Preparing for UL 3141 and ULC/ORD-C3141 Certification

28 Oct 2026

A Manufacturer’s Guide to Demonstrating ESS Reliability, Performance, and Safety

As the distributed energy resources (DER) market continues to expand, the industry is demanding greater accountability and a measurable way to demonstrate the reliability, performance, and safety of energy management systems.

UL 3141 and ULC/ORD-C3141 are safety standards developed to evaluate the performance, functionality, and safety of power control systems (PCS) used in DER applications. These systems manage and regulate energy flow between the utility grid, energy storage systems, renewable energy sources, and connected loads, helping to ensure safe and efficient power distribution.

With the withdrawal of UL 1741 PCS testing guidelines, UL 3141 and ULC/ORD-C3141 have become the primary standards for evaluating PCS solutions.

Understanding UL 3141 and ULC/ORD-C3141 Testing Requirements

The objective of UL 3141 and ULC/ORD-C3141 evaluation and testing is to verify that PCS response times remain within specified limits during parameter variations while maintaining safe system operation.

A PCS regulates system current and power import and export levels, with these limits often established through commands issued by utilities or other authorized third parties. To support compliance with these requirements, renewable energy resources, energy storage systems (ESS), measurement devices, and sensors may be integrated into the equipment or deployed externally within the system for monitoring and control purposes.

According to UL 3141 and ULC/ORD-C3141, a PCS may include:

• Generation devices, such as inverters and engine generators
• Energy storage systems (ESS)
• Electrical loads
• Load control applications, including EV charging power and load management systems

A PCS may be incorporated into another certified product or supplied as a standalone device. As a result, the certification pathway for UL 3141 and ULC/ORD-C3141 can vary depending on the specific system architecture and application. The applicable end-product standard must first be identified, as the PCS is evaluated in conjunction with the end-use product or system.

UL 3141 and ULC/ORD-C3141 RFQ Checklist

To help streamline the quotation and certification process, manufacturers should be prepared to provide the following information:

Equipment and System Information

• Confirmation that PCS controller is implemented in another certified equipment or not (standalone)
• Confirmation that all equipment and components are certified and rated for the intended operational voltage and current levels
• A suitable installation guide specific to the intended end-use application
• All the possible configurations are included in the installation manual
• Models of all measurement devices, power conversion devices, ESS, PCS-controlled loads, EVSEs used in system are identified in the manual
• Safety analysis of the system and system components for each of the configuration is required to determine the applicability of the Functional Safety

PCS Function Identification

Confirm for which PCS function, the PCS is designed for:

• Power export limit (PEL) including zero export mode
• Power import limit (PIL) including zero import mode
• Net energy metering (NEM)
• Busbar overload control (BBOC)
• Feeder overload control (FCOC)
• Branch circuit overload control (BCOC)
• Single source overload control (SSOC)
• Energy storage system (ESS) operating modes

ESS Operating Mode Identification

Confirm which PCS ESS operating mode applies to your product:

• Unrestricted mode
• Export only mode
• Import only mode
• No exchange mode

Applicable Testing Requirements

Depending on function implemented in PCS one or more of the following tests are applicable for each function from UL 3141 and ULC/ORD-C3141:

• Normal operation tests for source control or source and load control PCS
• Step change in load test for multisource PCS
• Step change in generation test for multisource PCS
• Normal operating tests for SSOC PCS
• PCS functional tests for PEL and PIL
• Loss of control circuit abnormal tests
• ESS operating modes
• Scheduling tests

What is the Difference Between UL 3141 Outline of Investigation (OOI) ED.2 and ULC/ORD-C3141:2025?

Both are the same except the standard references in ULC/ORD-C3141 are replaced with Canadian standards and installation code requirements as per Canadian Electrical Codes.

How Intertek Can Help

Intertek provides comprehensive testing and evaluation services for power control systems in accordance with UL 3141 and ULC/ORD-C3141 requirements.

Testing can be performed at:

• The manufacturer's facility
• The customer's site
• An Intertek laboratory

In addition, Intertek's technical experts can help manufacturers:

• Determine which UL 3141 and ULC/ORD-C3141 tests apply to their specific system
• Develop an appropriate testing strategy
• Understand testing procedures and compliance requirements
• Identify the equipment needed to conduct testing efficiently

With extensive experience in renewable energy, energy storage, and grid-interactive technologies, Intertek helps manufacturers navigate the UL 3141 and ULC/ORD-C3141 certification process with confidence, reducing project delays and accelerating market access.