I am planning a DIY installation. While I will be getting an electrician involved, I want to understand things and have been reading the manual for the SMA 3000TL transformerless inverted. I will be installing the array on a metal roof atop a wooden shed if that is relevant. I am planning to use Canadian Solar 260W modules on an iron ridge rack system that will be lagged through the metal roof into the wooden rafters of the shed. While I am a newbee I hope it is OK to post here as this is a technical question.
I don't understand the meaning of the following paragraph in the SMA Installation manual:
6.4.2 Conditions for the DC Connection
The inverter is transformerless and has no galvanic isolation. Therefore, the inverter may only be
operated with ungrounded PV arrays. Furthermore, the PV array must be installed in accordance with
the National Electrical Code®, Article 690.35 "Ungrounded Photovoltaic Power Systems" and the
locally valid regulations for ungrounded PV arrays. Additionally, the PV array (PV modules and
cabling) must have protective insulation and the PV modules used must be suitable for use with this
inverter.
What is an "ungrounded PV array"?
I have an existing professionally installed 4.6 kW system on a totally similar building with an SMA 4000TL inverter. It appears that there are grounding wires that connect the Iron Ridge rails and then go into a grounding rod in the earth.
Does anyone have a link to a schematic wiring diagram for an array that show the grounding connections?
Also, a separate question not related question: in connecting 240V AC to the panel do I need to use a ground fault type breaker?
Thanks for any inputs and comments.
I don't understand the meaning of the following paragraph in the SMA Installation manual:
6.4.2 Conditions for the DC Connection
The inverter is transformerless and has no galvanic isolation. Therefore, the inverter may only be
operated with ungrounded PV arrays. Furthermore, the PV array must be installed in accordance with
the National Electrical Code®, Article 690.35 "Ungrounded Photovoltaic Power Systems" and the
locally valid regulations for ungrounded PV arrays. Additionally, the PV array (PV modules and
cabling) must have protective insulation and the PV modules used must be suitable for use with this
inverter.
What is an "ungrounded PV array"?
I have an existing professionally installed 4.6 kW system on a totally similar building with an SMA 4000TL inverter. It appears that there are grounding wires that connect the Iron Ridge rails and then go into a grounding rod in the earth.
Does anyone have a link to a schematic wiring diagram for an array that show the grounding connections?
Also, a separate question not related question: in connecting 240V AC to the panel do I need to use a ground fault type breaker?
Thanks for any inputs and comments.
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