Wednesday, February 19, 2014

Welding standards (ISO)

  February 19, 2014 Blogger   No comments

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               Welded, brazed and soldered joints - symbolic representation on drawings (1992)

ISO 2560               Welding consumables. Covered electrodes for manual metal arc welding of non-alloy and fine grain steels. Classification

ISO 3580               Covered electrodes for manual arc welding of creep-resisting steels - Code of symbols for identification

ISO 3581               Covered electrodes for manual arc welding of stainless and other similar high alloy steels - Code of symbols for identification

ISO 3834               Quality requirements for fusion welding of metallic materials, five parts.

ISO 4063               Welding and allied processes - Nomenclature of processes and reference numbers

ISO 5817               Welding. Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding excluded). Quality levels for imperfections

ISO 6520-1           Welding and allied processes — Classification of geometric imperfections in metallic materials — Part 1: Fusion welding

ISO 6520-2           Welding and allied processes — Classification of geometric imperfections in metallic materials — Part 2: Welding with pressure

ISO 6947               Welds. Working positions. Definitions of angles of slope and rotation

ISO 9606               Qualification test of welders — Fusion welding, parts 1 to 5

ISO 9692-1           Welding and allied processes. Recommendations for joint preparation. Manual metal-arc welding, gas-shielded metal-arc welding, gas welding, TIG welding and beam welding of steels

ISO 9692-2           Welding and allied processes. Joint preparation. Submerged arc welding of steels

ISO 9692-3           Welding and allied processes. Joint preparation. Part 3: TIG and MIG welding of aluminium and its alloys

ISO 13847            Petroleum and natural gas industries - Pipeline transportation systems - Welding of pipelines

ISO 13916            Welding - Guidance on the measurement of preheating temperature, interpass temperature and preheat mainteanance temperature

ISO 13918            Welding - Studs and ceramic ferrules for arc stud welding

ISO 13919-1        Welding - Electron and laser-beam welded joints - Guidance on quality level for imperfections - Part 1: Steel

ISO 13919-2        Welding - Electron and laser-beam welded joints - Guidance on quality level for imperfections - Part 2: Aluminium and its weldable alloys

ISO 13920            Welding - General tolerances for welded constructions - Dimensions for lengths and angles - Shape and position

ISO 14112            Gas welding equipment - Small kits for gas brazing and welding

ISO 14175            Welding consumables — Gases and gas mixtures for fusion welding and allied processes. Replaced EN 439:1994 in Europe.

ISO 14341            Welding consumables. Wire electrodes and deposits for gas shielded metal arc welding of non alloy and fine grain steels. Classification

ISO 14554            Resistance welding

ISO 14744            Electron beam welding, six parts

ISO 15607            Specification and qualification of welding procedures for metallic materials - General rules

ISO/TR 15608     Welding - Guidelines for a metallic material grouping system

ISO 15609            Specification and qualification of welding procedures for metallic materials - Welding procedure specification, five parts.

ISO 15610            Specification and qualification of welding procedures for metallic materials — Qualification based on tested welding consumables

ISO 15611            Specification and qualification of welding procedures for metallic materials — Qualification based on previous welding experience

ISO 15612            Specification and qualification of welding procedures for metallic materials — Qualification by adoption of a standard welding procedure

ISO 15613            Specification and qualification of welding procedures for metallic materials — Qualification based on pre-production welding test

ISO 15614            Specification and qualification of welding procedures for metallic materials - Welding procedure test, 13 parts.

ISO 15615            Gas welding equipment. Acetylene manifold systems for welding, cutting and allied processes. Safety requirements in high-pressure devices

ISO 15618-1        Qualification testing of welders for under-water welding. Diver-welders for hyperbaric wet welding

ISO 15618-2        Qualification testing of welders for under-water welding. Diver-welders and welding operators for hyperbaric dry welding

ISO 17635            Non-destructive testing of welds. General rules for metallic materials

ISO/TR 20172     Welding — Grouping systems for materials — European materials

ISO/TR 20173     Welding — Grouping systems for materials — American materials

ISO/TR 20174     Welding — Grouping systems for materials — Japanese materials

ISO 24394            Welding for aerospace applications. Qualification test for welders and welding operators. Fusion welding of metallic components

Saturday, February 15, 2014

Thursday, February 13, 2014

Electrical Switchboard Routine Tests

  February 13, 2014 Blogger   No comments

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

·         General layout of the panel.

·         Check whether all the components are fitted.

·         Check for the Labels and nomenclature

·         Size of Bus bars

Dimensional Check

·         Over all dimensions with approved drawings.

·         List of components its layouts

·         Labels descriptions

Wiring and Control Circuit Check

·         Instrument panel wiring.

·         Control circuit wiring.

·         Power wiring.

·         Protective circuits

·         Rating of breakers

·         Rated voltage of all components

·         Rating of Fuses

Mechanical Operations

·         ON/OFF operations of the circuit breakers by manually.

·         Draw out operations of the withdrawable breakers

·         Breaker interlocking mechanism

·         Electronic protection device of the breakers

·         Operations of the control components like control switches, limit switches etc.

·         Operations of the door interlocking mechanism.

Electrical Operations

·         Electrical ON/OFF operations of the circuit breakers.

·         Electrical functioning of Starters.

·         Operations of components, contactors, control relays, push buttons, indications lamps etc.

·         Checking of electrical interlocking and sequences.

·         Checking of instruments

·         Checking additional protection relays as Ground Fault & Earth Leakage

Torque Test

·         Check all joints of electrical current carrying parts to ensure the tightness by torque range

·         Bus bar joints

·         Breaker terminals

Insulation Resistance Test

·         To check the protective measure of the insulation value

·         To check the continuity of the circuits.

Dielectric Test

Dielectric Test is conducted as per IEC on the power circuits (excluding controls, instruments and electronic components etc.) The test voltage 2.5KV is applied for a period of 1 min. in between

·         1. Phase and phase

·         2. Phase and neutral

·         3. Phase, neutral and earth

 

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

  February 13, 2014 Blogger   1 comment

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 standards covers the following several low-voltage devices including circuit breaker panelboards, switchboards and switchgear, and motor control centers. Although these devices are different in function, the inspection, reconditioning, and testing of all of these devices have enough in common that PEARL believes in appropriate to group them together under section 1300.

Test Equipment:
The following test equipment is required to perform the testing portion PEARL standards related to low voltage circuit breakers:

  1. Insulation Resistance Test Set (Megohmeter) 1000 Vdc minimum
  2. High Current Test Set

One of the following pieces of test equipment may be required to perform the testing requirements of this reconditioning standard:

  1. AC Voltage Supply
  2. AC Current Supply
  3. AC 3-Phase Voltage Supply
  4. DC Voltage Supply
  5. Digital Low Resistance Ohmmeter (DLRO - 10 amp unit is sufficient.)
  6. DC Current Source and a Millivoltmeter

Test Reference Tables:
To adequately test the electrical properties of the switchgear, panelboards or switchboards, you will also need the following technical reference documents, which can be found in the PEARL Reconditioning Standards:

  1. US Standard bus connection bolt torque values (PEARL Reconditioning Standard 6001, Table 1)
  2. Insulation resistance and test values for electrical apparatus (PEARL Reconditioning Standard 6002, Table 2)
  3. Insulation resistance and test temperature conversion to 20°C value (PEARL Reconditioning Standard 6011, Table 11)

Testing TIPS:

  • Panelboards are tested very much like a disconnect switches are tested, including the test of resistance along current carrying path.
  • It is very that the insulation between the current carriers and enclosure is solid and that nothing is escaping to a ground outside the carrying path.
  • Don't trust visual inspection as the sole inspection of insulation; a shaving, or crack in a fiberglass or epoxy insulator that is hidden from view can result in a short circuit and leave users exposed to danger.
  • Occasionally, new replacement insulators can have hidden cracks, resulting in hours of troubleshooting of a completed panelboard or switchgear. It is prudent to test replacement insulators before installation.
  • For motor controls, test each component and subassembly, including transformers, circuit breakers, magnetic contactors, and starters, which can also include integral overload devices that require testing.

Copyright :

http://www.pearl1.org/electrical-testing-tips/electrical-testing-of-low-voltage-switchgear-panelboards-switchboards_TIPS-1300.htm

 

 

Wednesday, February 12, 2014

Wednesday, February 5, 2014

IP69K

  February 05, 2014 Blogger   No comments

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 of 14–16 L/min. The nozzle is held 10–15 cm from the tested device at angles of 0°, 30°, 60° and 90° for 30 seconds each. The test device sits on a turntable that rotates once every 12 seconds (5 rpm).

The IP69K test specification was initially developed for road vehicles, especially those that need regular intensive cleaning (dump trucks, cement mixers, etc.), but it also finds use in other areas

(for example, food industry, and car wash centers).

Saturday, January 25, 2014

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