Horsepower Rated Enclosed Switches Rules 28-500 (page 145)

A horsepower rated enclosed switch (fused or un-fused) which has not been specifically approved as a motor controller, is not acceptable as a motor controller.

The presence of a horsepower rating on a switch is not adequate proof that it has been certified as a motor controller; it is only an indication of the maximum size of motor, for which the switch has been tested to safely disconnect all ungrounded conductors of the circuit at the point of supply simultaneously.

A motor controller however is tested to C22.2 No. 14-95 Industrial Control Equipment. This Standard applies to control and protective devices, and accessory devices rated at not more than 1500 V, for starting, stopping, regulating, controlling, or protecting electric motors.

There is also a difference in the endurance test requirements for a horsepower rated enclosed switch and a motor controller. Specifically, a horsepower rated fusible switch is required to withstand 6000 operations at rated current at 75-80% power factor plus 4000 operations at zero current.

A motor controller (across the line starter) must withstand 1000 operations at twice rated current at 40-50% power factor.

Evidence that an enclosed switch has been certified as a disconnecting means to CSA Standard C22.2 No 14 must be obtained if it is to be considered acceptable as a motor controller.

This Bulletin does not apply to switches forming part of approved combination starters.

CSA standards C22.2 No 4, Enclosed Switches, Scope and Clause 6.6

C22.2 No 14 Industrial Control Equipment, Scope and Clause 6.6


CSA Standard C22.2 No 14-95, currently contains requirements for manual motor controllers/starters for the starting and stopping of electric motors.

Rule 28-602 (3) (b) of the Canadian Electrical Code, Part 1 (C22.1) allows the use of manual motor controllers/starters as a disconnecting means for a motor, motor starter or motor controller of a single motor or a group of motors.

Some manual motor controllers have been inappropriately applied (i.e. Used as a motor branch circuit disconnecting means).

Some manual motor controllers also provide electrical isolation.

The purposes of this T.I.L are to:

1. allow for the evaluation and identification of manual motor controllers intended for use as a motor disconnecting means;

2. allow for the evaluation of manual motor controllers providing electrical isolating means;

3. ensure consistency of requirements with CSA Standard C22.2 No.4, Enclosed Switches;
"Evidence that an enclosed switch has been certified to CSA Standard C22.2 No 14 must be obtained if it is to be considered acceptable as a motor controller.

Tony Moscioni
Electrical Inspector
Electrical Safety Authority