4.
2. Surrounding temperature: cable resistance increases temperature
increases and insulation may melt the temperature too high.9V for
lighting and 11. They are also given Table 14.65A may used safely rather
than 52.5V for other uses 230V installation.
The cable rating, denoted It, may determined follows:
It
Current rating protective device
Any applicable corre
c
ction factors
. Where two cooking appliances
are installed one room, such split-level cookers, one switch may be
used control both appliances provided that neither appliance more
than from the switch (On Site Guide, Appendix 8). Type protection: for how long will the cable have carry fault
current?
Regulation 525 states that the drop voltage from the supply terminals to
the fixed current-using equipment must not exceed for lighting circuits
and for other uses the mains voltage.17A cable. Design current: cable must carry the full load current.
3.Basic Electrical Installation Work
298
Therefore, cable capable carrying 27.
Conductor size calculations
The size cable used for installation depends upon:
● the current rating the cable under defined installation conditions
and
● the maximum permitted drop voltage defined Regulation
525. Type cable: PVC, MICC, copper conductors aluminium
conductors.
The factors which influence the current rating are:
1. The volt drop for a
particular cable may found from:
VD
Factor Design current Length run
The factor given the tables Appendix the IEE Regulations and
Appendix the Site Guide. Installed conditions: clipped surface installed with other
cables trunking.
A cooking appliance must controlled switch separate from the
cooker but readily accessible position. That maximum 6.
5.3
