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You can sometimes avoid skipping Engage Cable connectors with the use of Engage
Couplers. The Engage Coupler can be used to connect two Engage Cables or to connect Engage
Cable to field cable. There are many possible scenarios for each type of connection, but they
generally fall into four categories:
o
Engage Cable to Engage Cable:
1. Make use of leftover lengths of Engage Cable
2. Transition between portrait and landscape Engage Cable
o
Engage Cable to Field Cable (#12 TC-ER):
3. Transition between sub-arrays on the same circuit
4. Create wiring extensions for Engage Cable
NOTE: Engage Coupler only supports #12 TC-ER, which may not be sufficient for
homerun wiring. Enphase Energy recommends maintaining less than 2% voltage drop
across all wiring.
In situations where you cannot use an Engage Coupler, you can use an electrical junction box to
transition between cable types.
Additional lengths of cable must be taken into account when calculating total VRise. Refer to the
following documents to maintain AC VRise at less than 2%:
o
Applications of the Engage Coupler
o
Circuit Calculations for the M250 Microinverter
o
Calculating AC Line Voltage Drop for M250 Microinverters with Engage Cables
Additional length required to reach from one row of PV modules to the next. If the PV
modules are laid out in multiple rows, the distance from one row to the next often requires
additional cabling length.
Bend radius. When planning cabling turns or loops, you must account for a minimum bend
radius of 4.75 inches (12 cm).
Multiple sub-arrays. Often, the AC branch circuit is composed of several smaller sub-arrays
across more than one roof plane. In this case, cut the cable to service each smaller array, and the
sub-arrays are connected together using appropriately rated lengths of conduit. The transition
from cable to conduit is accomplished using an outdoor-rated AC junction box, as required by the
NEC and local code. Unused connectors must be covered with Enphase sealing caps.
Mixture of PV modules in both portrait and landscape orientation. When PV modules are
installed in mixed orientation (both portrait and landscape orientation), there are three choices for
cabling:
1. Cabling with 1.025 meter spacing between connectors results in cleanest install for the
PV modules in portrait orientation. For PV modules placed in landscape orientation, plan
for an unused connector between each PV module to accommodate the additional
distance. Unused connectors must be covered with Enphase watertight sealing caps.
2. Cabling with 1.7 meter spacing between connectors results in cleanest install for PV
modules in landscape orientation, but requires that any additional cable length between
PV modules in portrait orientation be coiled and dressed so that the cable does not
contact the roof. Again, unused connectors must be covered with Enphase sealing caps.
3. Another solution when PV modules are installed in mixed orientation is to transition
between 1.025 and 1.7 meter spacing cable options using the Engage Coupler or an
outdoor-rated junction box. This junction box can be installed to the PV racking. Refer to
http://enphase.com/products/engage-coupler/
28
2013 Enphase Energy Inc.
M250 Installation and Operation
for information on the Engage Coupler.
141-00022 Rev 01
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