How do I choose a cable size for a specific load?

Full Load Current = (KVA · 1000) / (1.732 · Voltage): Full Load Current = (100 · 1000) / (1.732 · 415) = 139 Amp….Let’s select 3.5 core 95 Sq.mm cable for single run, short circuit capacity = 8.2 KA.

Current capacity of 95 Sq.mm cable is 200 Amp,
Total derating current of 70 Sq.mm Cable = 200 · 0.93 = 187 Amp.

What amps can a 2.5 mm cable take?

A 2.5mm cable is capable of supplying around 23-25 amps depending on the method of installation, so is fine, safe and compliant on a 20amp circuit breaker.

How far can you run 2.5 mm cable?

Yes, you can calculate the maximum length of a circuit for any given situation. A good rule of thumb for ring finals wired in 2.5mm is that the total length of cable used should preferably not exceed 100m.

How to select cable size for various loads with?

To determine cable size keep in mind these rules of voltage drop. For a given load, there should be 20% extra scope of current for additional, emergency or future needs (except the known value of current). From Energy meter to DB, voltage drop should be 1.25% and 2.5% for final sub-circuit should not exceed 2.5% of Supply voltage.

How to calculate the cable size for a motor?

Hence the cable rating formula can be written as, Cable size = 1.5 x Full Load Current. Let’s we calculate required cable sizing for 5.5kW/7.5HP motor which is operated at 415V, 0.86pf. From our cable size calculator, the full load current of the 5.5kW motor is 10A. Hence, the required cable shall able to carry minimum 15A current.

How to calculate voltage drop and size of electrical cable?

Calculating Correction Factor of Cable from following data: – Total derating factor = 0.93 Cable derating amp should be higher than full load current of load. Cable voltage drop should be less than defined voltage drop. No. of cable runs ≥ (Full load current / Cable derating current).

How big of a cable do I need for single phase?

The cable size chart is suitable for both single-phase and three-phase. Note: using larger size cable is not recommended.