Ul 508c pdf

Area of Interest:. Page URL Referral:. Page URL:. Form Language:. Accelerate global efficiency in your adjustable speed motor drive certifications. Accelerate global efficiency in your adjustable speed motor drive certifications Thursday, March 26, AM CDT Adjustable speed motor drives in variable speed applications are increasingly being used as a result of the high efficiency and reliability that they offer.

These drives provide precise electrical motor control and only use the energy required, unlike fixed speed motor drives that utilize excess energy.

PDF Price. Not a Member? This standard is not included in any packages. We have no amendments or corrections for this standard. Request Proposal Price. Proceed to Checkout Continue Shopping. Useful Links. Effective February 1, Standard Information. Standards Number and Name:. Effective Date: February 1, revised products. Impact, Overview, Fees and Action Required. New products are defined as: Any model or models that belong to a new series of drives not previously Listed or Recognized to UL C Any new model to an existing series currently Listed or Recognized to UL C that requires an associated change to the ratings or construction details section of the Certification report for that series As of February 1st, , UL C will be withdrawn.

This is the implementation date. Existing certifications to UL C will be allowed to continue to be certified to the requirements in effect for the product, provided there are no changes to the design after the implementation date that require a certification decision in accordance with the latest published version of the Standard.

For example, if changes to the design, ratings, or the use of alternate components requiring a certification decision are submitted after the implementation date, the device in its entirety will need to be evaluated to the new requirements of UL After February 1st, , only UL will be used for drive investigations.

X Title. UL is no longer a standard referenced as a standard for investigating clearances and creepages. Where protective separation is required, clearance and creepage requirements are greater than those required by UL and UL C Tables Surge protective devices cannot be used to reduce the overvoltage category and thus the required clearance for protective separation.

Impulse test for reduced clearances is not allowed where protective separation is required and only allowed for basic and functional insulation if a homogeneous electrical field is present.

UL allowed for impulse test in lieu of clearances in any construction. Alternatively, the inner layers can be investigated to solid insulation requirements. Note — where functional insulation is required the required clearances may be smaller.