Generator Connections
An auto-start generator can be integrated with the Enphase Storage system
without the need for any external ATS.
NOTE:
This system is only compatible with permanently installed, hardwired
generators that are non-separately derived as per NEC 250.35(B).
Steps for connecting a generator are listed below:
A ) Wire the L1 and L2 AC wires from the generator into the generator lugs
on the IQ System Controller 2.
B ) Ensure that the ground terminal of the generator is connected to the
ground bar inside IQ System Controller 2. Size the generator’s equipment
grounding conductor as per NEC 250.122 and generator manufacturer’s
instructions.
C ) Connect the neutral wire from generator to an appropriately sized posi-
tion on the neutral bar inside IQ System Controller 2.
NOTE:
IQ System Controller 2 does not switch the neutral and the ground
from the generator. It only switches the feeders i.e., L1 and L2. Therefore,
the generator needs to be configured as a non-separately derived system.
D ) Buy and install an appropriately sized breaker for the generator on the
IQ System Controller 2’s busbar and connect the L1 and L2 generator cables
from IQ System Controller 2’s ATS board to this breaker.
NOTE:
The maximum allowed breaker size is 80A. Select an Eaton BR
breaker model that has the hole for the additional fastener as per NEC
480.36(D). Available models: BR220B, BR230B, BR240B, BR250B. Eaton
breaker BR260, BR280 already has the hole.
8
E ) Purchase and install a hold-down screw kit (SKU: EP200G-NA-HD-200A)
to secure the Generator breaker.
F ) Install a pair of generator CTs (CT-200-SPLIT) for L1 and L2 at the IQ
System Controller 2’s Generator input terminal for power monitoring when
the generator is running. Detailed CT wiring is described in step 9.
G ) Use Enphase Installer App mobile application to commission and pro-
gram IQ System Controller 2 to control the generator.
H ) For 2-wire autostart generators, wire the Generator I/O port in IQ System
Controller 2 to the 2-wire remote start terminals of the generator. Refer Step
7 for steps on how to secure the auxiliary contacts to IQ System Controller
2. Follow local code requirements for wire sizing.
I ) Autostart generators typically require a constant 120 Vac for battery
charger. This power can be drawn from the backup loads panel protected by
a breaker so that it is powered even during an outage.
J ) For permanently installed Propane/Natural gas generators, have a certi-
fied contractor install the gas line required to supply the unit.
K ) Some utility-sense based generators like the Generac Guardian come
with the capability to auto start generators when system goes off grid by
sensing the absence of the 240V utility power. For such utility-sense based
remote start generators, install the utility sensing generator start/stop
control circuit. Wire the primary of a 120V/12V power supply to the backup
loads panel. Connect the secondary to the Generator auxiliary contact relay
on the IQ System Controller 2. Wire the other end of the relay to the coil
of the Normally Close contactor. Connect the contactor to 240V from the
backup loads panel for utility sensing. Wire the other end of the contactor to
the Generator through a fuse.
Line diagram for 2-wire remote start generator connection
Line diagram for utility sense based remote start generator connection