OutBack Power Installation Manual
Wiring 
900-0123-01-00 Rev C  29 
Wiring 
Table 2  Terminal Bus Bar (TBB) Wire Size and Torque Requirements 
Conductor Size  Torque Requirements 
AWG  mm²  In-lb  Nm 
#14 – #10  2.5 – 4  20  2.3 
#8  6 – 10  25  2.8 
#6– #3  16 – 25  35  4.0 
#2  35  40  4.5 
#1 – 1/0  50  50  5.7 
Grounding 
WARNING: Shock Hazard 
  The unit must be connected to a permanent wiring system that is grounded 
according to the IEC 60364 TN standard. 
  Make sure that no more than one bond is present in the AC system at any time. 
Some codes require the bond to be made at the main panel only.  
  For safety, the neutral and ground conductors should be mechanically bonded.  
The GS Load Center (GSLC) is equipped with a neutral-ground bond. If bonding is 
required to be in another location, the bond in the GSLC may need to be removed. 
  Some generators have a neutral-ground bond. When establishing a single bond 
elsewhere, it may be necessary to check for a generator bond. 
WARNING: Shock Hazard 
For all installations, the negative (–) battery conductor should be bonded to the 
grounding system at only one point. 
The GSLC comes equipped with a negative-
ground bond.
 This bond may need to be disconnected. If the OutBack GFDI is present, it 
can provide the bond. See page 30. 
IMPORTANT:  
Most OutBack products are not designed for use in a positive-grounded system. If it is 
necessary to build a positive-grounded system with OutBack products, contact OutBack 
Technical Support at 
+1.360.618.4363
 before proceeding. Additionally, consult the 
online forum at 
www.outbackpower.com/forum/
, where this subject has been 
discussed extensively. 
Figure 26  Grounding 
The GSLC’s grounding terminal bus bar ( TBB), which is 
bonded to the GSLC chassis, is located to the lower left of 
the main inverter disconnect. It accepts conductor sizes 
from 1/0 to #14 AWG (50 mm down to 2.5 mm). 
This TBB accepts ground connections from the Radian 
inverter, FLEXmax charge controllers, the OutBack GFDI, the 
Grounding Electrode Conductor (GEC) or external earth 
ground, and other equipment.  
See the Radian Series Inverter/Charger Installation Manual for 
recommendations on ground conductor sizing. Once the 
size is determined, see Table
 2 for required torque values. 
Ground TBB 










