sizing surge suppressor for exist. switchboard

[jackman435]

We are doing a job that has a 1200a 3 ph 208y/120v MDP. Our job is to provide surge protection for this switchboard, and other downstream panels.The nameplate states " The short circuit rating of this switchboard section is = to the lowest rating of (1) any section electrically connected in series or (2) any installed panelboard having a marked short circuit rating." Does "connected in series" mean a panelboard that is being fed from this switchboard? Once the lowest rating has been determined, what are the next steps to getting the right surge suppressor. (The device must protect from the line side of the switchboard.

 

[ron]

I would guess they are talking about equipment within that enclosure, not downstream.

SPD's need to have an adequate short circuit rating, UL 149 3rd Edition listing, likely type 2 installation, surge current capacity per mode rating, MCOV rating per mode (based on nominal voltage), Nominal discharge current In, connection type (1Ph, 3Ph, 3W, 4W) and voltage rating.