[Solved] Ideal Relay Module for 1/2 HP motor.

Hi,

I wanted to create a wireless relay switch for my home motor pump ( which is rated 1/2 {0.5} Horse power ~360 watts )

Which relay module should I select if I wanted to create a RF wireless switch for my motor using arduino nano?

Please do tell me more about the inductive load limits of relay module.

I’m a beginner, so advice would be greatly appreciated.

thanks

How far will it be from the transmitter that tells the receiver to switch the relay?
How many Volts & Amps is the relay switching? 120V, 3A?

CrossRoads:
How far will it be from the transmitter that tells the receiver to switch the relay?
How many Volts & Amps is the relay switching? 120V, 3A?

The transmitter will be about max 10-20 meters ( 1 wall maybe ).
motor voltage is 220-240 volts. so I think relay should be atleast 10A.

I am really concerned about the max 200w inductive load on certain relays.

CrossRoads:
How far will it be from the transmitter that tells the receiver to switch the relay?
How many Volts & Amps is the relay switching? 120V, 3A?

Do you think that a contactor is a much better option than a relay?

You haven't told us what sort of motor.

Noobian:
Hi,

I wanted to create a wireless relay switch for my home motor pump ( which is rated 1/2 {0.5} Horse power ~360 watts )

Which relay module should I select if I wanted to create a RF wireless switch for my motor using arduino nano?

Please do tell me more about the inductive load limits of relay module.

I'm a beginner, so advice would be greatly appreciated.

thanks

Consider using an SSR - Solid State Relay.
Is this an Single Phase, 220V AC, 1/2 HP, Submerged Sump Pump or other?
What is the Starting Amps rating of the motor?

mrsummitville:
Consider using an SSR - Solid State Relay.
Is this an Single Phase, 220V AC, 1/2 HP, Submerged Sump Pump or other?
What is the Starting Amps rating of the motor?

is the SSR same as the sugar cube ones? I saw a few of them with 1/2 hp 220v 10A rating- but they also mentioned resistive load max 1000W and inductive load max 200W.

Yes it is a single phase, 220v ac, 1/2 hp (370W). non submersible pump. I think it is called a monoblock pump in our place.
It is used to pump water from our well (~2 storeys deep) into our overhead tank which is 2 storeys above ground.

I have no Idea about the start amps.Sorry.

Noobian:
is the SSR same as the sugar cube ones? I saw a few of them with 1/2 hp 220v 10A rating- but they also mentioned resistive load max 1000W and inductive load max 200W.

Yes it is a single phase, 220v ac, 1/2 hp (370W). non submersible pump. I think it is called a monoblock pump in our place.
It is used to pump water from our well (~2 storeys deep) into our overhead tank which is 2 storeys above ground.

I have no Idea about the start amps.Sorry.

According to CRYDOM ...

CRYDOM_Tables

See Table #1 ...
A 1/2 HP motor at 240 Volts has 4.2 FLA, Full Load Amps.

See Table #2 ...
A 25 Amp SSR will safely control a motor with 4.2 FLA.
The 20 Amp SSR is a little too small (never under-rate power components)

something like this one ...
EBAY_SSR

$14.00
Output = 25 Amps @ 240 VAC
Input = 3 - 32 Volts DC
Mount to metal, for possible cooling

Or you can use a COIL RELAY with 25 amp 240 AC rated contacts
and deal with the inductive coil kick-back.

Thanks @mrsummitville.

I guess i will settle with a 30A Solid state relay.
Must find a suitable heatsink for it though.

That auction place usually has them as combos.

You didn't say if this was an induction, synchronous or universal motor. The induction
and synchronous types are heavily inductive and require relays capable of handling this,
normally a snubber circuit would be used to reduce arcing. Universal motors are more
forgiving as the armature can act to snub the field winding's kickback.

Noobian:
Thanks @mrsummitville.

I guess i will settle with a 30A Solid state relay.
Must find a suitable heatsink for it though.

Just mount to a smooth clean metal panel or small heat sink.

Something like this ...
D2425_Giant_Heat_Sink

I do not expect the SSR to be On-Off-On-Off-On-Off.
The pump should turn on and stay on for a while
Then turn off and stay off for a while.
This SSR is very "over-rated" because of the inductive motor load.
4 watts of heat, when ON.
Add a ( 10 Amp ? ) Circuit Breaker between AC Power and SSR?
That way the C.B. will trip on Locked Rotor, instead of frying the SSR.

@MarkT

I am really sorry, i do not what type of motor it is, all is know is that it is called a monoblock pump in our place. here is a link to a similar product.
http://www.ebay.in/itm/C-R-I-Monoblock-Water-Pump-0-5-HP-/151465269030?hash=item2344089726:g:cUkAAOSwmUdUWlh8

@mrsummitville.
I happened to have this spare amd cpu heatsink with fan
http://www.chicago-gaming.com/parts/amd_heatsink.jpg
I Think I will use this silver thermal paste which I have and attach the ssr to the heat sink

I intend to use the motor to pump water into my overhead tank which will take about ~30 minutes.
So then load will be ON for 30 minutes, then OFF for 2 or 3 days.

Also The connection to the motor is originating from this 10 amps circuit breaker,
http://www.havells.com/Product.aspx?s=204
but it is before the ssr? will that be a problem since it is not between the ssr and the motor?

Noobian:
I am really sorry, i do not what type of motor it is, all is know is that it is called a monoblock pump in our place. here is a link to a similar product.

Not your problem, but that is a very poor listing - suggesting the pump can pump liquid at "300C" and operate at "400C" which is most improbable, citing multiple different flow ratings and omitting the essential specification of the "head" that it can pump. :astonished:

Note that when posting links to eBay, remove the question mark and all following.

Noobian:
but it is before the SSR?

Which is precisely where it must always be in order to protect the equipment.

Sounds like a single phase induction motor. The temperature specs are probably in kelvin, not centigrade,
making it 57C and 127C for max fluid and max ambient temps.

MarkT:
Sounds like a single phase induction motor.

Of course.

MarkT:
The temperature specs are probably in Kelvin, not centigrade,

Well, that would be common practice, wouldn't it?

Still makes no sense. :roll_eyes:

@Paul__B
The ebay link was for a similar product, anyway thanks for the tip on link, i'll keep that in mind when I post an ebay link next time.
Here is the link to the Manufacturer of my motor, although they dont have the exact model since mine is 20 years old now, they probaby replaced it with a newer model.

@MarkT
So if it is an induction motor, a 240v 30A SSR will be enough?