IQ 7 / IQ 7+ / IQ 7X / IQ 7A with EN4 Bulkhead Installation and Operation
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13
Branch Circuit Capacity
Plan your AC branch circuits to meet the following limits for maximum number of microinverters per
branch when protected with a 20 amp (maximum) over current protection device (OCPD).
Maximum* IQ 7 Micros
per AC branch circuit (240
VAC)
Maximum* IQ 7+ Micros
per AC branch circuit
(240 VAC)
Maximum* IQ 7X Micros
per AC branch circuit
(240 VAC)
Maximum* IQ 7A Micros
per AC branch circuit
(240 VAC)
16
13
12
11
Maximum* IQ 7 Micros
per AC branch circuit (208
VAC)
Maximum* IQ 7+ Micros
per AC branch circuit
(208 VAC)
Maximum* IQ 7X Micros
per AC branch circuit
(208 VAC)
Maximum* IQ 7A Micros
per AC branch circuit
(208 VAC)
13
11
10
11
*Limits may vary. Refer to local requirements to define the number of microinverters per branch in your area.
Utility Service Requirements
The Enphase IQ Series Micros work with single-phase service. Measure AC line voltages at the electrical
utility connection to confirm that it is within the ranges shown:
240 Volt AC, Single Phase
L1 to L2
211 to 264 VAC
L1, L2 to ground
106 to 132 VAC
208 Volt AC, Single Phase
L1 to L2
183 to 229 VAC
L1, L2 to ground
106 to 132 VAC
NOTE
:
All 208 VAC installations require that you use the Enphase IQ Envoy to
commission the Enphase Microinverters to propagate correct grid profile settings for
208 VAC trip points.
Wire Lengths and Voltage Rise
When planning the system, you must select the appropriate AC conductor size to minimize voltage rise.
Select the correct wire size based on the distance from the beginning of the microinverter AC branch
circuit to the breaker in the load center. Enphase recommends a voltage rise total of less than 2% for the
sections from the microinverter AC branch circuit to the breaker in the load center.
Enphase provides guidance about choosing wire size and maximum conductor lengths in the Voltage
Rise Technical Brief at
. Refer to this brief for voltage rise values in Enphase Q
Cables and on how to calculate voltage rise in other wire sections of the system.
Standard guidelines for voltage rise on feeder and AC branch circuit conductors might not be sufficient for
microinverter AC branch circuits that contain the maximum allowable microinverters. This is due to high
inherent voltage rise on the AC branch circuit.
Best practice
: Center-feed the branch circuit to minimize voltage rise in a fully-populated
branch. This practice greatly reduces the voltage rise as compared with an end-fed branch.
To center-feed a branch, divide the circuit into two sub-branch circuits protected by a single
OCPD. Using the Q Aggregator is a convenient way to do this.
