Differences Between Relays and Contactors

preview_player
Показать описание
In today’s video we are going to be looking at the differences between several pieces of hardware that often get confused even though they are intended for very different purposes. This hardware includes: power supplies, inverters, transformers and voltage converters. All of this hardware is intended to alter or change the type of power or voltage you might be using. The result you need will directly impact which type of hardware you may choose to use. However, it is very common for people to confuse the different types of hardware. Let’s discuss each type and what it is intended to do… so hopefully by the end of this video you will have a very clear understanding of each... and when you might want to use them.

Let’s first start with power supplies. A power supply can have many different functions, but most of the time, the power supply use intended to take one type of power and convert it to another type of power. The most common example of this is a power supply that takes AC voltage and converts it to DC voltage. While it is very common to use power supplies in industrial applications, one very common place you will see a power supply used is for the gadgets you have around your home such as: your smartphone, laptop or tablet and many other devices we use on a daily basis. You may have noticed that most devices you have come with a power cord with a bulky block on the end of it. This block is where you will typically find the power supply. So most of your devices do not use AC power, which is the type of power being supplied to your home. These devices more commonly use some form or DC power.

Now let’s talk about inverters, an inverter works in a similar manner to the power supply with one major difference, instead of converting AC power to DC power… the inverter does the opposite. tI will change DC power to AC power. DC power is created by devices such as solar panels or batteries, but often we need AC power for the things we commonly use. For example, if you have solar panels on your roof, the power that is being created comes in the for of direct current (..or DC). But, in our homes most of the things that we need to power require alternating current (..or AC). So in order to convert the DC power that is generated by the solar panels... an inverter is used.

Lastly, let’s talk about transformers. For more detailed information about how transformers work, please see our other video which we will link in the description below. Similar to a power converter that is used for changing only DC power… the transformer is intended to be used with AC power. More specifically, transformer converts one type of AC power to a different type of AC power. For example, your home commonly uses 120 volt AC. However, there are some electrical devices we use in and around our homes that need AC power, but cannot operate with 120VAC. So in this case a transformer is used. If you have an automatic sprinkling system, chances are the valves in that sprinkling system require 24 volts AC. To do this, a transformer converts 120VAC that is available in our home, to 24VAC so the sprinkler valves can operate properly. Transformers come in many different shapes and sizes. It is important to note, that transformers can both convert AC power up and down. So if a greater AC voltage is needed, a transformer will be used… and the same can be said when a lower AC voltage is needed.

So let’s quickly recap…. Power supplies most commonly convert AC power to DC power. Power converters are used to change the voltage within the DC range only. ...and UPS’s are intended to continue to supply power in the event of a power failure and are often used with a regular power supply. Inverters are intended to change DC power, back to AC power. …and lastly, transformer are used to change one type of AC voltage, to another type of AC voltage.. Up or down.

Additional Links -

Website:
Engineering Page:
Panel Fabrication Page:
Procurement Services Page:
Manufacturers Page:
Relays & Timers:
PLCs & IO:
Panel Hardware:
Enclosures:
Tools & Supplies:
Рекомендации по теме
Комментарии
Автор

very clear and professional video. thanks for this information.

pointblank
Автор

Missed a very important thing about the differences when saying that "Relays can be either NC or NO depending on the type, where contactors give you 3 sets of NO contacts". But you jumped one of the most important bullet points; Auxilary Contacts. This means that Auxilary blocks can be mounted onto the contactor, some models on the front whilst other on the side, this will give you multiple functions as in NC & NO contacts.

Legolize
Автор

some addition.

Most relays have single break contact. Most contactors have main and auxilliary contact as Double Break contact. Double break contacts reduce arcing at contact while making or breaking. Speed of closing of Contactor contact is very high as compared to relays, there by reducing arcing time while making or breaking. So contactors can carry higher current. Contactors have Main contacts as Normally Open mostly and auxilliary contacts as NC or NO or Borth. While relays mostly have Change over contacts. Power contactors ( contactors with high current ratings ) contacts can be replacable or servicable. Power contactors may have arc chutes to extinguish the arc.

ToolsAandLogic
Автор

Hi thanks for the great video. I was just wondering. Can you put just two hot wires from a two pole fuse holder to a three pole overload relay (ex. L1✓ L2✓ L3×)??

Thanks again

Jay-trpx
Автор

We have relays using for substation to control or isolate high voltage equipment... please note this can be happens with CT and PT

sharafsiyad
Автор

Thanks for a nice concise video! Question: What temperature extremes can contactors withstand for very harsh environments? For example -70C to +85C? How about environments with high levels of shock and vibration, as in a HUMVEE? Thanks, Peter

pholzer
Автор

How is fly back from the coil handled ?

insylem
Автор

nothing mentioned about activation voltages AC vs DC etc

edwardgilmour
Автор

Can we use 24Vac contactor coil with 12V dc supply??

Alyaqeen-fz
Автор

What about a solenoid?? What's the difference with that?

notnecessary
Автор

The thunder gods themselves wet their pants every time a contactor switches 12500 amps

alexrossouw
Автор

How to calculate the resistor and capacitor valve(Snubber Circuit) that we connect across coil of contactors (A1 and A2)

mohdkhalid
Автор

Can we use t shape 30A relay for controlling 1hp water pump or should I use contractors

ashokakp
Автор

In control panel, which one gives on and off status
Pls reply

chethuharireddy
Автор

Can i use a relay(5 amps) to power my 0.33 hp motor /1 phase ?sir plz let me know

sachinkanchan
Автор

Another difference is auto correct constantly tries to correct contractor... see what I mean.

wheelie
Автор

Should be explained with animation. Easy to understand.

syedfaheem
Автор

Hello sir, i am also from electrical backgroud, i want to explore my knowledge in control panel and PLC programming, i wanted to work with your company ..

iacademy
Автор

Plz define and explain contactor for me on comments

muhammadiftikharhassan
Автор

Really. New world do not use rellay s any more.
And no no no. Please.
Wtf

fannienel