So basically, relays (contactors) are used when we do not intend to directly switch OFF/ON high voltage and high current circuits (AC motors)? Because what you are implying is that direct control of high voltage/current circuits pose potential danger to safety of operators? Let's say we have an air handling unit with a single feed electric panel feeding two supply fans (Each with 10HP AC motors). Would a panel disconnect switch still be required if we can use 24 V switch to operate the motor contactors?
You may have misunderstood the premise. High voltage, such as 440VAC that is used to feed a motor circuit, cannot be switched on and off by a pushbutton directly. The pushbutton does not have a power rating sufficient to do that. That would pose a significant safety risk. Instead, we can connect a pushbutton to a relay (motor start relay) that energizes a low-power 24VDC or 120VAC relay that is able to pull in a larger set of contacts (motor starter) to start the motor. To answer your second question, it is good practice (and usually required by local codes) to have a main disconnect for a control panel. Power disconnect switches are able to be de-energized and locked out to prevent safety issues. Relays are also invaluable to keep circuits separated (for example, 24VDC from 440VAC, or two different 24VDC circuits),l also for safety reasons.
Great question! PLC programming with ladder logic has changed very little since PLCs first appeared in the 1970's. The software has improved dramatically as PC's became more powerful, and more graphical. But even more recently, most manufacturers have provided backwards compatibility with their instruction sets. I can upgrade most Siemens S7-300 programs to S7-1500 with not much effort. If you can program an S7-300, you can program an S7-1500, and vice versa. You may need to become familiar with a few differences in the software versions, but that is like learning a new version of Excel. Newer PLC's are faster, have more memory, and can handle more I/O than older PLC's, but they are essentially the same useful logic processors.
I dont mean to be off topic but does anyone know of a way to log back into an Instagram account..? I was stupid lost the account password. I would love any help you can offer me.
@Yahir Avery i really appreciate your reply. I got to the site through google and Im trying it out now. Seems to take a while so I will reply here later when my account password hopefully is recovered.
Hi there, in this video we have simplified the process of turning on and off the headlights of a car as an example for you to get the gist of the relay application. Actually, when you give the command to turn on the headlights in your car, this command goes over to the relevant ECU (which stands for Electronic Control Unit) in the car. ECU itself cannot send the voltage directly to different parts of the car such as the headlights, but instead, it gives the command to the relay which is associated with that part. That means it converts the voltage to the voltage level which is required by the headlight to be turned on.
Just wondering, if the headlight switch in a car is a 12v connection and the headlights circuit is also 12v - why would you need a relay? I have a very basic understanding and I thought relays were used to control hvac circuits with lvdc/ac to prevent serious electric shock?
There are a couple of reasons that a relay is used. The main reason is that with higher-powered headlights, it is necessary to use a relay to separate the low-power switching circuit (what turns your lights on and off) and the higher-power circuit to the lights. Most auto headlight relays have two NO contacts so that both headlamps can be powered from one relay. This allows each headlamp circuit to be individually fused and isolated.
When it's easy to understand, learning is easy. Perfect instructor.
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Hi my friend! Today is the happiest day of my life!!!I became a subscriber to your channel)
That's amazing, great to have you here - enjoy the video courses!
Its very nice, the way to explain the things. its really very good!
Happy to hear that! Thank you.
Your team work is great.thank very much
Thank you so much, Masoud!
Very good video sir
thanks realpars. student from VietNam
Our pleasure!
Hi. Your videos are great. Please make a video about ssr relay and its application in control panels.
Hey Farzad!
Thanks for your comment and your suggestion. I will pass this on to our course developers!
Thanks for sharing and happy learning!
Awesome video! Please make videos more frequently.
Hi Kanav, Thaks for the feedback. We'll send more videos your way soon! :)
thanks for easy explanation.
You're more than welcome!
At RealPars.com you learn more than just programming when you you subscribe to RealPars.com.
I'm eagerly awaiting level 9 videos.
so clear, thanks a lot
You are welcome!
Need more relay videos
thank you very much for your lectures.....very helpful....Your Student From Pakistan
You're very welcome! Glad that you found this helpful.
dude great explanation. gave us the info, gave easy example like the headlights. awesome
Great to hear that! Thank you.
Tooo helpfull well defined about relay
Thank you!
Good explain . 😊
Thank you
You are welcome!
So basically, relays (contactors) are used when we do not intend to directly switch OFF/ON high voltage and high current circuits (AC motors)? Because what you are implying is that direct control of high voltage/current circuits pose potential danger to safety of operators?
Let's say we have an air handling unit with a single feed electric panel feeding two supply fans (Each with 10HP AC motors). Would a panel disconnect switch still be required if we can use 24 V switch to operate the motor contactors?
You may have misunderstood the premise. High voltage, such as 440VAC that is used to feed a motor circuit, cannot be switched on and off by a pushbutton directly. The pushbutton does not have a power rating sufficient to do that. That would pose a significant safety risk. Instead, we can connect a pushbutton to a relay (motor start relay) that energizes a low-power 24VDC or 120VAC relay that is able to pull in a larger set of contacts (motor starter) to start the motor. To answer your second question, it is good practice (and usually required by local codes) to have a main disconnect for a control panel. Power disconnect switches are able to be de-energized and locked out to prevent safety issues. Relays are also invaluable to keep circuits separated (for example, 24VDC from 440VAC, or two different 24VDC circuits),l also for safety reasons.
do generally realys are used for low voltages or high voltages which can be controlled using switches or push buttons
Are older PLC models any different than the ones in your videos?
Great question! PLC programming with ladder logic has changed very little since PLCs first appeared in the 1970's. The software has improved dramatically as PC's became more powerful, and more graphical. But even more recently, most manufacturers have provided backwards compatibility with their instruction sets. I can upgrade most Siemens S7-300 programs to S7-1500 with not much effort. If you can program an S7-300, you can program an S7-1500, and vice versa. You may need to become familiar with a few differences in the software versions, but that is like learning a new version of Excel. Newer PLC's are faster, have more memory, and can handle more I/O than older PLC's, but they are essentially the same useful logic processors.
thank you alot. Keep doing this
Thanks for watching! :)
Awesome but we want to some more about relay
Very useful 👌
Glad to hear that!
Very interesting video , about relay function! Thank you
Thank you, Javier! Happy to hear
I dont mean to be off topic but does anyone know of a way to log back into an Instagram account..?
I was stupid lost the account password. I would love any help you can offer me.
@August Rodrigo Instablaster =)
@Yahir Avery i really appreciate your reply. I got to the site through google and Im trying it out now.
Seems to take a while so I will reply here later when my account password hopefully is recovered.
@Yahir Avery it did the trick and I now got access to my account again. I'm so happy:D
Thank you so much, you saved my account!
Awesome video. Can you do a video on contactor and NO, NC push button switch
Hi Vaishak,
Thanks a lot!
Also, thank you for the topic suggestion, I will definitely go ahead and forward this to our creator team. Happy learning!
Can you pls make one short vdo on the topic of "Potential Free Contact" and "Interrogation Voltage", same shall be explained by circuit diagrams.
Hey!
Thanks for your comment and your suggestion. I will pass this on to our course developers!
Thanks for sharing and happy learning!
Thank you
I have question please? How do you do this wiring?
You're very welcome! I'm sorry I'm not sure if I understand your question. Can you please elaborate?
Thanks for this important clip
Adaa mudan :).
Hey! You're so welcome. :)
Very nice sir
Thank you!
Thanks for the explication. Congratulation
You are very welcome!
What the software that you use to make this awesome animation explanation?
Hi Mu'az,
Thanks for your comment!
I am actually not sure about this as this is done by our graphic and animation department.
@@realpars thanks for your reply..its ok.
@@realpars need more education video like this..
Thank you very much.
You are very welcome!
Why do the headlights on the car have to go through a Relay? Is it also due to higher voltage and safety?
Hi there, in this video we have simplified the process of turning on and off the headlights of a car as an example for you to get the gist of the relay application. Actually, when you give the command to turn on the headlights in your car, this command goes over to the relevant ECU (which stands for Electronic Control Unit) in the car. ECU itself cannot send the voltage directly to different parts of the car such as the headlights, but instead, it gives the command to the relay which is associated with that part. That means it converts the voltage to the voltage level which is required by the headlight to be turned on.
easy to learn
ممتاز 👍
Excellent 👍
Thank you!
Just wondering, if the headlight switch in a car is a 12v connection and the headlights circuit is also 12v - why would you need a relay?
I have a very basic understanding and I thought relays were used to control hvac circuits with lvdc/ac to prevent serious electric shock?
There are a couple of reasons that a relay is used. The main reason is that with higher-powered headlights, it is necessary to use a relay to separate the low-power switching circuit (what turns your lights on and off) and the higher-power circuit to the lights. Most auto headlight relays have two NO contacts so that both headlamps can be powered from one relay. This allows each headlamp circuit to be individually fused and isolated.
Why do we use a relay as an electrical switch when we have transistors?
Transistors are wonderful; devices and very good switches. However, they are limited to low DC voltages (typical;lly 2.5 - 5VDC) and low power (
thx
Superb
Relays de-mystified...very cool.
Thank you, Brett!
Please Make video on Robotics Fanuc and kuka please Make full series.... because future is Robot
Thanks for your topic suggestion! We will happily pass it on to our course developers.
Thanks
You're welcome!
So the photo electric switch uses lets say 24 volts i guessing via a transformer.
can i buy a kit to follow your videos hands on
You can use a PLC simulator software such as PLCSIM to practice what you learn.
subscribe from Egypt 😉👌
can i subscribe with a master prepaid card instead of credit card
I'm not sure but feel free to give it a try on our website.
👍
intersting
Thank you very much !
You are welcome!
thank you very much!
You are very welcome, John! Happy learning.