General Requirement For Motor Starter

When we plan to install new motor starter,we need to consider a few requirement that we want to apply to get a best design,tidy and easy to troubleshooting if have any problem.

Normally motor starter component includes a drive (VFD),electrical wiring,control panel,communication system (Ethernet / Devicenet) and types of starter that we plan to use.

From the design stage,we must follow general requirement for Motor starter to get a best result for our installation.Below I listed some of requirement to build a motor starter.I hope it’s can give a clear view or guide line during design a motor starter. read more

Troubleshooting guide when motor overload trip

On my last post,I’d discussed about motor overload relay that are common used for motor starter application.As we known,the main purpose of motor overload relay is to protect our electric motor winding from mechanical overload that can result the serious damage.

This time I want share basic guideline or troubleshooting method how to troubleshooting when motor overload relay trip.I hope this post can give some ideas or clear view when you face this similar problem during your routine jobs. read more

How to setting the timer for star delta starter?

How many second we need to setting for changeover timer from STAR to DELTA sequence for Star Delta Starter?This question is very popular among electrician around the world when handling the Star Delta Starter for their application.

From my experience,honestly,it quite difficult to get the accurate times for star delta changeover.But we can get the approximate times with several monitoring technique and measuring equipment to decide the best setting for change over timer of Star Delta Starter.From this post,i would like to share some information and basic technique how to get the approximate times for Star Delta Starter change over timer.I hope from this post,it’s can give some ideas or clear view how to setting the times for Star Delta Starter change over timer.

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Motor Protection : Over temperature

Motor temperature is one of the factor that we should monitor and make sure it running in a normal range.It is closely related with winding temperature.If temperature is highly from standard value,it can cause a winding insulator damage or weak.

From that damage,it will make the internal short circuit between winding phase and can cause a serious damage for an electric motor.

What is the main reason for the motor overheat or over temperature?Normally it cause due to a high ambient temperature,under sizing motor capacity,not suitable voltage rated,running in overload and bearing jammed. read more

Motor Protection : Phase failure and reversal

What happen if one of a cable broken or fuse blow while the electric motor is running?The answer is motor will run in two phase supply that can generate the high draw current due to unbalance of phase.

Why the current value increase?From the theory, the current in the two phase would increase by 1.7 times due to negative phase and generate heat in the rotor area.If this situation continue in a long time period,it can cause serious damage.

Another phenomena would happen is the motor are interchanged the motor will reverse its direction of rotation.We called is phase reversal and it can cause serious injury and motor damage. read more

How to change rotation for Star Delta Starter?

Electric motor have a two side of rotation.It is clockwise and anti clockwise or normally we call it forward and reverse rotation.An equipment or machinery that connected to electric motor have a rotation depend on manufacture design and application.

Common rotating equipment that we can found at our surrounding area such as pump,air-compressor,water jet and etc.Normally manufacture put a sign or arrow for rotation to avoid their equipment not install in proper way and can avoid serious damage or malfunction.

During installation and wiring termination,we must check and verify our rotation for equipment either it is forward or reverse rotation to avoid any problem or malfunction after completed installation works. read more

AC motor protection device

As we know,motor protection is one of the important criteria when we involve for AC motor installation,wiring and termination works.Commonly magnetic contactor,fuse, Molded case circuit breaker (MCCB) and overload relays are used for motor control device of induction motor.

In general ideal for motor protection,it have two basic protections always installed for every motor are Over-load protection and Short-circuit protection.For advance protection we can added for protection against unbalanced supply voltages, under voltage, reverse phase, over temperature and stalling etc. read more