Verification of Conformity — UL 1741 PCS CRD and UL 3141
Report Number: 80266993VOC | Project Number: 80266993 | Master Contract: 302773
Issued by: CSA Group, Suite 138 - 13888 Wireless Way, Richmond, BC, V6V 0A3
Date of tests: 2025-07-11 to 2025-08-14 | Signed: Peter Lim, Power and Energy | August 25, 2025
Summary
This report provides a detailed assessment of the compliance of the Lunar System with UL 1741-CRD PCS and UL 3141-Issue 1 standards, focusing on the Power Control System (PCS) integrated into these products.
Products Tested
Lunar ESS (LE-ESS-20KWH, LE-ESS-15KWH, L2-ESS-15KWH, L2-ESS-20KWH, L2-ESS-25KWH, L2-ESS-30KWH), Lunar Inverter (10-005025), Lunar MSAC (LE-MSAC-01), ConnectDER MSA (V-1-A-X).
Applicable Standards
UL 1741, 3rd Edition (September 28, 2021, Revision May 19, 2023) — PCS Certification Requirement Decision Date: 2023-04-08, Revised: 2024-01-18
UL 3141, Issue Number 1 (January 11, 2024)
System Description
The Lunar Battery system (Inverter + Battery Block) combined with the Lunar MSAC and ConnectDER MSA is certified for UL 1741 PCS CRD and UL 3141 Issue 1, with the PCS controller integrated within the Lunar Inverter. Open-loop response time is less than 2 seconds. Maximum PCS Controlled Current: 200A (Bridge & Main Panel).
PCS settings are not mandatory for installation, but can be configured to facilitate NEC compliance and/or utility interconnection requirements.
PCS Functionalities
Power Import Limiting (PIL)
Power Export Limiting (PEL)
Busbar Overload Control (BBOC)
Feeder Conductor Overload Control (FCOC)
ESS Operating Modes — Response Times
PCS Mode | Description | Max OLRT | Avg OLRT |
Unrestricted Mode | Battery charges from PV and grid; battery and PV can export to grid | 61.535 ms | 5.69 ms |
Export Only Mode | Battery charges from PV only; battery and PV can export to grid | 753.598 ms | 11.19 ms |
Import Only Mode | Battery charges from PV and grid; only PV can export to grid | 309.262 ms | 10.01 ms |
No Exchange Mode | Battery charges from PV only; only PV can export to grid | 226.679 ms | 12.08 ms |
Test Results Summary
UL 1741 CRD | UL 3141 | Test | Result |
203.5 | 8.3 | Step Change in Load Test | PASS |
203.6 | 8.4 | Step Change in Generation Test | PASS |
204.1.1 | 8.6.2 | Export Limiting from all sources to EPS | PASS |
204.1.1 | 8.6.2 | Import Limiting from area EPS | PASS |
204.4 | 8.6.5 | Export Limiting from ESS | PASS |
204.5 | 8.6.6 | Import Limiting to ESS | PASS |
205.5 | 8.7 | Startup/Self check Abnormal Tests | PASS |
205.7 | 8.7 | Operating Abnormal Tests | PASS |
Conclusion
The Lunar PCS system has demonstrated full compliance with UL 1741 PCS CRD and UL 3141 Issue 1, reflecting its capability to perform critical power control functions reliably and safely.
Important Note: The Lunar PCS is supplemental protection. All PCS-controlled busbars or conductors must also be protected with suitably rated overcurrent devices. PCS settings may be used for NEC Article 690, 705, 706, 750, 220, 710 calculations as supplemental protection, but overcurrent protective devices remain essential per NFPA 70.
Source document: https://documents.lunarenergy.com/verification-of-conformity