2 coil contactor?

[monkey5]

So is there such a thing as a 2 coil contactor,
Current set up is my immersion is controlled by my nest but via a contactor. But due to having solar fitted What I'm wanting to do is control the immersion by the solic 200 (feeds the immersion when excess power going to grid) and still the nest, so the only way I can think of is via a 2 coil contactor so either device can control the immersion but not be connected together in any way. I'm probably over thinking and missing a really simple thing but any ideas would be grateful. I've asked the wholesalers for such a thing and nothing came to light.
Cheers in advance

 

[Barx]

Never seen one with 2 coils. an option would be an 'double throw' one. In fact, probably need to be a relay. Only ever seen contactors as Normally open or Normally closed.
In you get a double throw. You could put your 'default' supply on the N/C contact and the other on the N/O. The the Common would be your output to the immersion.
How you planning on switching between the 2 thoough?

 

[Geoff1946]

You need a relay with a changeover contact. Coil driven from Solic. NO contact from Solic. NC contact from Nest. Output drives contactor.

 

[Barx]

Thinking more about it.What about putting the Solic through the Normally Closed connection.
Then Nest to Normally open with a link to to power the relay. So Nest switches on (assuming you're using it to boost}, activates the relay / contactor, isolating the Solic and allowing the Nest power through.
When Nest turns off, relay turns off and back to whatever the Solic provides as and when.

 

[Andy™]

Never seen one with 2 coils. an option would be an 'double throw' one. In fact, probably need to be a relay. Only ever seen contactors as Normally open or Normally closed.
In you get a double throw. You could put your 'default' supply on the N/C contact and the other on the N/O. The the Common would be your output to the immersion.
How you planning on switching between the 2 thoough?

2NO2NC contactor can be used as changeover

 

[binky]

You need a relay with a changeover contact. Coil driven from Solic. NO contact from Solic. NC contact from Nest. Output drives contactor.

I don't think that will work as the solic isn't a simple on off device.

What I would do is wire it in parallel using two junction boxes. That way each device will work independently of each other.

 

[Barx]

You need a relay with a changeover contact. Coil driven from Solic. NO contact from Solic. NC contact from Nest. Output drives contactor.

Why a relay AND contactor? could do it with a DPDT relay with 230Vac coil. Unless I've miss understood the requirements, which happens alot according to the wife.

 

[Geoff1946]

Why a relay AND contactor? could do it with a DPDT relay with 230Vac coil. Unless I've miss understood the requirements, which happens alot according to the wife.

Dead right, but I was thinking small (cheap) compact relay, contactor for the power. Can be done in one suitably rated device. BUT note Binky's comments. I know nothing about Solic equipment and was assuming a simple power ON or OFF situation. I think some of the other responses make the same assumption.

 

[Barx]

Dead right, but I was thinking small (cheap) compact relay, contactor for the power. Can be done in one suitably rated device. BUT note Binky's comments. I know nothing about Solic equipment and was assuming a simple power ON or OFF situation. I think some of the other responses make the same assumption.

Yes, device like the Solic typically use PWM to regulate power output, hence I would put that on the N/C contact adn trigger the relay coil with the Nest which is a standard 230Vac output.
Also, changes are the OP wants to use solar generation where possible as default and Boost with Nest. So as the Nest kicks in to boost, it will cut off the Solic.

One thing I would at for @monkey5 make sure whatever you get is at least 2 pole so you can change over the Neutral too. Single Pole will only allow switch of Live.

 

[binky]

Dead right, but I was thinking small (cheap) compact relay, contactor for the power. Can be done in one suitably rated device. BUT note Binky's comments. I know nothing about Solic equipment and was assuming a simple power ON or OFF situation. I think some of the other responses make the same assumption.

immersion controllers tend to release energy in pulses, that way they can power a 2kw load with only say, 250W of spare solar energy. It's also why they can't be used with electronic contolled heating loads, as the pulsing trashes the electronics.

I have wired a parrallel bypass before. Immersion permanent supply to a 32A JB, take a line off for the solic, with the output connected to another 32A JB that then goes to the immersion. From first JB, connect a second line to the relay controlled by the nest, and again output to 2nd JB. Simple and works.

 

[Phoenix]

I have wired a parrallel bypass before. Immersion permanent supply to a 32A JB, take a line off for the solic, with the output connected to another 32A JB that then goes to the immersion. From first JB, connect a second line to the relay controlled by the nest, and again output to 2nd JB. Simple and works.

The only thing I'd be concerned about, is would the solac have problems with volts appearing on the output, probably best not to do unless the manufacturer states that its ok to do that

 

[binky]

The only thing I'd be concerned about, is would the solac have problems with volts appearing on the output, probably best not to do unless the manufacturer states that its ok to do that

Doesn't do it any harm, it outputs 240v, and the ones I've installed like this have been working for over 5 years. Plus if the nest is powering up the immersion, you aren't likely to have spare energy to get the solic working.