February 25, 2020
Two shades, One wire
There are a few rules for doubling-up shades on one wire and one power supply output. The criteria depend on wire length vs gauge, as well as fabric size vs drive. See the chart below for all the specifics. By the way, a typical add-on load with 1 PDU would be one keypad.
This also allows you to exceed 10 shades per power panel, even if you aren’t constrained by wire. Just be sure to follow the square footage rules.
Fun fact: a HWQS or QSX processor consumes 8 PDUs, so those can be powered from a shade panel instead of a dedicated power supply, if design constraints require such.
Triathlon wired shade 10-output power panels work a little differently. They are a 12 VDC bus without any communication nor individual fuses. Since all 10 shades are actually bussed onto one power supply, the rules for doubling up are a little easier. To run 2 shades on one wire, subtract 3 AWG from the single-shade requirement. To run 3 shades, subtract 5 AWG. 4 shades, subtract 6 AWG.
For example, to power a bay of 3 shades that had only one wire run 100 ft away from the power supply, it would need to be “13 gauge or better” (12 AWG is widely available) wire.
Unlike the Sivoia QS power panel, the Triathlon power panel can never power more than 10 shades, regardless of fabric size or doubling-up. In other words, if you run thicker wire and double up Triathlons, you then need to leave some outputs blank to make up for it.