2 Introduction; Valid Model - Delta M42U Operation And Installation Manual

Introduction
2 Introduction
The M42U/M36U/M28U transformerless 3Ø PV inverters are designed to enable
the highest levels of efficiency and provide longest operating life by use of
state-of-the-art high frequency and low EMI switchmode technology.
They meet the design requirements of UL1741/SA, IEEE1547, IEEE1547.1,
IEEE1547.A and OSHA, and is suitable for indoor or outdoor use.
- This product utilizes a transformerless design, and is not provisioned with an
isolation transformer, and therefore has no galvanic isolation between the DC
and AC sides.
PV array circuits connected must be floating with respect to ground, i.e., must
not be referenced (bonded) to ground.
If grounded PV arrays are connected to the inverter, the inverter will not connect
to the grid and the error message INSULATION (E34) will appear on the display.
- It is prohibited to connect terminals L1, L2, or L3 to ground.
The inverter installation must be performed by an authorized electrician in accordance
with the the National Electrical Code® ANSI/NFPA 70 or the Canadian Electrical Code®
CSA C22.1 and/or other prevailing local codes, as well as OSHA requirements.

2.1 Valid Model

The user manual is valid for the following device types:
• M42U
_120
• M36U
_120
• M28U
_120
This user manual must be followed during installation, operation, and maintenance.
The overview of M42U/M36U/M28U Series each have three models as shown
in Figure 2-2. Delta reserves the right to make modifications to the content
and technical data in this user manual without prior notice.
• M42U • M42U
_121
• M36U • M36U
_121
• M28U • M28U
_121
14
_122
_122
_122