What is Electrical Design?
Electrical design entails planning, creating, testing or supervising the development and installation of electrical equipment. Many electrical design projects start from an idea, or for the private industry is often thinking about a product being modelled or developed for market. Electrical design projects might represent a new marketable product or might seek to improve an existing product or system.
The electrical design engineer still requires full understanding of the fundamentals of electrical engineering principles. With the availability of a database system, different task programmes/modules, various planning, design, and analysis studies can be carried out.
The Electrical Design Process Condensed
An electrical design goes through several important stages of development. First, the designer must understand the scope of the project. Then, the designer defines and designs each component (such as general office areas, specialized machinery, and power distribution equipment) to recognized industry standards. Finally, these individual components are compiled to form the final presentation for the design.
Focal Points for Electrical Designers
The electrical design process is a multiple step method for problem solving. Electrical designers often need to focus on topics that are encounter quite often in their work. Electrical designers often work very closely with the following, that can either be a nuisance, or common knowledge for experienced electrical designers. Making sure that these topics are in the back of electrical designer’s minds is the important part:
Regulations and Standards
Electrical Reference of Components
Voltage System Used on Site
Avoiding Possible Failure Modes
- Electrical Safety
Determining Applicable Standards (English Only)After each component in the plan has been selected, the step is to design each part to industry-recognized standards, as well as any additional standards set forth by the local jurisdiction for commercial or industrial occupancies. The primary industrial standard is the National Electric Code (NEC), published by the National Fire Protection Association (NFPA). The NEC is revised every three years and results in the publication of a new edition. It is good practice to make sure that your product is up-to-date with the recent edition revisions. Although the code is applied at a national level, some local jurisdictions may have additional standards that exceed the requirements of the the NEC or they may be use a previous edition of the code.
Some projects will also have additional requirements based on their specific components, such as those including specialized electrical equipment. An electrical designer should always consider manufacturer guidelines for specialized equipment and use the appropriate electrical equipment standards set forth by the manufacturer for overcurrent protection sizes, specialized grounding requirements, and so forth. These specialized requirements may need that additional specialized wiring practices be observed; when this is the case, these specialized requirements must be documented on the plan.
Designers must also consider the standards of the National Electrical Manufacturers Association (NEMA), which includes standards for motor lead identification, transformer terminal markings. plug and receptacle devices, and amperage ratings. Designers must also consider the standards for the Electrical Apparatus and Service Association (EASA), which provides current and updated information for motors and controls.
For projects that include new or upgraded parts for distribution systems served from local utility, electrical designers must consider any requirements set forth by the utility company. These methods may dictate the wiring methods and equipment required for proper distribution form the serving utility to the customer. Calculated load values must reference manufacturer guidelines to ensure that distribution systems will support these loads.
In all cases, designers must not only have solid electrical knowledge and a thorough understanding of the electrical calculations and their necessity, but also awareness of the application of all relevant code and standards utilized within the electrical industry.
Creating the Electrical Plan
Once the various parts and applicable standards have been determined, the designer begins, compiling those parts to form the electrical design and complete a set of plans.
In the past these plans took the form of hand-drawn blueprints, but today most plans are created digitally using computer-aided design (CAD) software tools. Digitized plans are easier to revise and transmit than those drawn with pen and pencil.
On the plans, each device should be referenced using the appropriate electrical symbols. Electrical symbols allow for universal recognition of each part by the many persons who will be working on the project so that they can estimate cost appropriately and construct the project to the specifications.
Making sure that the correct symbols are utilized and written on the final design is vital. The design symbol list should be updated with the correct symbols and their definition. Occasionally the need may arise for a symbol that has not been developed (such as a newer energy-saving or energy management device). In this case, the designer may create a new symbol for the electrical design plan, as long as it is added to the symbols list included in the plan.
Understanding of various system voltages used in electrical systems is of great importance in their design and maintenance. Knowing how the loads are connected between phases and between phase and neutral will enable the electrical designer to properly design and specify the components of an electrical system and enable maintenance personnel to safely maintain and operate these systems.
There are many types of voltages for power supply, and knowing which one is available is step one. The voltage supply must be known from the utility company supplying it, not all servicing voltages are available for any load. For example, three-phase service may not be available for residential buildings, minimum load requirements may be specified for larger loads, and so on. The electrical designer is responsible for determining the service voltage requirements. Do not assume you know what power source you will be using, and design a device for one type of power source when its location won’t output such power.
Plan to Avoid Failure Modes
Failure modes happen over time, and are often hard to design to avoid. Electronic components have a wide range of failure modes. These can be classified in various ways, such as by time or cause. Failures can be caused by excessive temperature, excessive current or voltage, ionizing radiation, mechanical shock, stress impact, and many other causes. Failures most commonly appear near the beginning or near the end of the components life-cycle. Applications such as aerospace systems, life support systems, telecommunications, railway signals, and computers use great number of electronic components. Analysis of the statistical properties of failure can give proper guidance in designs to establish a certain level a reliability. A list of failure modes is displayed below:
Printed Circuit Board Failure
Passive Element Failure
- MEMS Failures
What ever environment that your product will be in, thorough research is needed to proper design the product to withstand the surrounding environment. Last thing you would want is you forgot to incorporate that the ambient temperature could reach up to 300 Fahrenheit (Exaggerated) and your electronic was designed to handle room temperature.
Input Voltage Caused Massive Overheating
Electrical Equipment Safety
No matter all the precaution people take around electricity, it only takes that one moment when a simple mistake could turn into a life threatening situation. Developing new products takes a great deal of time simply designing it to customer specifications. But, it is an unavoidable truth that safety is still the number one unannounced customer requirement. Those who will build it, those who will handle it, those who its designed to be used for, and those who were never supposed to touch it.
Either way you look at it, the risk of electrical shock is still present with every electronic device today. The only thing that we can do is take preventive measures and minimize the chance of someone receiving an electric shock. Has all the components met all standards and guidelines? Has it met the necessary guideline for the industry that it is going to be used in? Last thing you want is for a new baby monitor to have an exposed section of wire. But, realistically this product for this reason would probably not make it to market. Have all measures been taken that you feel everything you have possibly done to prevent any harm or damage from your device been taken?
Safety is the number one unspoken requirement that all electronic devices need to meet. Once this goal is met you can rest peacefully at night that your product won’t harm anyone.
Rethinking the Electrical Design Process
No matter how little or how much experience someone has as an electrical designer, it is always good to take a high-level view of the work that is done. Some of the topics discussed here may seem like, “Yeah this is common sense”, but sometimes its nice to remind ourselves that this is the job, and the electrical design process maybe a method that is often neglected, or in some cases never used. People become their work, and understand everything that goes on around them. Very little change may happen and it is often nice to look at things from a fresh perspective. Electrical designers just need to sit down and remember what it was like when they first started, in order to avoid the big oops at work that any rookie on the job could of told you.
Ever had a mistake that you thought to yourself, “I learned this in school… I knew this before I even started the job”?