Why do we use a PV disconnect that breaks both the positive and negative side of a PV circuit?

[Quattrohead]

If you are getting shocks from your panels, they are knackered. Voltage is leaking from the electrical part to the frame.
Throw it away, it's done.

 

[tomy2]

Very true. In fact, an electrition that just memorizes rules is likely to get things wrong when they hit an unusual situation.

The other group that often does not understand the 'why' are code inspectors.....and that is really sad because they are in a position to enforce their ignorance.

speaking of pv shutoff switches, do you have a link to an UL listed one?

 

[MTM98290]

I have only one leg of my pv array running through a breaker. I have a Growatt with 120-250v mppt input. The array produces between 200-220v. The breaker is a Midnite 300v I believe. It is a double breaker that is hooked in series. This is the setup that was recommended when I purchased this equipment.

Should I add another to break the other leg? The way I read it I need to. I did get a tingle once when finalizing the setup of the array. The breaker was off but the panels were not fully covered when this happened.

My ground is held to the Ironridge rails with an Ironridge ground lug. It then travels through a conduit to the ac breaker panel busbar. The Growatt is attached to the AC breaker panel with a 3 wire conduit/Wire whip. The ground wire is attached to the ground lug in the panel then travels out and down to the 8 foot ground rod.

Other than breaking only 1 leg of the PV inputs, this is the correct way to hook up the ground?

I have 3 breakers in the 120V AC panel, one for a main, one for oulets and one for lighting. All are attached to hot, neutral and the ground bussbar.

If I have overlooked something please let me know the error of my setup. Thanks.

 

[timselectric]

A solar disconnect is supposed to break all ungrounded conductors, (Both positive and negative) with a single handle. Separate breakers with their own handle will not meet this requirement.
If I have read correctly, your grounding should be correct.

 

[MTM98290]

A solar disconnect is supposed to break all ungrounded conductors, (Both positive and negative) with a single handle. Separate breakers with their own handle will not meet this requirement.
If I have read correctly, your grounding should be correct.

Excellent. Thank you. I will add an identical breaker to the leg of PV input. Luckily I have extra slots I can break out of the Midnite babybox. Where do I get a pin to connect the 2 (actually 4) breakers together? Are they a home depot type item or are they more specific?

 

[Quattrohead]

You should be able to get the pin/lock tab thingy from the same place as the breakers.
If not, replace the breaker with a suitable 2 pole like this one Select your amps, it defaults to 20A