Gap Between Load and Capacity

I strongly suggest that you enroll here. The life you save may be your own. Study Electrical Engineering in Pakistan, Electrical ...

Dear lyn,

why you suggest me that site. i m not an electrical engineer, and i also have not much knowledge like u, but i want to learned as much as possible about my field. may be i asked stupid question,s but these are confusion,s in my mind which i want to clear. and i m not in Pakistan, i m in Abu Dhabi, employee in a company. so i cannot goes to any engineering university, just try to get knowledge forum or site like this. if u can help me thank,s. if u cannot then also thank,s to you.

Regard,s.

I'm tempted to say something like a quarter of an inch.

Hire a qualified Electrical Engineer, who will use the local equivalent of British Standard 7671.

dear pwslack,

all of you are qualified electrical engineer,s and i cannot hire any electrical engineer that,s why i ask question,s to you.

Regard,s.

some folks have had too much coffee...

for the "el" of elcb, i suspect that 30mA is appropriate.

but...

let us look at some scenarios, based on australian circuits. lighting circuits are protected by a 10 amp breaker, and use 1.5mm cable. standard "10amp" power circuits are protected by a 16 amp circuit breaker with 30mA earth leakage protection and use 2.5mm cable. 15 Amp power circuits are typically run with 4mm cable and protected by a 20 amp circuit breaker. remember one breaker/elcb/rcd per circuit and it is the cable that you need to protect with the amperage of the circuit breaker. circuit breakers protect property, RCDs protect people. so it is not a matter of "gap" but a consideration of the cable's current carrying capacity (for this try googling olex cable catalogue). and don't forget to consult your applicable wiring regulations for loading, how many power points on one circuit using a certain cable size.

still, it is not that simple (eg: fixed single phase aircon in domestic house or unit over 10 amps should have circuit breaker rated at less than 75% of full load in accordance with AS/NZS 3000:2007), and you will be legally liable if your installation kills or injures somebody. so at the end of the day, hire a licenced and competent professional.

i hope this helps