# Best answer: How do you calculate the cable size of an HP motor?

Contents

The cable size is equal to the 1.5 times of the full load current of the motor/load. Hence the cable rating formula can be written as, Cable size = 1.5 x Full Load Current.

## What is the formula for calculating cable size?

Current rating for 40°C (104°F) = 23 x 0.97 = 22.31 Amp. Since the calculated value (22.31 Amp) at 35°C (95°F) is less than that of current carrying capacity of (7/0.036) cable which is 23A, therefore this size of cable (7/0.036) is also suitable with respect to temperature.

## How do I choose a cable for my motor?

Size of Cable for Branch circuit which has Single Motor connection is 125% of Motor Full Load Current Capacity. Example: what is the minimum rating in amperes for Cables supplying 1 No of 5 hp, 415-volt, 3-phase motor at 0.8 Power Factor. Full-load currents for 5 hp = 7Amp. Min Capacity of Cable= (7X125%) =8.75 Amp.

## What is the cable size for 90 KW motor?

Cable Size Calculation of 90 Kw LT Motor

in ideal case 157 amp shall be current capacity of cable and if we look at the cable size chart we will find that for 157 amp the current rating cable size 70mm2 cable size would be perfect.

## How do I choose a power cable?

Cable size selection is based on three main factors:

1. Current carrying capacity.
2. Voltage regulation.
3. Short circuit rating.

## How do I calculate motor cable size?

The cable size is equal to the 1.5 times of the full load current of the motor/load. Hence the cable rating formula can be written as, Cable size = 1.5 x Full Load Current.

## How do you calculate current cable capacity?

Cable Capacity

For Cable Current Capacity = 4X Size of Cable in Sq.mm, Ex. For 2.5 Sq.mm = 4×2.5 = 9 Amp.

## What is the size of cable?

Cable Size & Current Rating Chart

Cross Section (mm2) Approximate Overall Diameter (mm) Current Rating
25 8.7 101
35 10.08 125
50 11.8 151
70 13.5 192

## How do I choose cable size from KW?

Full Load Current = (KVA · 1000) / (1.732 · Voltage): Full Load Current = (100 · 1000) / (1.732 · 415) = 139 Amp.

Let’s select 3.5 core 70 Sq.mm cable for single run.

1. Current capacity of 70 Sq.mm cable is: 170 Amp, …
2. Total derating current of 70 Sq.mm cable = 170 · 0.93 = 159 Amp.

## What size wire do I need for a 10 hp motor?

Womack Data Sheet 78: Wire Size and Fuse Ratings for 3-Phase Induction Motors

HP Speed RPM 230-Volt Service
7-1/2 1,800 40
7-1/2 3,600 40
10 1,200 60
10 1,800 60