Wiring Connections; Grounding Requirements; Grounding The Pv Modules - Advanced Energy AE 3TL 600 Series Installation And Operation Manual

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• AC overcurrent protection for the utility interconnect (grid-tied) must be
provided by the installers as part of the inverter installation.
• Use only conductors with an insulation rating of 90°C (194°F) minimum
insulation rating.
• This equipment is intended to be installed as part of a permanently grounded
electrical system per the NEC or local standards.

WIRING CONNECTIONS

The inverter is connected to the utility grid at the AC terminals in the connection box.
These terminals require the use of a UL-approved compression terminal connector.
The AE 3TL inverter is configured for 480 VAC, three-phase output.
The inverter is connected to the DC photovoltaic array in the connection box, which
includes ten positive and negative terminals. The fuse size cannot exceed the current
carrying capabilities of the unit or the conductor.

Grounding Requirements

Determine the appropriate grounding method with the responsible authority having
jurisdiction.
• System grounding, if required by Section 250 of the National Electrical Code,
ANSI/NFPA 70, is the responsibility of the installer.
• The photovoltaic system grounding shall be installed per the requirements of
Section 690.41 through 690.47 of the National Electrical Code, ANSI/NFPA
70, and is the responsibility of the installer.

GROUNDING THE PV MODULES

• The PV frames require an equipment grounding conductor (EGC) per NEC
requirements.
• The inverter is a transformerless inverter. For this reason, it has no galvanic
isolation. Neither the (+) pole nor the (–) pole of the modules connected to the
inverter can be grounded. Only the array frame/racking and modules frame
must be grounded, or only the PV module frame and racking must be grounded.
• Insulation resistance detection (ground fault detection): Since the inverter is
connected to ungrounded PV arrays, it has an insulation resistance detection
circuit that measures the DC insulation resistance between the PV array inputs
and earth ground prior to starting.
• An Isolation Monitor Interrupter (IMI) is used to limit ground fault and back-
feed current to the array and the protective earth connection. This device limits
shock hazards by restricting the ability of the unit to connect to the grid when
the system exceeds the limits stated in UL1741. Additionally, the PV array
Isolation Monitor Interrupter monitors for ground fault current as required by
1‑8 Safety and Product Compliance Guidelines 570-1003552-05A