Motor Specifications – Voltage,Ampere and Frequency

These parameters are important to clarify our application design from voltage value,phases,full load ampere, overload setting and frequency setting if using Variable Speed Drive.

As an electrician,we must fully understand what is mean by voltage, ampere and frequency to ensure our application safe and working properly.

Ok…let we start our discussion and explanation about Voltage, Ampere and Frequency on Electric Motor Nameplate.


What is Rated Voltage?For simple understanding, rated voltage is manufacturer design for suitable operated voltage value with optimal performance.We can refer the motor voltage and phases on the nameplate also can decide either voltage/phases is available in our installation or not.Every country have different value of voltage.Please make sure your motor are followed standard country voltage. Read More

General Requirement For Circuit Breaker

Circuit protection is a mandatory items that we MUST consider carefully for Electrical Installation project.I will take a fully attention during sizing and follow standard requirement for circuit breaker.

If the circuit protection not function properly, it’s can cause a serious damage to equipment and personnel.On my last post,I had discussed about Circuit Breaker Sizing.

This time I want to share some information about general requirement for circuit breaker that commonly apply for Electrical Installation project.I hope this post can help to have a basic guideline during handle any project of electrical installation. read more

Electrical Cable/Wire General Requirement

This topics always discussed among of electrician personnel that involved on new installation or electrical projects.If they miss calculated or choose a wrong size for the conductor/wires,it’s can cause a big disaster when that installation failure.

Electrical cable/wire is a important things that we must consider with calculation and detail discussion to avoid any mistaken during design and installation.We must take a serious action to get a good result.

I would like to shared some general requirement for electrical cable/wire for new electrical installation or projects that we must consider during design review.I hope this can make a guide line for the best result in your installation or projects. read more

Electrical Conduit

What is a conduit?For an electrician work scope,conduit is a one of famous method for electrical cable route wiring in domestic or industrial sector.

A conduit is a channel or pipe that electrical cable are contained secure inside when do the electrical wiring.We can route the conduit at the surface or con-seal method.

The main purpose of conduit application are to providing a mechanical protection of electrical cable,easy for rewired or modification of circuit,flexibility and look tidy installation.Normally we can found several types material of conduit and it made for different application and condition such as PVC,Steel,Stainless Steel & Flexible.

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NEC calculation for overload sizing

Sizing for overload is important to avoid serious damage for electrical application such as motor starter,machinery or others electrical equipment.

According to NEC,the general requirement for overload sizing be set around 115% or 125% from full load ampere.We should setting the overload relay within this parameter to avoid electric motor from serious damage.

For calculation of overload sizing,it depend on the motor full load ampere current rating,the service factor and temperature for motor.I already explain in my last post about several factor effected for overload relay sizing. read more

Motor start and run capacitor

Application of start and run capacitor for single phase motor.

Why we applied a capacitor for single phase induction motor?The reason is to improve performance of motor by generate the rotating field.Design for this motor have a two ( 2 ) stator winding,and one of it is the auxiliary and is connected by a suitable capacitor size.

The capacitor increases the starting torque and the full load power as the current flowing through the auxiliary winding, de-phased by the capacitor, creates a rotating field.The voltage across capacitor usually higher than the mains supply.

The choice of the capacitance is usually empirically made on the motor. This is because of shuttle differences between motor manufacturers.As the torque and the power of the motor also depends on the reactive power of the capacitor. read more

Single phase capacitor

Firstly let me describe about what is capacitor?This device is very common used in electronic and electric application.The main function is to stored and release electricity charge.

It charge and release depend on frequency ( Hz ) of our power supply.Normally around 50 until 60 times per second in alternating current system.

The construction of capacitor basically made from wound layers of metalized polypropylene (dielectric).The element is sealing in a plastic can with a suitable sealing material.

We can see a two metal plates insulated from each others.For oil filled type,it use a PCB`s as a coolant agent,but now almost capacitor is dry type. read more