# Frequent question: What is derating factor in motor?

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In electronics, derating (or de-rating) is the operation of a device at less than its rated maximum capability in order to prolong its life. Typical examples include operation below the maximum power rating, current rating, or voltage rating.

## What does derating a motor mean?

Engine derating is the reduction of an engine’s output due to less-than-ideal operating conditions. Derating sometimes is done intentionally when you want to prolong the engine’s life and avoid substantial wear or damage.

## What is the meaning of derating factor?

The derating factor is applied to reduce the cable’s current carrying capacity. For example, if a X-90 cable can carry 40A @90 degrees, there may be additional factors which requires the cable to be de-rated such that it carries only 30A@90 degrees in the installation.

## How is motor derating factor calculated?

New derated torque = Specified torque x √1 – (Ambient temperature – 40) / 100 For example with an ambient temperature of 76°C the new derated torque will be 0.8 x specified torque. Mounting arrangements The motor torque must be derated if the motor mounting surface is heated from an external source, such as a gearbox.

## How do you derate an electric motor?

Therefore, you derate the motor by (1 Hp × (70°C ÷ 82.6°C)2), to 0.72 Hp.

The six times to derate your motor to save its life: Part 1

1. Hot ambient temperature.
2. High elevation.
3. Heated mounting.
4. Power quality problems.
5. Low-speed operations.
6. High-speed VFD switching frequency.

## How do you use derating factor?

Multiply the conductor’s ampacity by the derating percentage. For example: The 12 gauge wire TW wire in the 52 C attic is derated to 76 percent of its maximum ampacity; 25 amperes x . 82 = 19 amperes. Protect the wire with a circuit breaker rated at 19 amps or less.

## What is the importance of derating?

Derating increases the margin of safety between part design limits and applied stresses, thereby providing extra protection for the part. By applying derating in an electrical or electronic component, its degradation rate is reduced. The reliability and life expectancy are improved.

## What is derating of capacitor?

Recommendation for voltage derating means that the actual capacitor shall be used in the application at lower voltage than rated voltage. Derating is expressed usually by percentage of rated voltage that shall be subtracted. … The purpose of the derating is to reduce amount of load accelerating factors to the capacitors.

## What is derating why it is necessary it is same for all means for drives motors and cables?

Derating is a relative term. for cables ,drives and motors it is nomally related with term currrent w.r.to temperature etc. This data/details if given correctly allows user to use the same device with different rating(most of the times lower than rated) without having trouble to change it.

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## What is temperature derating factor?

A specification showing how a rating stated at a particular temperature is reduced at higher temperatures. NOTE 1 Derating is usually expressed graphically or in terms of derating factors (e.g., mA/°C or mW/°C). Peak pulse power ratings may exceed zero at the maximum-rated junction temperature. …

## How is cable derating factor calculated?

cm/watt and laying depth is 1.5 m. Then the cable ampacity should be multiplied by three correction factors. One is laying depth, the second is the soil temperature and the third is soil resistivity. Total derating factor = 0.95*0.9*0.91 =0.77, Then multiply this value by the cable current.