Rated current (In) value of current, declared by the ASSEMBLY manufacturer taking into consideration the ratings of the components, their disposition and application, which can be carried without the temperature-rise of various parts of the ASSEMBLY exceeding specified limits under specified conditions Rated peak withstand current (Ipk) value of peak short-circuit...
Monday, July 30, 2012
Friday, July 27, 2012
Voltage ratings
Rated voltage (Un) (of the ASSEMBLY) The ASSEMBLY manufacturer shall state the rated voltage(s) necessary for correct functioning of the ASSEMBLY. Rated operational voltage (Ue) (of a circuit of an ASSEMBLY) If different from the rated voltage of the ASSEMBLY, the ASSEMBLY manufacturer shall state the appropriate rated operational voltage of the circuit....
Thursday, July 26, 2012
Electrical checks
Functional tests consist in checking the correct functioning of all the circuits (electrical and electromechanical) by simulating, as far as possible, the different service conditions of the assembly. For example, tests on current and voltage circuits can be carried out by supplying the secondary circuits of the CTs and VTs, without disconnecting the CTs from the circuit....
Mechanical checks
They shall be carried out complying with the relevant documents, making reference to the following specifications: - correct assembling of the equipment (connections and, on a random basis, proper tightening of the connections); - positioning and tightening of nuts and bolts; - mechanical locks and controls (rack-in locking devices, mechanical interlocks, key interlocks...
Wednesday, July 25, 2012
Further checks during testing
Visual inspections They are carried out visually taking into account: a) compliance of the assembly with diagrams, designations, drawings and type of enclosures, number and characteristics of equipment, cross-sectional area of conductors and presence of identification marks on cables and devices (initialing, inscriptions on plates, etc.); b) presence of components...
Routine verifications in compliance with
Routine verifications represent the final technical intervention of the assembly manufacturer before the delivery of the switchgear assembly completed and before invoicing and shipment to the customer. The Standard describes the verifications in the following order: - Degree of protection IP provided by an assembly enclosure It represents the first routine test prescribed...
Protection against direct contact
Protection against direct contact can be obtained both by means of the assembly construction itself as well as by means of complementary measures to be used during installation. The protective measures against direct contact are: - Protection by insulation of live parts Live parts shall be completely covered with an insulation which can only be removed by destruction....
Classification of assemblies
Assemblies may be classified according to different Factors : by the constructional typology, by the external design, by the installation conditions, by the function carried out. Open-type and enclosed assemblies According to the constructional typology the Standard IEC 61439-1 distinguishes between open-type and enclosed assemblies. - Enclosed...
UL Standards (Electrical enclosures)
Industrial Control Panel Enclosures
Products Listed under this category include enclosures that are intended to house open type industrial control panels.
The basic standards used to investigate this category is UL 508A, the Standard of Safety for Industrial Control Panels, UL 508, the Standard of Safety for Industrial Control Equipment, and UL 50, the Standard of Safety for Enclosures for Electrical...
Tuesday, October 19, 2010
Air Circuit Breakers
Earthing System
Earthing System Panel boards are selling several Countries then earthing systems and main Bus bar arrangement are changed each country. Type of System Earthing 01. TN system: TN power system have one point directly earthed, the exposed conductive parts of the installation being connected to that point by protective conductors. Three types of TN systems are recognized, according to the...
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