Industrial Control Panel Design Solutions


Siemens AG

Verify ID:


Expiration date:

September 01, 2020 - December 31, 2021

Verification Mark

Process Information

Door interlocking for distributed industrial control panels according to UL 508A and NFPA 79.
To protect persons from injuries caused by electricity, control panels that are operated in the USA must be designed so that they ensure proper protection against direct contact. This means that no live parts can be touched under normal operating conditions.
Relevant USA standards specify that doors of enclosures shall be interlocked applied in industrial control panels (UL508A) for industrial machinery (NFPA79). At the same time, enclosures shall be accessible for maintenance and service purposes by qualified personnel. This application solution enables electrical engineers to comply easily with all requirements, while at the same time saving effort and costs.
The application example comprises 3 options:
•  Electronic door interlocking with LOGO!
•  Electric door interlocking

Applicable To:

“Door interlock for distributed control panels” Application solution, V1.0

Marketing Claim Verified by UL

Application solution exceeds the design requirements of ANSI/UL508A and NFPA79

Verification Method

Design characteristics, functional sequence, circuit diagrams and bill of materials of the following document(s) were reviewed for alignment with UL 508A Ed. 3-2018, Standard For Industrial Control Panels and NFPA 79:2018 Electrical Standard for Industrial Machinery: “Door interlock for distributed control panels” Application solution, V1.0 This document was reviewed in respect of UL508A clause 66.1.3 and NFPA79 clause No manufactured product was assessed under the scope of this assessment.

About the Company

Efficient control panel engineering for the North American market with Siemens With the range of application solutions from Siemens, you can easily optimize your control panel engineering. From preparation and design to construction and all the way to service and support, we offer you a perfectly coordinated control panel solution for the North American market. With expert know-how, tools and data for digitalization in engineering, and an aligned product and system portfolio, we ensure long-term success and greater competitiveness. Find out more about Integrated Control Panels under: More details for the North American Market:

What is UL Verification?

UL Verification is an objective, science-based assessment that confirms the accuracy of marketing claims. Our independent assessment process scrutinizes the validity of specific advertising or promotional statements, giving you a way to separate verified fact from fiction.