CAN/CSA-E742-94 (R2009)
1. Scope and object
1.1 Scope
This standard is applicable to stationary or portable, single-phase
or polyphase, air-cooled isolating and safety isolating transformers,
associated or otherwise, having a rated supply voltage not exceeding
1 000 V alternating current and 1 000 square root of 2 V unsmoothed
direct current and rated frequency not exceeding 500 Hz, the rated
output not exceeding:
- for isolating transformers:
25 kVA for single-phase transformers
40 kVA for polyphase transformers
- for safety isolating transformers:
10 kVA for single-phase transformers
16 kVA for polyphase transformers
The no-load and rated output voltages do not exceed:
- for isolating transformers 1 000 V a.c. and 1 000 square root of 2 v
unsmoothed d.c.;
- for safety isolating transformers 50 V a.c. r.m.s., and/or 50 square
root of 2 V unsmoothed d.c., between conductors or between any
conductor and earth.
Rated values are indicated in supplementary parts, Chapters II and
III, appropriate to each type of transformer.
This standard is applicable to those isolating transformers used when
the installation rules call for the separation of circuits for the
supply of certain parts of the circuit or of equipment (shavers,
portable tools, lawn mowers, etc.).
This standard is applicable to safety isolating transformers used for
the supply of circuits for safety extra-low voltage equipment (toys,
bells, portable tools, handlamps, etc.).
It is also applicable to transformers associated with specific items
of equipment, to the extent decided upon by the relevant IEC Technical
Committees.
This standard is applicable to dry type or encapsulated transformers.
It is not applicable to transformers filled with liquid dielectrics or
pulverised materials.
In locations where special environmental conditions prevail,
particular requirements may be necessary in accordance with IEc
Publication 364-5-51: Electrical Installations of Buildings, Part 5:
Selection and Erection of Electrical Equipment. Chapter 51: Common
Rules.
This Standard applies to the safety of such equipment designed to be
installed and used in accordance with the rules of the Canadian
Electrical Code (CEC), Part 1.
Note: Manufacturers designing products for use in Canada may find a
helpful summary of the equipment-related requirements of the CEC, Part
1, in CSA Publication Spe-2000.
1.2 Object
The main object of this standard is to establish safety requirements
for isolating transformers and safety isolating transformers.
OEN:
CSA
Langue:
English
Code(s) de l'ICS:
29.180
Statut:
Annulée
Date de Publication:
1994-06-29
Numéro Standard:
CAN/CSA-E742-94 (R2009)