Technical data

M250 Installation and Operation
 2013 Enphase Energy Inc. 141-00022 Rev 01
7
Planning for Microinverter Installation
Because the DC circuit is isolated and insulated from ground, the M250 does not require a GEC. The
M250 is compatible with most 60-cell PV modules (to 300W or higher) and installs quickly and easily. It
works with either three-phase 208 VAC or single-phase 240 VAC services. The M250 ships with
integrated DC and AC cables and connectors. The DC connectors attach to the PV module, while the AC
connector attaches directly to the Engage Cable. No additional cabling is needed.
The Engage Cable is available in two connector spacing options and two voltage types to meet varying
site requirements. For Engage Cable ordering information, see page 26.
Compatibility and Capacity
The Enphase M250 is compatible with 60-cell modules. The modules must use PV (photovoltaic) Wire.
For more information, see “Technical Data” on page 29. Refer to the http://www.enphase.com/support for
a list of approved PV racking systems. To ensure mechanical compatibility, be sure to order the correct
connector type for both microinverter and PV module from your distributor.
WARNING: The M250 can be paired only with a 60-cell PV module. The PV module DC
conductors must be labeled "PV Wire" or "PV Cable” to be compliant with NEC 690.35(D)
for Ungrounded PV Power Systems.
Electrical Compatibility
Model Number
Works with PV Module Type
PV Module Connector Type
M250-60-2LL-S22
60-cell PV module
MC-4 locking connector
Utility Service Requirements
The M250-60-2LL works with split phase 240 VAC service or with three phase 208 VAC service. Measure
AC line voltage at the electrical utility connection to confirm that it is within the ranges shown:
240 Volt AC, Split Phase
208 Volt AC, Three Phase
L1 to L2
211 to 264 VAC
L1 to L2 to L3
183 to 229 VAC
L1, L2 to neutral
106 to 132 VAC
L1, L2, L3 to neutral
106 to 132 VAC
Branch Circuit Capacity
Plan your AC branch circuits to meet the following limits for maximum number of M250s per branch when
protected with a 20-amp over-current protection device (OCPD).
Maximum number of M250s when protected with a 20 A OCPD
Service type
Max M250s per AC branch circuit
Split phase 240 VAC
16
Three phase 208 VAC
24
1
1
To avoid potential phase imbalance, minimize the number of unused connectors with three-phase systems. See
“Planning for Cable Lengths and Type” on page 27 for more information.