What is UL508?

1. What is UL508?

UL 508, the Standard for Safety For Industrial Control Equipment, covers industrial control and related devices rated 1500 volts or less used for starting, stopping, regulating, controlling, or protecting electric motors.
In order to get UL certification, there is three type of certifications, Listing, Recognition and Classification.

- UL Listing -
UL Listing means that UL has tested representative samples of a product and determined that it meets UL’s requirements.

- UL Recognition -
UL Component Recognition means that UL has evaluated components or materials intended for use in a complete product or system. These components are intended only for end-use products that may be eligible for UL certification.

- UL Classification -
UL Classification typically means that UL has tested and evaluated samples of a product with respect to certain properties of the product.

In UL508, generally required to have UL Listing Certification. The requirement is based on Electric construction supplier and UL certified equipment manufacturer.

2. Difference between UL508 and UL60950-1

Table 1 shows the difference of requirement between UL508 and UL60950-1

Table 1 Comparison of requirement for power supply
NoStandard UL508 UL60950-1
Determined by input voltage.
ex. Input voltage = 240V,
creepage between Pri.-Sec. : 2.4mm
Determined by internal operating voltage.
ex. Operating voltage = 250Vrms
creepage between Pri.-Sec. : 5.0mm
2Insulation Thickness 0.71mm or more is required for direct supported of uninsulated live part.
ex. Terminal block etc.
No requirement for Basic and Functional insulation.
0.4mm or more is required for reinforced isolation in case of single layer.
3Terminal block Field wiring terminal block certified by UL is required.(If no certification, additional test is required.) No requirement of Field wiring terminal block certification.

3. UL508 (Listing) Certified product.

PBA10F - PBA150F ((-N option), PLA15F - PLA30F (except -J option)
PJA100F - 150F (except -J option), KH series, KL series, KR series
For more details, please see Specification sheet.

Technical Product-related Inquires