What Is UL 810 Capacitor Certification? A Complete Guide to Capacitor Safety Standards

UL 810 Certification is a critical safety standard for AC capacitors, especially those used in motors, HVAC systems, and power electronics. UL 810 capacitors must meet rigorous criteria related to dielectric strength, pressure relief, fault protection, and thermal endurance. These tests ensure that capacitors perform reliably under high-stress conditions without posing fire or electrical hazards, making them ideal for manufacturers looking to meet North American safety regulations.

UL 810 Capacitor Certification Requirements and Testing Procedures

To qualify for UL 810 Certification, capacitors undergo the following evaluations:

Dielectric Withstand Testing - Ensures the capacitor insulation can resist high voltage without breaking down.
Pressure Relief Testing - Verifies that the capacitor can safely vent internal pressure in the event of failure.
Overload and Endurance Testing - Confirms that UL 810 capacitors can operate under rated voltage and temperature for extended periods.

Why UL 810-Certified Capacitors Matter

Using UL 810-certified capacitors guarantees compliance with North American safety regulations. These capacitors are especially recommended for motor run applications, HVAC systems, and industrial power electronics, where component failure can lead to significant safety or financial risks. It minimizes the risk of component failure, enhances system reliability, and assures OEMs and end users of product quality.

Capacitor Classification Based on UL 810 Standard

According to this standard, capacitors can be distinguished according to their performance and structure, and are mainly divided into three categories:

Structural audit type (UL product category code CZDS2) ─ does not test the protection capability when internal abnormal short circuit occurs, and shall not declare the maximum effective fault current protection capability, but the maximum declared operating voltage is 7.2KV.
Internally protected type (UL Product Category Code CYWT2) - AFC maximum effective fault current (short circuit) protection capability needs to be declared, the maximum AFC is marked as 10000A.
Electrolytic Capacitors (UL Product Category Code CZEH2) – 600V maximum, subject to overvoltage and pressure relief testing.

How to Prepare for UL 810 Certification: Self-Testing Guidelines

Enclosure Requirements for Metal and Non-Metal Housings

For metal enclosures, the minimum thickness requirements are as follows:

Steel: at least 0.25 mm

Aluminum or copper: at least 0.41 mm
Only fully metal-sealed enclosures are eligible under UL product category CYWT2.

For non-metal enclosures, the plastic casing must be UL certified and comply with the following:

Flame class rating above V-2
Dielectric strength exceeding 5 kV

Requirements for Insulating Materials

For internal insulation, UL 810 generally mandates a fire rating higher than HB. However, if the insulation is exposed or partially exposed (e.g., as shown in certain capacitor structures), testing must follow UL’s standards for plastic enclosures.

Additionally, per UL 810 section 4.3.4, both the capacitor casing and any epoxy materials used must withstand temperatures higher than either 70°C or the capacitor’s rated operating temperature—whichever is greater.

Our Commitment to UL 810-Compliant Capacitor Manufacturing

At Lung-Chen, we manufacture capacitors that meet UL 810 Certification standards. Our production includes:

Careful Material Selection – We source UL-recognized insulating materials and housing components that meet flame resistance and dielectric strength requirements.
Precision Engineering – Our designs follow UL 810 classifications, including internally protected types, ensuring compliance with overvoltage and fault current standards.
Thorough Quality Control – Every batch is subjected to internal testing that simulates the UL certification process, minimizing risk and accelerating approval timelines.
Compliance-Driven Design – From metal casing thickness to epoxy thermal resistance, we incorporate all structural, material, and safety considerations from the start.
Customer Assurance – By aligning with UL 810 from the ground up, we ensure higher product reliability, longer service life, and a smoother path to market certification.

Whether you're sourcing capacitors for motor run applications or looking to meet UL-compliant standards, Lung Chen UL 810 capacitors are tested for safety and built for long-term performance. Contact us today to learn more or request a custom solution.