1. Kenneth A. Stone
Senior Automation Specialist
UL508 Standards
Water Environmental Association of Texas (WEAT) Seminar
January 18, 2017

2. AGENDA
1. UL vs. NEMA
2. UL508, 508A, and 508C
3. OPEN vs. ENCLOSED

3. UL vs. NEMA

4. What is the difference between a NEMA Classification and a UL Type rating?

5. NEMA - Definitions
Example – NEMA 4 (Water and Dust Tight)

6. UL Type TESTED and CERTIFIED to meet a definition
Example – Type 4 (Water and Dust Tight)

7. UL508
Related UL Standards

8. 508 Standard for Industrial Control Equipment
508A Standard for Industrial Control Panels
508C Standard for Power Conversion Equipment
508B Outline of Investigation for Relays used in Information Technology (IT) Equipment 508E Outline of Investigation for IEC Type 2 Coordination Short Circuit Tests of Electromechanical Motor Controllers in accordance with (IAW) with IEC Publication I Outline of Investigation for Disconnect Switches Intended for Use in Photovoltaic Systems

9. UL508 UL508 Devices for controlling or protecting electric motors.
These requirements cover industrial control devices, and devices accessory thereto, for starting, stopping, regulating, controlling, or protecting electric motors. These requirements also cover industrial control devices or systems that store or process information and are provided with an output motor control function(s). This equipment is for use in ordinary locations in accordance with the National Electrical Code, NFPA 70.
Devices for controlling or protecting electric motors.
Devices that store or process information for controlling or protecting electric motors.

10. Industrial Control Panels using UL508 devices
UL508A
UL508A
These requirements cover industrial control panels intended for general industrial use, operating from a voltage of 600 volts or less. This equipment is intended for installation in ordinary locations, in accordance with the National Electrical Code, ANSI/NFPA 70, where the ambient temperature does not exceed 40°C (104°F) maximum.
Industrial Control Panels using UL508 devices

11. Power Conversion that uses UL508 devices
UL508C
UL508C
These requirements of open or enclosed equipment that supplies power to control a motor or motors operating at a frequency or voltage different than that of the input supply.
These requirements cover power-supply modules, input/output modules, Silicon Controlled Rectifier (SCR) or Transistor output modules, dynamic braking units, and input/output accessory kits for use with power conversion equipment.
Power Conversion that uses UL508 devices

12. What is the relationship between UL508, UL508A, and UL508C?

13. MOTOR CONTROL
DEVICES

14. MOTOR CONTROL
DEVICES
Power
Conversion
Devices

15. MOTOR CONTROL DEVICES Power Conversion Devices Industrial Control
Panels

16. UL508
UL508C
UL508A

17. OPEN vs. ENCLOSED

18. What do these labels tell us?
Enclosure Labels
What do these labels tell us?
Enclosed vs. Open
Enclosed – An Industrial Control Panel provided with an enclosure AT THE FACTORY.
“CABINET”
Open – An Industrial Control Panel that includes internal wiring, field wiring terminals, and components mounted on a subpanel without a complete enclosure. The enclosure is intended to be supplied/completed AT THE INSTALLATION.
“BACKPLANE”

19. PRACTICAL APPLICATION

20. 19.5 No covering is required across the bottom of a floor mounting enclosure when the lower edge of the enclosure is within 6 inches (152 mm) of the floor and when live parts within the device are at least 6 inches above the highest portion of the lower edge of the enclosure.
Section 19 – Enclosure Openings
UL 508A STANDARD FOR SAFETY
Industrial Control Panels

21. PANEL MOUNTING TECHNIQUES
Free-Standing
Floor Mount
Wall Mount
Pedestal Mount

22. 19.5 No covering is required across the bottom of a floor mounting enclosure when the lower edge of the enclosure is within 6 inches (152 mm) of the floor and when live parts within the device are at least 6 inches above the highest portion of the lower edge of the enclosure.
Section 19 – Enclosure Openings
UL 508A STANDARD FOR SAFETY
Industrial Control Panels

23. PANEL MOUNTING TECHNIQUES
Free-Standing
Floor Mount
Wall Mount
Pedestal Mount

24. QUESTION:
How far from the ground must the lowest live part be mounted in a free-standing enclosure such that no gland plate is required for openings in the bottom of the cabinet?

25. 19.5 No covering is required across the bottom of a floor mounting enclosure when the lower edge of the enclosure is within 6 inches (152 mm) of the floor and when live parts within the device are at least 6 inches above the highest portion of the lower edge of the enclosure.
Section 19 – Enclosure Openings
UL 508A STANDARD FOR SAFETY
Industrial Control Panels

26. ANSWER: 12 inches FREE-STANDING ENCLOSURE FREE-STANDING ENCLOSURE
Floor
Backplane 6”
FREE-STANDING
ENCLOSURE
Floor
Backplane 6”
FREE-STANDING
ENCLOSURE
Floor
Backplane
6+6 = 12” 6”

27. RESOURCE for QUESTIONS:

28. Thank you! PANEL DISCUSSION