Monthly Archives: November 2015

The Mystery Of Electrical Components Continued

Many of the electrical components we use on a daily basis in our homes and businesses are a mystery to us.  Not many people are concerned with their electrical systems or those electrical systems that supply heat, electricity and such until they have failed.  Once they stop functioning and our lives are put on hold or business is delayed we finally become concerned with all the inner workings of the equipment.  In a previous installment we reviewed electricity its flow along with three main electrical components: disconnect switches, main breakers and fuse panels.  In this installment on the mysteries of electrical equipment we will examine branch circuits, switches, outlets and wiring.

Wiring: In every home you will find various wires and cables.  The three main options in wiring within a home consist of Romex, bx cable or wiring encased within conduit. Romex is the name of a type of plastic insulated wiring that is comprised of non-metallic sheath.  This is normally the wiring that is used in dry, protected areas such as stud walls and side joists.  It is the wiring used when there is no risk of mechanical damage or subjected to excessive heat.  Bx cable is also known as armored cable.  This cable encases wires using aluminum or flexible steel sheaths that are semi resistant to damage.  The safest method of wiring when it comes to durability is single strands of conductor wiring pulled through a conduit.  These three types or wiring are used to carry the electrical current from the main panel to the device needing it.  It is crucial that the wiring that is installed is properly sized for the load requirements that are anticipated.

Outlets:  Electrical outlets are used to plug in portable electrical devices.  An outlet consists of a hot feed, a neutral and aground.  Special outlets should be installed in areas with moisture present as normal grade home outlets are not equipped to handle getting wet.  Outlets are found throughout homes are usually places strategically in consideration of a rooms layout and where there appears to be a need to electricity.

Switches:  A switch is similar to an electrical outlet in that they are placed in areas throughout the home.  They provide electricity to devices that are stationary such as lights and fans.  The switch will turn the devices on and off.  Switches come in single-pole, three-way, four-way and dimmer.  The purpose of the different switches is to offer a variant to the flow of current that goes to the lights and fans within the home.

Branch Circuit:  In a home there is a main circuit breaker that has several smaller branch circuits that is feeds electrical current into.  A branch circuit feeds electricity into breakers to power switches and outlets.  Most circuits can be either 120 volts or 240 volts.  A 120 volt circuit requires a single pole breaker and only uses one phase of electricity.  This is a light circuit meant to power between 15 and 20 amps. It is good for outlets and switches.  A 240 volt circuit uses a two pole breaker and uses both phases of the circuit.  A 240 volt circuit will power larger appliances such as electric ranges, electric stoves, central air units or hot tubs.  The appliance will not get electricity unless both phases are working.  This circuit also requires a two-pole 30 amp breaker.

J&P Electrical is a full service electrical equipment company.  At J&P, we supply contractors, end users and supply houses with new surplus, quality reconditioned and obsolete electrical equipment. Contact us today at https://jpelectricalcompany.com for all of your bus plug, circuit breaker, switchboard, fuses, disconnects and more.

Preventive Electrical Maintenance For The Winter Season

The winter season is upon the north.  Many of us are starting to get buried under piles of snow and are soon to be locked inside hoping for a break in the freezing temperatures.  It is the perfect time to make sure that all electrical systems have been inspected for potential electrical component problems.  Proper maintenance and regular upkeep on the industrial electrical systems in your home will prevent having to find emergency maintenance service when temperatures are below freezing when being without heat or electricity is dire.  Proper preventative maintenance on electrical systems can prevent a disaster later on.

Why should proper preventative maintenance on electrical systems be performed?

The power requirements, during the winter months, are far greater than any other time of the year.  There is a constant struggle to keep industrial buildings warm in order to prevent electrical systems used in the operation of the business running efficiently.  All the while industrial facility’s and plant managers are looking to improve their efforts to lower power consumption and reduce expenses overall.  Programmable logic controllers should be employed by industrial companies to be trained and specialized in the equipment used throughout the facility.

With the above goals in mind there are a variety of issues, as listed below, that can be prevented with proper electrical preventative maintenance.

  • Circumvent electrical shorts that can lead to fires. When a current is overloaded electrical short circuits can occur. This could potentially lead to starting an electrical fire.  To avoid this remove any wires that have become exposed.  It is also important that load imbalances are avoided.  Excessive heat buildup, arcing and explosions can occur.
  • Detect electrical components that are running hot or not running according to the specifications stated. Before an electrical component fails it will most likely start to run hot.  Check running components such as transformers, motors, bearings and wires.  If it noted that they are running warmer than specified it is time to think about preventative replacement.  Refurbished electrical components can be purchased at a discount to allow industrial equipment to keep running efficiently without the expense of new components or replacement equipment.
  • Check for any loose connections. A loose connection on any piece of equipment can lead to fluctuations in power causing erratic operations and uneven power distribution between the wires.

Preventative maintenance should be a full time position that is filled by a trained specialist.  This one position can save the company both time and money.  With regular equipment maintenance companies are able to avoid unplanned downtime.  This leads to more regular production, better customer services and is cost effective.  Buying new equipment, down time, decreased production and hiring emergency repair services are all incredibly costly for any company.  Simple, regularly scheduled maintenance along with the use of refurbished electrical components allow for smooth operation within manufacturing.

J&P Electrical is a full service electrical equipment company.  At J&P, we supply contractors, end users and supply houses with new surplus, quality reconditioned and obsolete electrical equipment. Contact us today at https://jpelectricalcompany.com for all of your bus plug, circuit breaker, switchboard, fuses, disconnects and more.

Extending the Life and Reliability of Circuit Breaker Protection

Many hydropower plants have been in service for 60 or more years with circuit breakers that are well beyond their expected service life. Some of these circuit breaker designs require more maintenance over time and genuine replacement parts are often not available, potentially resulting in improper circuit breaker function, downtime and increased maintenance expenses.

Additionally, some circuit breaker designs require more and more maintenance over time and if genuine replacement parts are not available, this can result in improper circuit breaker function that can cause catastrophic failure.

The resulting conversions have simpler design, fewer components, reduced maintenance and readily available replacement parts. They also provide higher reliability, extended insulation life and can help increase safety for personnel.

Factors impacting a generator circuit breaker’s useful life

Circuit breakers used in generator applications can have various types of interrupting technologies, require special operating parameters and may have exceeded their original design life.

The circuit breaker’s performance and longevity depend on:

— Switching rates;
— Number of switching operations and current magnitudes;
— Maintenance costs;
— Availability and cost of renewal parts;
— Maintenance intervals;
— Maintenance outage times; and
— Environmental concerns such as oil, polychlorinated biphenyls (PCBs) asbestos and possibly sulfur hexafluoride (SF6).

These parameters not only affect system availability and reliability, but also impact the ongoing financial viability of the generating station. When considering whether to modernize power circuit breakers used in generator circuits, there are a number of options involving available technology upgrades to consider. In most scenarios, there will be some type of conversion involved.

Common terms for equipment life extension and modernization of generator circuit breakers

IEEE Standard Requirements for Conversion of Power Switchgear Equipment C37.59-2007 is a process standard that provides guidance and testing methodology for power circuit breakers.

The standard defines important conversion terms that should be noted and included in specifications that outline customer requirements for equipment life extension and modernization of generator circuit breakers. Familiarizing yourself with these terms will help ensure you are receiving the correct services to meet your needs.

— Conversion: The process of altering existing power switchgear equipment from any qualified design.
— Compartment adaptor: A removable device designed for insertion into a switchgear circuit breaker compartment that provides mechanical support and interlocking plus the primary and secondary electrical connections to allow insertion of a draw out circuit breaker that differs mechanically from that which originally occupied that circuit breaker compartment.
— Design verification: The process of design qualification, in accordance with all appropriate standards, of any conversion by means of design testing and/or evaluation, supported by justified technical evaluation and documentation.
— Modular assembly: A circuit breaker element, including interrupters, operating mechanism, and connecting terminals, or an alternating current contactor element, including interrupters, operating mechanism, and connecting terminals, that has been tested and qualified to the appropriate industry standards.
— Qualified design: Any power switchgear equipment that has been tested and certified to appropriate industry standards.

This before and after image of a reconditioned breaker exemplifies how the life of vintage electrical equipment can be extended using only qualified design parts.

— Racking: The act of moving a removable element physically between the connected position and the disconnected position in its compartment.
— Reconditioning: The process of maintaining existing power switchgear equipment in operating condition as recommended by the manufacturer’s instructions, using only qualified design parts. Reverse engineered parts (designs copied from existing parts by other manufacturers) are not considered to be qualified design parts unless specifically design verified.
— Replacement interchangeable circuit breaker: A circuit breaker that utilizes all new parts, has been design tested to IEEE Std. C37.09 or to ANSI C37.50-1989 or IEEE Std. C37.14-2002 as required, and requires no conversion of existing switchgear to maintain proper operation.
— Replacement non-interchangeable circuit breaker: A circuit breaker that utilizes all new parts, has been design tested to IEEE Std. C37.09 or to ANSI C37.50-1989 or IEEE Std. C37.14-2002 as required but requires conversion of existing switchgear to maintain proper operation.
— Retrofill: A conversion process that includes replacement of the circuit breaker and circuit breaker compartment functional components of a qualified design within a vertical section or compartment of a vertical section with functional components of a different qualified design.

Important notes:

— Circuit breakers used for generator service should also be design tested to IEEE Std. C37.013; and
— The term retrofit is not defined and is no longer used in IEEE Std. C37.59-2007.

Understanding different life extension and modernization solutions

Generator breaker conversion and modernization solutions are readily available from a number of sources. Site performance and financial requirements will drive the selection process. It is important to note the correct solution should provide the best long-range performance, so look for cost estimates and proposals from a number of sources. Typical solutions can be categorized as follows:

Reconditioning

If parts are available from the original equipment manufacturer, outage time is not an issue, the circuit parameters are less than or equal to the circuit breaker’s rating and the switching rate is low, reconditioning of the existing circuit breaker may suffice for at least three to five years. If OEM parts are not available for a rebuild, then the circuit breaker’s performance will be affected and a failure can occur. Reconditioning using third-party reverse-engineered parts, as cautioned by the IEEE Std. C37.59-2007, can be dangerous. Reconditioning does nothing to update technology or increase the circuit breaker’s capabilities. However, this is the lowest cost solution for extending operating life.

New replacement circuit breakers

These will either fit directly into a draw out arrangement or require minor structure or control wiring modifications to complete their interface. Complete stand-alone designs can be manufactured to replace existing fixed-mounted oil circuit breakers. In many instances, the fixed-mounted design can be replaced with a draw out configuration to enhance reliability and reduce maintenance outage time. The new design would be tested to the appropriate IEEE Standards.

Retrofill conversions of existing installations

Retrofill conversions are often good solutions, provided the existing enclosure has the capability and room to accommodate the conversion components. Newer technology and circuit breakers with increased capabilities can be interfaced into the existing enclosures. When installations are unique, a retrofill conversion is often the best solution. The cost is usually between that of new replacement circuit breakers and complete replacement.

Complete replacement

Installation of new switchgear with current technology circuit breakers is an always an option. Often extensive site preparation and reconfiguration is required to accommodate a different dimensional layout and new cabling is required. In addition, outage time, available space, conductor interfaces and total installed cost may rule out this option. This solution usually has the highest cost, but the cost difference for this option may afford increased efficiency and the safest equipment operation.

Simplifying circuit breaker maintenance through interactive training

To facilitate education and help address the knowledge gap, some vendors offer interactive video training modules to provide a starting point for circuit breaker maintenance and testing. Some of these available resources do not require any special software to operate and the vendors provide a portal for numerous test procedures, active animations and illustrations to guide personnel through maintenance and testing processes.

To help simplify life extension and modernization, some vendors offer interactive training programs with animations and illustrations to guide personnel through maintenance and testing processes.

Closing thoughts

Generator circuits may present special requirements for the circuit breakers intended to protect them. Industry standards are available to identify the requirements and demonstrate the required capabilities.

There are various methods available to extend the useful life of generator circuit breaker systems using reconditioning and conversions. Conversions also make it possible to modernize the system to current generator class circuit breakers. By incorporating newer interrupting technologies and other enhancements, a reduction in maintenance costs and reliability improvement can be realized.

Interactive digital training programs can also help accelerate the learning curve for maintenance personnel on new technology and existing testing techniques that are specific to generator class power circuit breakers.

Original Source: http://www.hydroworld.com/articles/hr/print/volume-34/issue-7/articles/extending-the-life-and-reliability-of-circuit-breaker-protection.html