Preface

This is the first edition of CSA C22.2 No. 274, Adjustable Speed Drives, one of a series of Standards issued by CSA Group under Part II of the Canadian Electrical Code.

Prior to the release of this Standard, adjustable speed drives were certified by using CSA C22.2 No. 14 for industrial controls in conjunction with other CSA Group standards and bulletins so as to verify and test all drive related safety requirements. This Standard puts all of the relevant requirements into one document to facilitate this review. This Standard was written so as to mirror the requirements found in standard C22.2 No. 14 where applicable to maintain as much continuity as possible with existing standard practice for this type of equipment. Many of the tables contained in this Standard have been reproduced from C22.2 No. 14 and have retained their original table numbers so as to facilitate comparisons.

Although this Standard follows traditional North American practices for evaluating adjustable speed drives, the international requirements described in IEC 61800-5-1 were reviewed in detail and accommodated within this Standard whenever possible.

For general information on the Standards of the Canadian Electrical Code, Part II, see the Preface of CAN/CSA-C22.2 No. 0.

This Standard is considered suitable for use for conformity assessment within the stated scope of the Standard.

Scope

1.1
This Standard specifies requirements for adjustable speed drives with respect to electrical, thermal, and energy safety considerations. It applies to adjustable speed a.c. and d.c. electric drives connected to line voltages up to 34.5 kV, 50 Hz, or 60 Hz.

1.2
This Standard applies to the following:

a) power conversion, drive control equipment and interface circuits; and

b) servo drives and integral servo drive/motor combinations.

1.3
The equipment covered by this Standard is for use in ordinary locations in accordance with the Canadian Electrical Code, Part I (CEC, Part I).

1.4
The adjustable speed drives covered by this Standard are intended for use in an ambient temperature range of 0 to 40 °C.

Note: This Standard does not include requirements for equipment intended for use in an ambient temperature outside of this range. Additional investigation of the equipment is needed when equipment is to be used in ambient temperatures outside of this range.

1.5
Equipment intended for special applications can be subject to additional requirements not included in this Standard.

1.6

This Standard does not apply to solid state, single phase motor speed controls rated 300 V and less, 20A and less that are covered by CSA C22.2 No. 156.

1.7
This Standard does not apply to

a) traction and electric vehicle drives;

b) motors as covered by CSA C22.2 No. 100;

c) driven equipment;

d) cord connected drives; and

e) integrated ASDs (adjustable speed drives) where the motor and ASD are mechanically integrated into a single unit.

1.8
General requirements applicable to this Standard are given in the latest edition of CAN/CSA-C22.2 No. 0.

1.9
The values given in SI units are the units of record for the purposes of this Standard. The values given in parentheses are for information and comparison only.

1.10
In CSA Standards, "shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; "should" is used to express a recommendation or that which is advised but not required; "may" is used to express an option or that which is permissible within the limits of the standard; and "can" is used to express possibility or capability.

Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material.

Notes to tables and figures are considered part of the table or figure and may be written as requirements.

Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.