Thursday, March 27, 2014

Wednesday, March 26, 2014

Monday, March 17, 2014

Wednesday, March 12, 2014

Choice of a circuit-breaker

Choice of a circuit-breaker   The choice of a CB is made in terms of:   ·         Electrical characteristics of the installation for which the CB is intended ·         Its eventual environment: ambient temperature, in a kiosk or switchboard enclosure, climatic conditions, etc. ·        ...

Low Voltage Circuit Breakers

Based on IEC 60947-2 (LV switchgear and controlgear - Part 2: Circuit breakers):   In (Rated current)   The rated continuous / uninterrupted current that the circuit breaker can carry.   Icm (Rated short-circuit making current)   The short-circuit current that the circuit breaker can withstand as it is closing where the act of closing initiates the...

Tuesday, March 11, 2014

Enclosure Powder coating RAL codes & chart

RAL is a colour matching system used in Europe. In colloquial speech RAL refers to the RAL Classic system, mainly used for varnish and powder coating but nowadays there are reference panels for plastics as well. Approved RAL products are provided with a hologram as of early 2013 to make unauthorised...

Tuesday, March 4, 2014

Determining Temperature Rise

The temperature rise inside a sealed cabinet without forced ventilation can be approximated as follows. First calculate the surface area of the enclosure and, from the expected heat load and the surface area, determine the heat input power in watts/ft.2   Then the expected temperature rise can be read from the Sealed Enclosure Temperature Rise graph. Find where the input...

Heat Dissipation in sealed electrical enclosures

heaT DissipaTion in sealeD elecTrical enclosures The accumulation of heat in an enclosure is potentially damaging to electrical and electronic devices. Overheating can shorten the life expectancy of costly electrical components or lead to catastrophic failure. enclosure maTerials The following discussion applies to gasketed and unventilated enclosures. Higher temperature rises...

Thursday, February 27, 2014