CSA C227.5:08 (R2023)
Three-phase live-front pad-mounted distribution transformers
This is the first edition of CSA C227.5, Three-phase live-front pad-mounted distribution transformers. A previous version of this Standard was published as CAN/CSA-C227.2-88 under the title Three-Phase, Live-Front, Pad-Mounted Distribution Transformers and withdrawn in 1995. The current version includes technical and editorial changes intended to bring this Standard into line with present practice.
This Standard was prepared by the Subcommittee on Overhead and Pad-Mounted Distribution Transformers, under the jurisdiction of the Technical Committee on Distribution Transformers and the Strategic Steering Committee on Power Engineering and Electromagnetic Compatibility, and has been formally approved by the Technical Committee.
This Standard has been developed in compliance with Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group.
This Standard specifies requirements for three-phase live-front pad-mounted distribution transformer units that
(a) consist of a transformer and a separable or integral cable entrance compartment;
(b) are rated 75 to 3000 kV-A and intended for operation on three-phase underground distribution systems having the preferred rated voltages specified in Tables 1 and 2; and
(c) are intended for mounting outdoors on pads without additional protective enclosures.
This Standard does not apply to equipment involving enclosures for housing a separate three-phase transformer or a bank of single-phase transformers (see CAN/CSA-C2.1).
Note: It is possible that transformers complying with this Standard will, if operated by a body other than an electrical utility, be subject to additional requirements specified by the electrical inspection authority having jurisdiction.
This Standard allows for the replacement of a live-front pad-mounted unit by another unit of the same basic physical size from a different manufacturer without modification to cables or pad. This Standard covers terminal arrangements for both radial and loop-feed systems, including certain minimum and other dimensions.
Note: This concept should not be understood to imply that the cable entrance compartment of one manufacturer's transformer will be compatible with that of another manufacturer's transformer.
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