Saturday, February 17, 2018

Today I am sharing staircase timer wiring diagram. In this post you will complete learn how to use a on delay timer as staircase timer with finder 8 pin relay. In the today staircase wiring with timer diagram. I use a on delay timer which mostly use for star delta connection, a 8 pin relay, and push button switches.

Staircase Timer Wiring Diagram - Staircase connection with timer

In the below staircase timer wiring diagram I shown 2 8 pin relay socket, a on daily timer, a 8 pin finder type relay, 2 push button switches, a light bulb and wiring connection.
In the below wiring diagram I shown also the star delta i.c timer wiring diagram. And 8 pin finder relay wiring diagram. In the below wiring connection I use the on delay timer as staircase timer. In the below staircase timer wiring the relay use as holding current device. When someone push the push button the relay the timer and relay operate and light switch on. But when the timer complete the time the timer off the relay and the relay reset the timer. 

So if you want to ON a machine for a specific time then you can use the below connection for motor.

staircase timer wiring diagram

The above staircase wiring with timer diagram is very to understand. However if you have any question then you can use the below comments section. Also read the below post...

Also read:

Why I use 8 pin relay with timer

In the above staircase timer wiring diagram I use the 8 pin finder relay. So I can switch off any device my using the timer than why I use relay in above circuit diagram.

When operate the timer. The timer change the normally close to open circuit in on delay timer but this timer did not switch off himself. In other words the timer did not reset automatically. So in the above case we need to reset timer automatically when the specific timer over. So I use relay as holding current to relay and as reset for timer. 

Now I hope you completely understood that how use a relay as reset switch with timer, and staircase timer wiring diagram. Stay tune with us.... And Take care.

Wednesday, February 14, 2018

Today I am sharing with new the simple and easy 3 phase motor current calculation formula for LT motors. In this post I am sharing with you a nameplate of 3 phase low voltage induction motor. In the name plate all data given my manufacture company.

3 phase motor current calculation formula

3 Phase Motor Current Calculation Formula Explained

In the below image I shown a 3 phase motor nameplate. In the motor name plate the company provide the motor is 15 KW 3 phase induction motor. The Eff of motor is 0.89 and PF is 0.85. The volts of the motor 380V and Amps are 30.1.

So this data is provided by the company. Now first see the image and after that we start doing current calculation of 3 phase motor. That how comply calculate the current of three phase motor and how 30.1 amperes are given in nameplate.

3 phase motor nameplate details

For 3 phase low voltage motor current calculation we need the motor volts, Eff, PF. For three phase motor amps calculation the below formula is used.

3 phase motor current calculation formula is P/(√3xVxPfxEff) or P/(1.732xVxPfxEff) Both are same.

So our motor power is 15KW with 15 x 1000 = 15000 Watts. Motor volts is 380 volts, Eff is 0.89 and PF is 0.85 according the above nameplate.

So if we calculate 15000/(1.732x380x0.85x0.89)

15000/(497.89) So 15000 / 497.89 = 30.12 Amps Or Load current of motor.

By using this formula you can calculate the 3 phase low voltage motor. This is very simple and easy formula.

Also read


I hope this 3 phase motor current calculation formula (how to calculate 3 phase motor current) help you. And know you will be able to calculate the load of 3 phase motor by using the above load current formula. Now if you have any question or want to gave us some suggestion about our blog then you can use the below comment section.