Monday, December 30, 2013

Friday, December 13, 2013

Dead-front panels

Dead front is defined in Article 100 of the NEC as being “without live parts exposed to a person on the operating side of the equipment.” Section 408.38 requires that panel boards be mounted in cabinets, cutout boxes or enclosures designed for the purpose and shall be dead front. The term “dead front” is used in other places in the NEC, but basically, the NEC requires distribution panels,...

Tuesday, December 10, 2013

Circuit breaker accessories - Service releases

Shunt opening release   This allows circuit-breaker opening by means of an electric command. Release operation is guaranteed for a voltage between 70% and 110% of the rated power supply voltage Un, both in AC and in DC. It is always fitted with an auxiliary limit contact.   Under voltage release   This opens the circuit-breaker due to a power...

Information included in the design verification

The design verification serves to document compliance with the specifications of this standard. It is comprised of 13 individual verifications. For selected individual verifications, additional sub-verifications in subcategories may be required. If selected verifications are not required due to the application, the respective verification should, as a minimum requirement, state...

Tuesday, December 3, 2013

Calculation of the temperature rises in compliance with the Std. IEC 60890

Calculation of the powers generated by the different components and dissipated inside the assembly   The calculation of the power losses reported in the configurations shown is carried out by taking into account the effective powers dissipated by the different components....

Open-type and enclosed assemblies

According to the constructional typology the Standard IEC 61439-1 distinguishes between open-type and enclosed assemblies.   - Enclosed assembly   An assembly is enclosed when there are protected panels on all its sides so as to provide a degree of protection against direct contact not lower than IPXXB (see Chapter 4). Assemblies intended to be installed...

Monday, December 2, 2013

Friday, November 29, 2013

IEC standards

IEC 60038 Standard voltages IEC 60076-2 Power transformers - Temperature rise IEC 60076-3 Power transformers - Insulation levels, dielectric tests and external clearances in air IEC 60076-5 Power transformers - Ability to withstand short-circuit IEC 60076-10 Power transformers - Determination of sound levels IEC 60146 Semiconductor convertors - General requirements and line...

Clearances & Creepage distances for LV panel boards

Clearances distances Shortest distance in the air between two live conductors or between live Conductors and exposed conductive parts. 14 mm for 12 kV impulse voltage 8 mm for 8 kV impulse voltage 5.5 mm for 6 kV impulse voltage The IEC 60439-1 and IEC 61439-2 standards stipulate the minimum clearances Required to withstand impulse voltage up to 2000 m above sea...

MILLIVOLT DROP TEST

The millivolt drop test is generally associated with testing for weld quality on the armature. It is the best test for verifying armature weld quality. The millivolt drop test is the ultimate electrical test for detecting bad welds. Unfortunately, it is difficult to make on armatures with large diameter wire and nearly impossible to make on armatures with small wires....

Saturday, November 9, 2013

The new IEC 61439 standard

The new IEC 61439 standard applies to enclosures for which the rated voltage is under 1000 V AC (at frequencies not exceeding 1000 Hz) or 1500 V DC. The standard defines the design verified ASSEMBLIES and eliminates completely the categories TTA and PTTA. In order to conform to the standard, type tests have been replaced by a design verification which can be carried ...

IEC 60529 First Characteristic Numeral Degrees of Protection - Solids

>> IEC 60529 First Characteristic Numeral Degrees of Protection – Solids   Protection Test Method Pass Criteria   INDOOR   IP 1X Incidental Contact & Solid Objects Ø 50 mm – Probe No Penetration IP 2X Incidental Contact & Solid Objects Ø 12.5 mm – Probe No Penetration IP 3X Incidental Contact & Solid Objects Ø 2.5 mm – Probe No Penetration...

Thursday, October 24, 2013

Saturday, October 19, 2013

Saturday, October 12, 2013

Standard-compliant switchgear and controlgear production (Application of IEC 61439)

  A new standard. A new opportunity. 3 Contents 4 One standard for all switchgear and controlgear assemblies 6 What has changed under the new standard? 8 What does the new standard mean for you? 10 Rittal – The System. Complete solutions – Customised for IEC 61439...

Guide to migration from IEC 60439 to IEC 61439 (XL3 Confugurable Assemblies IEC 60439 >>> IEC 61439)

This document only deals with  distribution enclosures for advanced users (authorised persons), i.e. parts 1 and 2 of the new standard. Part 3 of standard IEC 61439 discusses DBO (Distribution Boards intended to be operated by Ordinary persons) only up to 250 A. One of the new features of...