Thursday, February 27, 2014

Tuesday, February 25, 2014

Terms AC1 and AC3

AC-1 - This category applies to all AC loads where the power factor is more than 0.95. These are primarily non-inductive or slightly inductive loads, such as heating. Breaking the arc remains easy with minimal arcing and contact wear.   AC-3 - This category applies to squirrel cage motors with breaking during normal running of the motor. On closing, the contactor makes the inrush...

Monday, February 24, 2014

Thursday, February 20, 2014

Understanding Type 2 Coordinated Protection in Motor Branch Circuits

The new IEC (International Electrotechnical Commission) standard, publication 947 “Low Voltage Switchgear and Control, Part 4-1: Contactors and Motor Starters,” has been recognized by UL (Underwriters Laboratories) and is becoming widely accepted by designers and users of motor control in the U.S. This standard addresses coordination between the branch circuit protective device...

Why Are Copper Bus Bars Plated?

Even though copper is the most popular choice for use in bus bars, and used very often in other electrical applications because it is more resistant to rust and corrosion than other metals, this doesn’t mean that it won’t oxidize over time.   When metals oxidize, the resistance in the conductive metal will increase, requiring more power to be used to carry current along the surface....

Wednesday, February 19, 2014

CE marking

  The CE marking indicates a product’s compliance with EU legislation and so enables the free movement of products within the European market. By affixing the CE marking to a product, a manufacturer declares, on his sole responsibility, that the product meets all the legal requirements...

IEC 60364 Electrical Installations for Buildings

IEC 60364 Electrical Installations for Buildings is the International Electro technical Commission's international standard on electrical installations of buildings. This standard is an attempt to harmonize national wiring standards in an IEC standard. The latest versions of many European wiring regulations (e.g., BS 7671 in the UK) follow the section structure of IEC 60364 very closely,...

Welding standards (ISO)

International Organization for Standardization (ISO) has developed over 18500 standards and over 1100 new standards are published every year. The following is a partial list of the standards specific to welding: Standard Number            Description ISO 2553              ...

Saturday, February 15, 2014

Thursday, February 13, 2014

Electrical Switchboard Routine Tests

Physical Check ·         Visual check for any physical damages on the enclosures, paint removal and breakage on components ·         Paint shade as per the approved drawings. ·         Cable feeding provisions ·        ...

Electrical Testing of Low Voltage Switchgear, Panelboards & Switchboards (PEARL)

This "How To" electrical testing document is based on PEARL Reconditioning Standard Section 1300, Revision 5 Low Voltage Panelboards, Switchboards & Switchgear, and discusses relevant test equipment as well as suggested procedures and practices to ensure the quality, safety, and speed of your test-for-reconditioning practices. Introduction: The section of the PEARL Reconditioning...

Wednesday, February 12, 2014

Wednesday, February 5, 2014

IP69K

German standard DIN 40050-9 extends the IEC 60529 rating system described above with an IP69K rating for high-pressure, high-temperature wash-down applications. Such enclosures must not only be dust-tight (IP6X), but it must also able to withstand high-pressure and steam cleaning. The test specifies a spray nozzle that is fed with 80 °C water at 8–10 MPa (80–100 bar) and a flow rate...