You are here: Home » Archives for motors
Tag: "motors"
By definition an electric motor is a device that converts electrical energy into mechanical energy. An electrical signal is applied to the input of the motor and the output of the motor produces a defined amount of torque related to the characteristics of the motor. If you think about the attraction and repulsion of the north and south poles of a bar magnet, you are on your way to understanding what has to happen inside the motor yoke. To achieve rotation there has to be some interaction between magnetic flux produced by electromagnetism within the motor. DC motors and AC motors accomplish this task in different ways.
This article reviews two very essential safety requirements of the Canadian Electrical Code for motor control circuits, grounding and why it’s so significant that control circuits be prohibited for use as motor disconnecting means.
It’s Complicated — you’ve probably seen this witty movie about divorce. Motor wiring rules are complicated too, but not nearly as amusing as the movie. This article reviews our complicated rules for motor supply conductors. When wiring is installed directly into a motor terminal box, Rule 28-104 tells us that the minimum conductor insulation temperature [...]
Motor wiring methods are covered in Rules 28-100 to 28-112 of the Canadian Electrical Code. Wiring up a motor may seem like a pretty simple job, but we still need to consider a surprising number of details for good compliance with the code. This article will review some of the more important CEC rules for [...]
Several of the rules in the Canadian Electrical Code are quite complicated, and it requires our close attention to get them right. This article discusses two of those rules, 28-604 for motor disconnects and 4-004 for underground conductor ampacities. One of the trickiest CE Code rules to follow and interpret correctly is Rule 28-604 Location [...]
The purpose of electrical codes is practical safe guarding of persons and property from the hazards associated with electricity. Numerous prescriptive requirements address safety from the minimum standpoint. Codes and standards are the minimum rules for electrical safety, so one can easily surmise that for electrical safety one must do at least what is required [...]
Series combination ratings are utilized to attempt to save money on some jobs. This article presents a simple checklist that can be completed by the contractor and/or designer when series rated combinations are proposed. The checklist is designed to be a single sheet that is double sided. The front side requires information for a specific [...]
Everyone understands the importance of good connections in business and in life generally. Good electrical connections are important too. The Canadian Electrical Code provides some important information and contains many rules on connecting electrical equipment. In this article we will cover a few of the many connection principles contained in the code.
Overcurrent protection for electrical equipment can be accomplished by several different methods. The general rules for overcurrent protection of conductors and equipment are found in Article 240 of the National Electric Code. Section 240-2 indicates Article 440 shall be used for protection of air-conditioning and refrigerating equipment. In Part C of Article 440, specifically Section [...]
Overcurrent protection for motors and motor circuits is a little different than the rules for conductors as specified in Article 240, because motor loads have different characteristics than general lighting and other loads. Motor circuits draw a large amount of current at initial start-up, usually around six times the normal full-load current (FLA) of the [...]
(1 votes, average: 4.00 out of 5)
