3.0
Installation and Commissioning
14
GenStar MPPT
15
If 156% of PV array Isc is greater than the maximum PV input breaker or fuse current rating, the
PV array breaker or fuse should be located at the output of the PV array combiner.
Load Output Overcurrent Protection Devices (OCPD) and Disconnect Switches
The output/load breaker or fuse rating must be no greater than 40 Amps.
The load fuse or breaker must be sized at a minimum of 125% of the maximum load output current. The
maximum load output current is the sum of the branch load circuits or the controller load output current
rating.
The load/output breaker or fused disconnect switch should be located near the load output terminals of the
controller.
The load output disconnect switch must have a minimum current rating greater than or equal to the fuse
current rating, but is not required to be higher than the load output current rating of the controller..
3.4 Wiring
WARNING: Fire Hazard
If multiple units are used in parallel for more charging current, the battery conductor
wiring must be sized for the total sum of all current ratings of the combined controllers.
CAUTION:
U.S. installed wiring must conform to all current U.S. NEC, ANSI/NFPA 70 requirements, and to
any local regulations. Non-U.S. installations must meet all national and local requirements of
the country of installation.
Before connecting any wires, read the instructions in Section 3.4, and lay out the lengths and
routes needed.
When wiring, secure and contain wire runs as required by code.
(3) ferrite chokes are included for individual installations around an RTS cable, PV (+) and (-) cables
(in one choke) and Ethernet cable. See Figures 3-3 and 3-4 for installation details conforming to FCC
Class B EMI requirements. Each core must be installed as close to the GenStar MPPT as possible.
Proper wire type and size is required for all installations.
Use only UL-listed Class B or Class C
stranded wire rated for 300 Volts and 75
º
C or higher. Copper wire
is recommended vs. aluminum
due to its ease of use, superior conductivity, strength and thermal expansion properties.
Battery and PV input terminal sizes:
8 - 1/0 AWG (10 - 50mm
2
)
Load terminal wire sizes:
14 - 6 AWG (2.5 - 16mm
2
)
Conductor ampacity (current carrying capacity)
must be
greater than the maximum current expected
in the power circuits.
!
Battery breakers or fuses
must be sized with a minimum of 125% of the continuous output current
rating of the solar controller. Recommended battery circuit fuse or breaker current ratings:
MODEL
Battery Circuit
Breaker/Fuse
Rating
GS-MPPT-60M-200V
75 or 80 Amps
GS-MPPT-80M-200V
100 Amps
GS-MPPT-100M-200V
125 Amps
Table 3-1. Battery Circuit Breaker/Fuse Current Ratings Meeting U.S. National Electrical Code
PV INPUT OVER-CURRENT PROTECTION DEVICE (OCPD) AND DISCONNECT SWITCH
RATINGS:
WARNING: Shock and Fire Hazards
The solar array open-circuit voltage (Voc) at the worst-case (coldest) module temperature must
not exceed the PV disconnect or overcurrent protection voltage ratings.
As defined in NEC Section 690.9, PV input
disconnect switches
must have a current rating great-
er than or equal to the maximum PV array current (Isc) multiplied 1.25. PV array Isc = # of strings
multiplied by the module Isc (STC) rating.
Note that individual PV string circuits do not require disconnects.
NEC Section 690.9 provides requirements for
overcurrent protection
. These requirements are
based on the maximum PV array current which equals 1.25 multiplied by array Isc, as defined in NEC
Section 690.9.
The PV input breaker or fuse rating should not be less than the next higher breaker rating above
156% of the PV array Isc. Maximum PV breaker or fuse ratings are :
MODEL
Maximum PV
Breaker or fuse
Rating
GS-MPPT-60M-200V
80 Amps
GS-MPPT-80M-200V
100 Amps
GS-MPPT-100M-200V
125 Amps
Table 3-2. PV Input Circuit Maximum Breaker or Fuse Current Ratings
String breakers or fuses are also required for parallel strings and are typically included with the PV
string combiner.
• There may be other code requirements specific to the installation of a particlular PV array.
As allowed for in NEC Section 690.9(A), PV input overcurrent protection is not required if both of the
following conditions are met:
1)
PV wire ampacity is sufficient to carry the maximum PV array current (ampacity is greater than
156% of PV array Isc)
2)
The maximum PV array current (125% of PV array Isc) is less than the maximum input Isc current
rating of the controller and PV disconnect rating.
