (-) to positive (+)
or positive (+) to positive (+) and negative (-) to negative (-)

View attachment 72720
in this diagram SPD is wired negative to positive / positive to negative

?????

Isn't this wiring wrong?

I mean after a surge, there is a chance that the SPD will blow the fuse but not tripping the left-most MCB, the load is no longer protected by the SPD.