Needed is an official EG4 statement of RSD wiring requirements for this configuration:
1-18KPV with unmarked older comm board, used as master. Described only for single wiring in '18KPV External RSD Initiator Installation Instructions' 2023 v 1.0.0.
2-2nd 18KPV with 'I' comm board,used as slave. Described only for like version comm boards in 'RAPID SHUT DOWN WIRING INSTRUCTION GUIDE' 2024 V 1.0. section 3.2.
3-a pair of Tigo CCA modules, one per inverter. The solar strings of each inverter are designed to be independently TIGO safed for maintenance reasons.
4-Four paralleled EG4 Wall Mount All Weather batter packs. Shared and common bussed between the two inverters, and operating in closed-loop mode.
5-An external RSD switch for proper (all power sources) RSD shutdown. Ideally a single switch to help simplify and minimize the total number of disconnects in larger systems.
6-Maintenance of each inverter's built-in RSD push-buttons. These are labeled on the inverters now - so code inspection requires they either operate or are removed and covered permanently.
I am asking because some experimentation (based on the 18KPV manual, and the above references) and testing has yet to yield NEC compliant operation. The batteries always disconnect their breakers and lock-up their BMS panels-EG4 did well with the CAN bus work from both slave or master sourcing. But, only one or the other inverter recognizes the RSD active state (i.e., disconnects the solar panel RSD signaling, notes the RSD event in the alarm log). We have only tested with grid power on (just one scenario).
To meet approval at inspection this equipment must demonstrate RSD operation with NEC defined behavior. Permit applications expect the manufacturer's claim of RSD compliance to be documented as EG4 does ('EG4-18KPV-12LV-Certification' Certificate for Report: 230209047GZU-001 claims Photovoltaic Rapid Shutdown Systems (R2022) [CSA C22.2#330:2017 Ed.1] ). Unfortunately testing of our configuration fails to demonstrate the EG4 claim.
Can EG4 help with documentation, please?
Thank you,
