STRCOM Fused String Combiners
Installation and Operation Manual
DOC-020040 rev 4.4
5
1 Introduction
The STRCOM String Combiner is a commercial, fused string combiner designed to be used for
combining multiple strings of PV modules for connection to an inverter or solar charge controller.
With this manual the STRCOM string combiner can be installed and operated safely. This
installation guide is used as reference for the commissioning and as a guideline on how to use the
string combiner most effectively.
In a large PV array, each string of PV modules must be fused before being paralleled and
connected to an inverter or charge controller. This string combiner is available in configurations
from 4 to 30 fuses. The combiner includes of choice of 600VDC rated fuses. Available fuses
sizes can be 8, 10, 12, 15 or 20A. Typically, the fuse size you chose is at least 1.56 x the short
circuit current rating of the PV string (or module used in the string) it protects. The fuse value
should not be more than the fuse rating listed on the module nameplate label or manual.
The STRCOM string combiner is available in either the standard version for use with negatively
grounded PV systems or an optional version for use with positively grounded systems (typically
used in conjunction with Sunpower Corp modules.) Note that neither the positive or negative
conductor is grounded in the string as this is typically done in the inverter for the system, however,
labeling is different in the negative and positive grounded string combiner versions.
The STRCOM fused string combiner is rated NEMA4 for outdoor use (NEMA4X Stainless Steel
also available as an option). It is designed and tested to be easy to mount and wire up. A flat tip
screwdriver is required to open the enclosure for typical rooftop applications and an optional lock
kit is available if access needs to be restricted farther.
Fig. 1 Fused String Combiner Application
Photovoltaic
Array
PVI 95KW
Inverter
Electrical
Grid
STRCOM
Fused String
Combiner(s)
