User Manual

Planning for a Three-Phase IQ Microinverter System – North America

AC Wire Management at the Junction Box

Wire management practices at the junction box are critical to the long-term reliability of any PV system.

Installers often install the roof-mounted junction box on the side of a rail.

For Junction Box Applications

Follow these recommendations to prevent moisture from accumulating in the junction box. This helps to

improve system reliability while ensuring that the wiring connections last for the life of the system.

• Make sure that cables enter the junction box from the side or from the bottom, never from the top

where water can enter the enclosure.

• Install cables with a drip loop. Secure the cable so that water drains away from the cable entry.

• Use properly sized strain reliefs and cord grips. Note that the Q Cable is elliptical, so the cable gland

securing the Q Cable must contain an inner gland designed for elliptical cable. These cable glands

are commonly available from electrical distributors or home improvement stores and are often

available under the following names:

– ½” Service Entrance (SE) watertight connectors

– UF cable gland (such as the Arlington UF50 Cable Connector)

• Properly tighten the strain reliefs to prevent cable movement and to prevent water ingress.

• Install the junction box to meet the manufacturer’s recommended mounting and orientation

requirements. Use NEMA 4 enclosures. (NEMA 3 enclosures have a limited mounting orientation

range and may not accommodate typical rooftop installations.)

• Consider drilling a small drain hole in the bottom, lowermost corners of the junction box, so that

moisture or condensate can drain out of the junction box.

Installing IQ Microinverters with Frame Mount Bracket

The Enphase Frame Mount attaches the Enphase Microinverters directly to module frames. This is an ideal

solution for rail-less racking solutions, whether residential or commercial. When using the Enphase Frame

Mount product, support the Q Cable to keep it off the roof by clipping it to the module frames using module

edge wire clips that work with PV cable and USE-2 cable.