Control Circuits

Control Circuits Control  Control components are used in a wide variety of applications with varying degrees of complexity. One example of a simple control circuit is a circuit that turns a light on and off. In this circuit, the control component is often a single-pole switch.  ...

Electrical Panel

...

Pollution Degree

The level of pollution in the environment in which the Assembly is intended to be installed. Four categories are defined in the Standard as follows:   Pollution degree 1 : No pollution or only dry, non-conductive pollution occurs. Pollution degree 2 : Normally, only non-conductive pollution occurs. Occasionally, however, a temporary                             ...

ROUTINE TESTS

These tests have a totally different function to Type Tests, BS EN 60439-1, states:   ‘Routine tests are intended to detect faults in materials and workmanship. They are carried out on every ASSEMBLY after its assembly or on each transport unit. Another routine test at the place of installation is not required.’   Hence, Routine Tests on Assemblies are normally undertaken...

PARTIALLY TYPE TESTED ASSEMBLY (PTTA)

IEC 60439-1, defines a PTTA as: ‘A low-voltage switchgear and controlgear assembly, containing both type-tested and nontype- tested arrangements provided the latter are derived (e.g. by calculation) from type tested arrangements which have complied with the relevant tests’.   This means: • The assembly will be derived from a Type Tested Assembly. • Deviations...

TYPE TESTED ASSEMBLY (TTA)

IEC 60439-1, defines a TTA as:   ‘A low-voltage switchgear and controlgear assembly conforming to an established type or system without deviations likely to significantly influence the performance, from the typical ASSEMBLY verified to be in accordance with this standard.’   This means: • The generic design of the Assembly including all the various elements...

Current ratings

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...

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....

IEC 61439 series

For the new re-structured IEC 61439 series, the following parts are envisaged: – IEC 61439-1: General rules – IEC...

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...

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...