Grounding Equipment, Neutral Grounding Devices Over 600 Volts, KDZC

Guide Information for Electrical Equipment for Use in Ordinary Locations



This category covers neutral grounding devices intended for use on systems having ac voltage ratings from 601 V to 38 kV. Neutral grounding devices are used for the purpose of controlling the ground current or the potentials to ground of an alternating-current system.

These devices are grounding transformers, ground-fault neutralizers, resistors, reactors, capacitors, or a combination of these. In addition, these devices may include current sensors, relays, audible and visual signaling and similar accessories.


Devices suitable for outdoor use are marked "Outdoor."

Enclosures are marked to indicate the exposure category (A, B or C) for which they are intended. Enclosures marked "Category A" are intended to be installed in areas accessible to the unsupervised general public; enclosures marked "Category B" are intended to be installed in areas accessible to authorized personnel only; enclosures marked "Category C" are intended for use in areas accessible to qualified personnel only.

Devices covered under this category are marked with the following information: Name of manufacturer, serial number, name of device, type designation, impedance (except resistors), number of phases as applicable, rated current, rated frequency, rated time, rated voltage, BIL of line, indoor or outdoor service, weight, volume of oil (as applicable), instruction book number or equivalent.


One of the following product identities appears on the product:

    Neutral Grounding Reactor

    Neutral Grounding Resistor

Other product identities may be used as shown in the individual certifications.


For additional information, see Electrical Equipment for Use in Ordinary Locations (AALZ).


The basic standards used to investigate products in this category are ANSI/IEEE 32, "Requirements, Terminology, and Test Procedure for Neutral Grounding Devices," and IEEE C37.20.3, "Metal-Enclosed Interrupter Switchgear."


The Certification Mark of UL on the product is the only method provided by UL to identify products manufactured under its Certification and Follow-Up Service. The Certification Mark for these products includes the UL symbol, the words "CERTIFIED" and "SAFETY," the geographic identifier(s), and a file number.

Alternate UL Mark

The Listing Mark of UL on the product is the only method provided by UL to identify products manufactured under its Listing and Follow-Up Service. The Listing Mark for these products includes the UL symbol (as illustrated in the Introduction of this Directory) together with the word "LISTED," a control number, and the product name "Neutral Grounding Resistor" or "Neutral Grounding Reactor," or other appropriate product name as shown in the individual Listings.

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UL, in performing its functions in accordance with its objectives, does not assume or undertake to discharge any responsibility of the manufacturer or any other party. UL shall not incur any obligation or liability for any loss, expense or damages, including incidental or consequential damages, arising out of or in connection with the use, interpretation of, or reliance upon this Guide Information.

Neutral Grounding Devices Over 600 VoltsNeutral Grounding Reactors Over 600 VoltsNeutral Grounding Resistors Over 600 Volts
Last Updated on 2013-05-16
KDZC.GuideInfo KDZC Active 20130516 20060831

The appearance of a company's name or product in this database does not in itself assure that products so identified have been manufactured under UL's Follow-Up Service. Only those products bearing the UL Mark should be considered to be Certified and covered under UL's Follow-Up Service. Always look for the Mark on the product.

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