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.

 

 

Control circuits used in commercial and industrial applications tend to be more complex than this simple circuit and employ a broader variety of components. However, the function of these circuits is often the same, to turn something on and off. In some cases, manual control is used. More often, automatic control circuits or circuits that combine manual and automatic control are used.

 

 

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

                             conductivity caused by condensation may be expected.

Pollution degree 3 : Conductive pollution occurs, or dry, non-conductive pollution occurs which becomes

                             conductive due to condensation.

Pollution degree 4 : The pollution generates persistent conductivity caused, for instance, by conductive dust or by

                             rain or snow.

 

Unless advised otherwise, the Standard and the manufacturer will assume

pollution degree 3 is applicable for industrial applications.

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 at the

manufacturer’s premises, and are:

• part of the quality control activity. They are intended to ensure materials and

workmanship included in every assembly produced meet the standards required

by the design.

• carried out on every assembly or transportable unit to be put into service. It is

recognized that it is unnecessary, with modern modular designs, to fully couple

assemblies for routine test, if they are subsequently to be shipped in several

sections.

• of a non-destructive nature having minimal effect on the service life of the

equipment.

• not intended to duplicate routine tests, previously carried out on components as

part of their manufacturing process.

• not intended to be repeated on site. This does not remove the onus of the

installer to ensure the assembly’s correct installation and obligation to test under

BS 7671. Before tests under BS 7671, or other testing is undertaken, the effects

of these tests on voltage sensitive components should be established.

 

(BEAMA Installation)