IEC/UL 60950-1 Application Guideline 1.2.5-1

(Sub)CLAUSE/ANNEX HEADING: Connection to the Supply
(as Applicable):,, 3.2.4


Type of Issue:
Occasionally ITE intended for use in a commercial or industrial environment is provided with an appliance inlet complying with IEC 60320 for connection of a detachable power supply cord with a matching 60320 configuration connector on one end, but a commercial/industrial plug configuration, such as a locking NEMA L5-15 or L5-20, on the other. This typically is done because the ITE has relatively low power consumption and is a global product, yet the manufacturer wants the additional reliability associated with the commercial/industrial plug configuration and some of the allowances 60950-1 permits for Pluggable Equipment Type B configurations.

Since IEC 60320 appliance inlets are associated with household (i.e., Pluggable Type A) ITE, can the equipment still be considered Pluggable Type B in this case? If so, what additional considerations/requirements should apply related to the intended power supply cord set?


Relying strictly on the definitions of Pluggable Equipment Type A and B in and, this equipment would be considered Pluggable Equipment Type A by nature of its employment of an IEC 60320-1 appliance inlet. Generally, ITE with an IEC 60320 appliance inlet is Pluggable Equipment Type A.

However, additional considerations can be introduced into this classification of the equipment based on the construction, intended use of the product, and accompanying safety instructions.

The subject equipment can be considered Pluggable Type B if the following conditions are met.

  • The ITE is not intended to be installed in a home, school, office or other location that typically involves likely interaction of the ITE with untrained Users.
  • The ITE is intended to be installed and maintained by Service Personnel, and the safety instructions state this.
  • The power supply cord set employing the appropriate type plug configuration is provided with the ITE and described in the certification Report.
  • The attachment plug on the cord set is either a 15 A or 20 A configuration (e.g., L5-15 or L5-20). [Typically, the appliance inlet will be a C20 configuration, with a 16A (IEC) rating, which is suitable for use with both plugs (considering the NECís 80% rule since ITE is continuously operated).]
  • To reduce the risk of replacement of the original power supply cord with a power supply cord that may employ a non-industrial (i.e. Pluggable Type A) type plug, or installed in a location that the equipment was not intended to be installed in, the installation instructions should indicate that any replacement of the power supply cord should be conducted by a Service Person, and the same type cord and plug configuration should be utilized. Additionally, information on restrictions on intended installation location should be provided.
  • The symbol (ISO 7000-0434, exclamation point in a triangle) is provided as a marking adjacent to the appliance inlet.


There is a valid concern that if ITE is supplied with an appliance inlet complying with IEC 60320-1, which is the component standard for Appliance Couplers for Household and similar General Applications, that there is the possibility that the detachable power supply cord originally supplied with the ITE may be replaced in the field with another detachable power supply cord set with a different attachment plug cap. Therefore, the ITE should be Pluggable Equipment Type A.

However, for some constructions intended for limited applications those concerns can be mitigated by use of suitable instructions/markings. This Application Guideline provides the associated conditions.

This subject was discussed with the Bi-National Working Group (BNWG) for CSA/UL 60950-1 at a previous meeting (as documented in the June 30, 1999 Meeting Report). There was support from the BNWG for introducing some flexibility for limited applications.


    Interpretation Systems:

Only the on-line electronic version of this document is considered current.

The IEC/UL 60950-1 Application Database is a subscription-based Internet service that provides a source of reference for understanding and applying the requirements of the Standard for Safety of Information Technology Equipment, IEC/UL 60950-1. These guidelines are not intended to take the place of the requirements in the Standard, nor to establish additional requirements.

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