Solar shut off

[GotSmart]

I have not kept up with the industry, and would like to put a cut off for my panels right before the controller. 

I will have 1,000 w on the roof going to a tracer charge controller. I am clumsy enough so I don’t want to take a chance on short circuiting every thing. Most shut off switches seem to be set up for the positive side of a battery.  Large connections on a 10 gauge wire.  With solar you are supposed to open the ground first?  This has given me a headache   ?

[sternwake]

I believe there is potential danger to panel diodes when disconnecting from controller, in full sun.
But perhaps unfounded.

Me thinks it is wise to avoid such a scenario, when possible.
When I have to disconnect in full sun, out comes the cardboard, but a residential system nixes that.

Never heard about ground disconnect first, does not mean its not right though.

A big Ole On OFF switch is nice, unless trying to incorporate circuit protection with a non self resetting circuit breaker.

push button break, swing lever reconnect:


Thermal Circuit breakers can waste a Watt or 3 as heat.

[rvpopeye]

I have pulled the array positive wire from the controller after dark ( basically a spst switch )
for many years with no noticeable ill affect.

Ditto on not hearing anything about the negative let alone the sequence.
And I have heard the cover panels or wait till controller is shut down after dark and do that.

Just don't disconnect the battery first skuh kuh kuh kuh kuh

[justjim]

I generally suggest a surface mount circuit breaker on the positive line right before the controller in my builds. Normally for 10 gauge I go for 30-40 amp depending on the output of the combined panel imp. Four $50 250 watt panels from Santan wired in parallel could possibly exceed 30 amps so I suggest 40a.

Actually unless there was shading issue I would suggest running the panels 2 sets of 2 to drop the current. Only Jbox brand is producing 50 amp branch connectors. Unfortunately since the T Tocas brand was bought out, their circuit breakers voltage ratings were dropped from 72 volts back down to the standard 48 volts. Now the only higher voltage options is Midnite breakers in a baby box.

[tx2sturgis]

This might work, it's rated at 64 amps (2*32 amps)...

https://www.aimscorp.net/aims-power-sola...witch.html

It's designed to suppress the arc that can occur under full solar output conditions and high power levels.

I would assume that some kind of insulator is moved into position as the contacts are drawn apart. But that's just a guess.

[GotSmart]

After looking at the current solutions, I have decided to go old school. A couple of house light switches plainly marked. That will clear up any confusion about the power in lines. I would much rather spend about $10 than $150.  



The 40 amp details

[rvpopeye]

Close enough for a barn......

[GotSmart]

I generally suggest a surface mount circuit breaker on the positive line right before the controller in my builds.  Normally for 10 gauge I go for 30-40 amp depending on the output of the combined panel imp. Four $50 250 watt panels from Santan wired in parallel could possibly exceed 30 amps so I suggest 40a.

Actually unless there was shading issue I would suggest running the panels 2 sets of 2 to drop the current. Only Jbox brand is producing 50 amp branch connectors. Unfortunately since the T Tocas brand was bought out, their circuit breakers voltage ratings were dropped from 72 volts back down to the standard 48 volts. Now the only higher voltage options is Midnite breakers in a baby box.

There is the 1,000 w and unknown volts in that wire. 40 amp rating is easy. Do I need to worry about voltage?  

[justjim]

Open circuit voltage on each of those 250w panels is 37.6v and working is only 30.3v. I would not run all four in series but 2 and 2 would be fine.

All four in parallel is 33 amps and 30.3 volts.

2 and 2 is 17 amps and 61 volts

All four in series is 8.27 amps at 122 volts. Unfortunately the Voc at this point exceeds the controller without even considering cold temps or cloud effects that can push it even higher.

[GotSmart]

Open circuit voltage on each of those 250w panels is 37.6v and working is only 30.3v. I would not run all four in series but 2 and 2 would be fine.

All four in parallel is 33 amps and 30.3 volts.

2 and 2 is 17 amps and 61 volts

All four in series is 8.27 amps at 122 volts. Unfortunately the Voc at this point exceeds the controller without even considering cold temps or cloud effects that can push it even higher.

I had planned for everything being parallel. 

On Amazon they have a WOHHOM brand WA40A breaker. One on each line in to give extra safety.  $14 each. They are rated for 12 volts. 

 I do have one of the battery type switches available.