P A G E 1 4 O F 1 7
M I S S I ON S OL A R E NE R G Y L L C
ELECTRONIC
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C OP YR I GH T 2 0 2 0 M I S S IO N S OL A R E N ER GY L L C , AL L R I G H T S R ES E R V ED
REVISION: R2 RELEASE DATE: 9/25/2020
10.0
GROUNDING INSTRUCTIONS
A module with exposed conductive parts is considered to be in compliance with UL 61730 only when it is electrically
grounded in accordance with the instructions presented below and the requirements of the National Electric Code. To
reduce the possibility of electrical shock, ground the frame of the module or array before wiring the circuit using a
grounding method that meets NEC requirements for grounding solar electrical systems. In order to install on anodized
aluminum frames, Mission Solar Energy modules shall be grounded using grounding hardware that has been certified to
meet requirements for grounding systems in UL467, UL61730 or UL1741, which Mission Solar Energy recommends one
of the following methods of grounding the module frame. The attachment must be made in conformance with the
grounding device manufacturer’s instructions and be used with a racking system in compliance with UL Outline
(Standard) 2703 where this module has been evaluated with that racking system.
10.1
WEEB-UIR
The WEEB washer family of products can be used to bond anodized aluminum, galvanized steel, steel and other
electrically conductive metal structures. All installations shall be in accordance with NEC requirements in the USA and
with CSA C22.1 in Canada. The WEEB washers are for use with modules that have a maximum fuse rating of less than
25A. Use WEEB-UIR to bond solar modules to module mounting purlin and torque fasteners to 7 ft-lb / 9.5 N-m using
Penetrox-A on threads.
The following UL Recognized Bonding Washer, manufactured by BURNDY LLC (E351343), should be used to provide a
reliable grounding connection to the module frame.
MODULE
GROUNDING DEVICE
Manufacturer
Type
Torque rating
All
BURNDY LLC
WEEB-UIR grounding washer)
9.5 Nm
The BURNDY grounding washer should be used in combination with a flat washer and M5 size nut/bolt to bond the
module frame to the mounting rails/support (see figure 3).
Grounding should be achieved through securement to the array frame. The array frame shall be grounded in accordance
with NEC Article 250, and CSA C22.1, Safety Standard for Electrical Installations, Canadian Electrical Code, Part 1, for cUL
listed modules
Figure
3
