I was recently asked this question by a group of electrical engineers in conjunction with the NFPA 20 requirement for an overcurrent device protecting feeder conductors to the fire pump controller from the normal power supply source to carry a fire pump locked rotor current indefinitely.
This article will focus on overcurrent protection and conductor sizing for low-voltage transformers in the Canadian Electrical Code.
Section 8 is a general section of the CE Code. It provides the information you need to select the conductor ampacities and equipment ratings for consumer’s services, feeders, and branch circuits.
Although “control devices” are not specifically defined in the Canadian Electrical Code, Part I, application of control devices is well-described throughout the Code, and particularly in Section 14.
Supplementary protectors have been recognised in Canada since the publication of the standard in 1989, CAN/CSA C22.2 No.235 Supplementary Protectors.
Quite often we look at the requirements of the CE Code without any concerns, as clarity of the literal text (and of the intent behind this text) appears to be obvious. Rule 8-304 of the CE Code should be one such requirement.
Section 8 is a general section of the CE Code. It provides the information you need to select the conductor ampacities and equipment ratings for consumer’s services, feeders, and branch circuits
High voltage visible isolation has been required in Canada since the fifties. Visible isolation is the ability to see the blades of a switch or circuit breaker to determine if the device supplying a high voltage circuit is in the open or closed position.
The Code is a comprehensive document. Sometimes it can seem quite daunting to quickly find the information you need. Part 4 provides a guide to help users find their way through this critical document.
Section 8 of the CE Code is absolutely critical, as the accurate load calculations constitute the basis for selection of the appropriate conductors’ sizes in services, feeders and branch circuits