Powerwall 3 Wall Bracket Anchoring Details for Stacked Configurations

A7 - Required Wood Stud Quantity for Load Distribution

It is recommended that the below framing limitations, when exceeded, are reviewed by a structural designer or other qualified person acceptable to the Authority Having Jurisdiction (AHJ). This table has used ICC code prescribed loading and ASCE 7 calculations to approximate suitable stud height, size, and spacing limitations for common site criteria and construction techniques. The number of studs listed in the table for the associated stacking arrangement shall be attached to the wall with one of the following details. The bracket, if compatible with the wall framing, is a minimum requirement. If the stud spacing is not compatible, the channel strut detail shall be used. See the General Anchoring Notes section for more information. This table is intended to be used with the following details:
Table 1. Recommended Quantity of Wood Studs Required for Powerwall 3 and Expansion Unit(s) Stacking 3
Total Units Seismic Design Category (SDC)2 Size and Maximum Spacing (in)
SPF 2 x 4 at 24" o.c.2 SPF 2 x 4 at 16" o.c.2 SPF 2 x 6 at 24" o.c.2 SPF 2 x 6 at 16" o.c.2
Maximum Height of Stud top of sill plate to bottom of double top plate (ft)
8 9 10 8 9 10 8 9 10 8 9 10
Maximum Wind Speed Exp C or Less (mph)1
115 100 - 140 125 110 155 140 125 180 170 155
Powerwall 3 with One Expansion or Two Expansions 2 A, B 2 2 - 2 2 2 2 2 2 2 2 2
2 C 2 2 - 2 2 2 2 2 2 2 2 2
2 D 2 2 - 2 2 3 2 2 2 2 2 2
2 E2 3 3 - 3 3 3 2 2 2 2 2 2
Powerwall 3 with Two Expansions or Three Expansions 3 A, B 2 2 - 2 2 2 2 2 2 2 2 2
3 C 2 2 - 2 2 2 2 2 2 2 2 2
3 D - - - 3 3 - 2 2 2 2 2 2
3 E2 - - - 4 - - 3 3 3 3 3 3
Powerwall 3 with Three Expansions 4 A, B 2 2 - 2 2 2 2 2 2 2 2 2
4 C 2 2 - 2 2 2 2 2 2 2 2 2
4 D - - - - - - 3 3 3 3 3 3
4 E2 - - - - - - 4 4 4 4 4 4

Notes:

  1. Wind Exposure D is outside the scope of this table.
  2. Douglas Fir-Larch (DF-L) Stud Grade sawn lumber was used for SDC E.
  3. If the number of studs listed for a specific combination is not available, that specific combination of stacked units and studs is not recommended.

A8 - Acceptable Arrangements for Stacking Powerwall 3 and Expansion Units

Confirm wall framing at site and align with other guidelines provided in this manual. The studs must be full height (see General Anchoring Notes for note about not mounting to half walls or above / below windows) and part of the existing permitted building structure.

Example: (2) 2-stack SDC D, 2x4 at 16" oc 9 ft height, wind 125 mph

Per the Recommended Quantity of Wood Studs table, a total of (4) studs are required for this configuration, (2) stacks of (2) units installed to (2) studs each.

Example: 3-stack SDC E, 2x6 at 16" oc 10 ft height, wind 155 mph; (3) studs are required for this configuration.

Example: 4-stack SDC C, 2x6 at 24" oc 9 ft height, wind 135 mph; (2) studs are required for this configuration per the 140 mph column.

Example: 4-stack SDC E, 2x6 at 16" oc 8 ft height, wind 180 mph; (4) studs are required for this configuration.

A9 - Mounting Units to Avoid Sharing Studs or Struts

Do not share studs or struts when supporting multiple stacks of units. Each stack shall be mounted to its own pieces of strut to its required stud quantity. This requirement applies to both ground-mounted and wall-mounted units.

A10 - Mounting Units to Avoid Sharing Studs or Struts

Do not mount a unit above another unit; this is not allowable per the Powerwall 3 clearance requirements, and it could result in overloading the shared studs.

Considerations for Mounting Units on Both Sides of Wall

Example: This configuration has two stacks of (2) units, but because they share studs it is equivalent to having (4) stacked units. Design this configuration following the same guidance as for a stack of (4). Careful consideration shall be taken for wood screw interferences when installing from opposite sides of a stud.