Polar Bear III 10 Degree Installation Manual
9910030 Rev B
12
Step 5: Electrical Grounding
Please consult with national and local building code(s) for complete grounding requirements for your
installation. The Polar Bear grounding method conforms to UL 2703 and is certified by ETL for use with
all photovoltaic modules listed under UL 1703. Installers can quickly and easily establish ETL-certified
electric bonds between all connected array components, including modules and mounting system
components, without the use of additional grounding devices, e.g. ground lugs and copper wire. At least
one ground lug must be used to ground all strings within a physical sub-array provided the fuse rating
for each string does not exceed 30 amps. Installers may opt to use multiple lugs per sub-array for
redundancy. When grounding devices are installed according with the approved methodology and
capacity below, the connections described above meet all the requirements outlined in NEC 690.43.
Additional information regarding UL 2703 and the specific modules included in PanelClaw’s ETL
classification can be found in the PanelClaw UL & ETL Overview (UL 2703) document (available at
www.panelclaw.com). For modules that are certified to UL 1703, please follow the instructions. For
uncertified and unapproved modules follow the grounding instructions below in Appendix C.
Grounding Instructions
PanelClaw components within the array are required to be electrically bonded to other DC grounding
paths via the use of either #8 or #6 AWG Cu bonding jumpers and a UL 467 listed Tyco solid wire
grounding assembly, part number 2106831, manufactured by Tyco Electronics Corporation.
To ground the array, first determine the groupings of strings whose power output wiring is grounded
together at an equipotential grounding conductor location. This could be all the strings within a physical
sub-array, or all the strings grouped by a single combiner box. Once the groupings of strings at
equipotential have been determined, a Tyco solid wire grounding assembly must be attached to one
Ballast Tray within each group of strings. PanelClaw’s Polar Bear Ballast Trays have a hole to which this
grounding device/lug can be attached (see
). In an array that requires multiple bonding jumpers
to satisfy the equipotential requirements, each bonding jumper should be located and installed on a
Support within the group of strings which will be grounded by that jumper. See Appendix B: UL 2703
Grounding Path for more information. Note: Every independent array section must include at least one
grounding device/lug.
To attach the Tyco grounding device/lug to the Ballast Tray, the mounting hex washer and threaded post
end should be installed to the specified hole in the ballast tray and torqued to 25 in-lbs (2.82 N-m).
Once the grounding device/lug has been attached to the ballast tray, a copper bonding jumper from an
acceptable DC grounded location outside of the array must be installed to the wire slot end and torqued
to 45 in-lb (5.08 N-m). For additional instruction regarding the installation of the Tyco solid wire
grounding assembly, please refer to the Tyco Electronics instructions sheet (document number 408-
10262) via their website