Motor control

[pratikkhandelwal]

Is there any way to control 3 hp and 5 hp motor using relay boards? If so what are the relay board available? Because rated current of 3hp and 5hp motor will be above 10amp and traditional relay boards available are 10 amps.

[dan]

Usually you would connect one of the SIP relays to control a larger relay that would control the motor. You would need to find out what kind of relays are available in your area.

[pratikkhandelwal]

DAN

There are solid state relays available in my country but can you provide me how we can interface them with our traditional relays(10amps)? Also can you provide wiring diagrams to interface 10amps relays with solid state relays. 
link contains relay available in my country.
https://www.amazon.in/24V-380V-SSR-100-S...ate+relays

[dan]

I have not worked with solid state relays.

You best bet for information is google.

Dan

[draggaj]

DAN

There are solid state relays available in my country but can you provide me how we can interface them with our traditional relays(10amps)? Also can you provide wiring diagrams to interface 10amps relays with solid state relays. 
link contains relay available in my country.
https://www.amazon.in/24V-380V-SSR-100-S...ate+relays

given that SSR will take a 3vDC signal to operate it, then the example sketch attached should be sufficient info for connection.
Just remember you're dealing with 240VAC on one side of this (usual cautions apply -e.g. it will kill you and you are dealing with water and electricity). Best to get a qualified electrician to set it up for you.

Other thing to note is most SSRs of that form factor have a metal plate on the bottom. This is meant as a secure mounting (use it so - you don't want 240VAC flapping around on the end of some terminals floating in mid air) That plate is also meant for bolting to a heatsink. If the load is heavy current, then the SSR will get warm or hot.....mount it on a heatsink if you are in doubt about the SSR's heat load.
Read the spec sheet on the SSR. It 'should' tell you when you need to add an external heatsink.
Lastly, the heatsink and or SSR mounting plate should be normally earthed to the AC mains earth....

Repeat - if you are not competent or qualified to work on AC mains - pay for an electrician....its cheaper than a fine or a funeral.
Bob

[RWoerz]

I know this is an old thread but you can just use the 24 volt output of one of your sprinkler relays to run a larger relay. I takes about 13amps at 240vac to run a 5HP motor so a relay rated at 20 amps should do the trick. Like this one.

https://www.amazon.com/Bosch-0332019203-...921&sr=8-8

[DrLabel]

Is better to use a relay to control a Contactor:
https://en.wikipedia.org/wiki/Contactor#...r%20switch.
If you use a relay is going to be destroy very fast, to control a motor us always a contactor.
"Unlike general-purpose relays, contactors are designed to be directly connected to high-current load devices. "