HOW TO DETERMINE THE SIZE OF WIRES FOR SPECIAL PURPOSE OUTLETS

How To Determine The Size Of Wires For Special Purpose Outlets

Here is another concern I frequently hear from an online group of electricians. I understand that some of them are new, and others are in the group to learn. In most cases, special-purpose outlets are those that consist of loads like the water heater, electric ranges, refrigerators, and home appliances that have higher loads and are usually fixed in their locations.

In this case, we only cover non-complicated and individual appliances for the sake of first-hand ideas or knowledge in this regard. The very first thing to put in mind is that the size of wire or cable to be used must be able to carry the current drawn by the utilization equipment or load. The circuit breaker must also coincide with the wire or cable rating to ensure safety.

The best reference in determining the size of wire or cable, including the size of the circuit breaker protection of the unit is the equipment's nameplate rating usually placed at the back of the equipment's body or enclosure. Usually, what is given are the voltage, current, wattage, frequency rating, and the phasing. Knowing the wattage or current rating, you are given the idea and you can come up with the proper size of wire and its circuit breaker protection.

Fig. 1. Mini Ref

                                                    

Fig. 1 Photo shows a sample specification rating at the upper right corner of a mini-refrigerator. 

 Fig. 2. Mini Ref 

                                                             

Fig. 2 Enlarged photo of the sample specification rating at the upper right corner of a mini-refrigerator.

Only, you should always remember that the current ampacity rating of the wire to be used shall, in no way, be lesser than the current rating of the equipment serve, There are also other technical considerations that have to be considered when coming up with the proper sizing of circuit wires and circuit breaker protection. Continuous loads, motors loads, the distance of the load or equipment served, and others. I will be discussing them next as I go on with my blog.