Devices used in ICP panels

In order to have a UL Listed industrial control panel, the devices and components that make up the panel must also meet the requirements of UL. Questions often come up about whether or not specific devices already meet UL requirements. This section outlines how to find out if specific devices are covered or if additional investigation would be required.

Devices already covered by UL508A, the Standard for Safety of Industrial Control Panels

UL devices already covered by 508A do not require additional review and should not be included in the procedure or in the UL Recognized Component parts list.

Determining whether a device is covered by UL508A

Components/assemblies that may warrant investigation are covered in the "exception" to Paragraph 3.1 of subject 508A.The following list should also help determine if devices are covered.

UL Listed devices:

UL's "electrical construction materials directory" (green book) indicates specific product categories suitable for use in panels that do not need further investigation. These devices should not be included in the procedure.

UL Recognized Component devices:

Non-solid state industrial devices NIMX2 (paragraph 3.3 of subject 508A)

• Components under NKCR2, NKPZ2, NLDX2, NLRV2, and NRNT2 are suitable for use in panels and generally require no further investigation.
• UL Recognized Components in categories NMFT2, NMMS2, NMTR2, NRAQ2 and NRGU2 that employ solid-state switching devices for direct control of a power circuit load i.e., motor, heater, etc., will need to be investigated.
• All UL Recognized Components under category NJHU2 motor controllers over 1500 volts are not intended to be used in industrial control panels evaluated to UL 508A.

Solid-state industrial NIMX2 devices (paragraph 3.3. 'exception' of subject 508A)

UL Recognized Components covered under the categories NKCR2, NKPZ2, NLDX2, NLRV2, NMFT2, NMMS2, NMTR2, NRAQ2, NRGU2 and NRNT2 which employ solid-state switching devices for direct control of a power circuit load will need to be investigated. If the components are found to be suitable for use in panels, they will need to be added to the procedure along with any special use conditions.

Non-industrial (NIMX2) devices (paragraph 3.3 of subject 508A.)

UL Recognized Components (other than solid-state components) covered under the categories NKCR2, NKPZ2, NLDX2, NLRV2, NMFT2, NMMS2, NMTR2, NRAQ2, NRGU2 and NRNT2 and are identified in the yellow book as being non-industrial i.e., air-conditioning/ refrigeration equipment will need to be used in a class 2 transformer circuit or a low voltage limited energy circuit. Please see paragraph 3.6 or 19.1 of subject 508A respectively for details on these circuits.

These non-industrial components, when used in one of these two circuits, do not need to be included in the procedure. If it cannot be used in a low voltage circuit, the component shall be investigated and, if found suitable for the intended use, will be added to the procedure along with any special use conditions.

Any other UL Recognized Component device

Suitability for use in panels shall be determined by reviewing the UL component report for the device

These components, if found suitable, will need to be included in the procedure along with any special use conditions.

Devices not covered by 508A

For UL devices not already covered by subject 508A, additional review is required. Please provide the following:

• The manufacturer's name.
• Catalog number.
• UL file number and product category.
• Electrical rating.