K. J. Certification Co. Ltd.
EC Machine Directive
Machine safety inspection &risk assessment
Electrical safety inspection EN60204-1
UL 508 STD
ISO 9001 Quality System
ISO 14001 certification
ISO 13485 certificate quality of medical devices
CE Medical Devices Directive


Applicable standards in North America

▨ UL 508 safety standard of product scope:

1. These requirements cover industrial controls panels intended for general industrial use, operating from a voltage of 600 volts or less. This equipment is intended for installation in ordinary locations, where the ambient temperature does not exceed 40° C (104° F) maximum, in accordance with the National Electrical Code, ANSI/NFPA 70-1996.
2. This equipment consists of assemblies of two or more components, such as motor controllers, overload relays, fused disconnect switches, circuit breakers, and related control devices such as pushbuttons, pilot lights, selector switches, timers, control relays, and similar devices, with associated wiring, terminal blocks, and similar components.

Definition of electrical circuits as per standard UL508A (chapter 2 & 6)
Two type of power circuits are defined :

  • feeder circuits : intended exclusively to supply power
  • branch circuits : connected to a load with or without control functions.
SCCR (short-circuit current rating) of the control panel -- UL508A General rule :

The SCCR is obtained using the lowest SCCR value in each of the branch circuits.



UL508A STD.docx downloads>
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