kallen88
Electrical
- Apr 10, 2013
- 25
Hello all,
I need a bit of guidance in relation to the design and specification of components and cables for a process control panel. My technical studies are in mechatronic engineering and have mainly been involved in instrumentation and programming PLCs at my work place so far. I have been asked to provide a design for the refurbishment of an outdated control panel for a piece of processing plant on our site. I need to fully spec the power requirements and protection for equipment including DOL and VFD operated motors, de-magnetisation equipment and other monitoring instrumentation.
So my dilemma starts with how to determine the ratings and locations of protection equipment such and breakers, RCDs and overload protection. I do not have anything to do with the power distribution around our site but I want to know if I need to consider things like the short circuit capabilities of the distribution system, any up stream protection devices and the earthing system of the distribution network in order to specify the protection devices. I am in Australia so the supply is 415V 3 phase from one of our distribution panels.
I have been using the relevant Australian Standards to try and work out cable sizing and protection components and have come across things such as protection coordination which i'm not sure if I need to consider. As far a specifying cables, I understand that short circuit protection needs to be designed such that during fault conditions the cable will need to withstand the amount of fault current for the duration of time it takes the fault to clear. However I do not know what this fault current is except that the breakers on the panel are rated to 6kA and our electrical contractor could not give me an exact figure either. Should I just use the 6kA for the cable calculations or try to obtain this information.
Sorry for the novel, i'm just a bit out of my field of experience and need some guidance.
Cheers,
Kallen.
I need a bit of guidance in relation to the design and specification of components and cables for a process control panel. My technical studies are in mechatronic engineering and have mainly been involved in instrumentation and programming PLCs at my work place so far. I have been asked to provide a design for the refurbishment of an outdated control panel for a piece of processing plant on our site. I need to fully spec the power requirements and protection for equipment including DOL and VFD operated motors, de-magnetisation equipment and other monitoring instrumentation.
So my dilemma starts with how to determine the ratings and locations of protection equipment such and breakers, RCDs and overload protection. I do not have anything to do with the power distribution around our site but I want to know if I need to consider things like the short circuit capabilities of the distribution system, any up stream protection devices and the earthing system of the distribution network in order to specify the protection devices. I am in Australia so the supply is 415V 3 phase from one of our distribution panels.
I have been using the relevant Australian Standards to try and work out cable sizing and protection components and have come across things such as protection coordination which i'm not sure if I need to consider. As far a specifying cables, I understand that short circuit protection needs to be designed such that during fault conditions the cable will need to withstand the amount of fault current for the duration of time it takes the fault to clear. However I do not know what this fault current is except that the breakers on the panel are rated to 6kA and our electrical contractor could not give me an exact figure either. Should I just use the 6kA for the cable calculations or try to obtain this information.
Sorry for the novel, i'm just a bit out of my field of experience and need some guidance.
Cheers,
Kallen.
