What type of AC disconnect switch is required?

[Repman]

I'm preparing an electrical drawing to be submitted to my AWJ (Authority with Jurisdiction) which uses NEC 2014 and IRC 2018. (Important because NEC 2018 changed some requirements). My system is 36 panels producing 12.9kW Dc, and 2 Growatt 5000MTLP-US 5kW inverters, with integral Dc disconnects mounted within 10ft of the array to satisfy NEC2014. They produce 21A max continuous output at 240vac 1phase each, with an internal 26A overload protection device. My First question regards the AC disconnect: What's the requirements of it?

I would like to use a 30A non-fusible 2 pole disconnect on each, specifically the Square D QO200TRNM, spec sheet attached, because its small and inexpensive. But I'm not sure if it has to be pad lockable in the off position, or if it has to be fusible?

 

[Pete999]

I'm preparing an electrical drawing to be submitted to my AWJ (Authority with Jurisdiction) which uses NEC 2014 and IRC 2018. (Important because NEC 2018 changed some requirements). My system is 36 panels producing 12.9kW Dc, and 2 Growatt 5000MTLP-US 5kW inverters, with integral Dc disconnects mounted within 10ft of the array to satisfy NEC2014. They produce 21A max continuous output at 240vac 1phase each, with an internal 26A overload protection device. My First question regards the AC disconnect: What's the requirements of it?

I would like to use a 30A non-fusible 2 pole disconnect on each, specifically the Square D QO200TRNM, spec sheet attached, because its small and inexpensive. But I'm not sure if it has to be pad lockable in the off position, or if it has to be fusible?

Didn't they explain this on your Solar course Repman?

 

[Repman]

Pete999: No, I've never taken a course in Solar. Are you familiar with NEC2014?

 

[philip hill]

Didn't they explain this on your Solar course Repman?

understand the change over switch needs to be one that can be locked of to prevent power going back to the grid if solar or battery power is still to be used to protect tradesmen working on the lines the one above a normal changeover would do the job but doesnt comply

 

[Repman]

Phillip, That makes total sense, similar to the OSHA lockout tagout requirement for industrial applications in the US. Thank you for your response. I didn't realize this forum was primarily UK based until after I joined today, and I know electrical codes vary from country to country. Even within the US with AWJ applying different versions of the NEC code makes it less about what is logical, and more about what is the applicable code. I was hoping someone from the US familiar with NEC2014 as it's applied to solar could answer. Thanks again.

 

[Megawatt]

I'm preparing an electrical drawing to be submitted to my AWJ (Authority with Jurisdiction) which uses NEC 2014 and IRC 2018. (Important because NEC 2018 changed some requirements). My system is 36 panels producing 12.9kW Dc, and 2 Growatt 5000MTLP-US 5kW inverters, with integral Dc disconnects mounted within 10ft of the array to satisfy NEC2014. They produce 21A max continuous output at 240vac 1phase each, with an internal 26A overload protection device. My First question regards the AC disconnect: What's the requirements of it?

I would like to use a 30A non-fusible 2 pole disconnect on each, specifically the Square D QO200TRNM, spec sheet attached, because its small and inexpensive. But I'm not sure if it has to be pad lockable in the off position, or if it has to be fusible?

Yes the switch cans be non fusible and it has to be lockable which most of them are

 

[Pete999]

Pete999: No, I've never taken a course in Solar. Are you familiar with NEC2014?

I have a copy given to me by a friend, but not really conversant with it, not yet anyway
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Yes the switch cans be non fusible and it has to be lockable which most of them are

Every day a School day

 

[Repman]

Megawatt: Thank you for your response. I hope you are enjoying your retirement, I am, but was looking forward to doing more traveling. Because of Covid, I had to put that on hold and took on this solar project since I now have the time. I've had lots of exposure to industrial controls and machine guarding but none in the residential market. I'm in the permitting stage of the project and need to submit a one line diagram of the grid tied system to the AWJ. I think I can navigate the regulations with a little advise, and will hire a Master electrician to do the electrical installation. I noticed from your bio you've also been on the industrial side of the industry. Have you done many solar installations? Thanks again for your help.

 

[Megawatt]

Megawatt: Thank you for your response. I hope you are enjoying your retirement, I am, but was looking forward to doing more traveling. Because of Covid, I had to put that on hold and took on this solar project since I now have the time. I've had lots of exposure to industrial controls and machine guarding but none in the residential market. I'm in the permitting stage of the project and need to submit a one line diagram of the grid tied system to the AWJ. I think I can navigate the regulations with a little advise, and will hire a Master electrician to do the electrical installation. I noticed from your bio you've also been on the industrial side of the industry. Have you done many solar installations? Thanks again for your help.

No sorry but I was a controls electrician and always worked in chemical plant, paper plants, oil refineries etc. I’m just started doing domestic last year. I would love to start working on solar panels and doing the install. It’s interesting and that’s the way this world is heading