Hello, I'm trying to find a safe way to make a remote cutoff switch upto 100 amps if it's possible? Does anyone know of a device that can interface with a micro controller to do something like this?
Edit: I was looking at maybe A relay of some kind. I wasn't sure and I wanted to get the community Advice.
Joseph
Hello
Search for a "contactor"
The one I found was This https://www.aliexpress.com/item/3256801362215482.html. But I wasn't sure. That why I ask in here. I'm looking at contactors now. Can you tell me which one I'm looking for please? There are so many out there.
Edit: What I mean is there it not one I can find that with a 3v to 5v trigger.
Joseph
Do it in two steps. Use a line voltage contactor with a sense switch to confirm operation. Use a 5v to line voltage SSR to drive the contactor.
Hello madmark2150, Which voltage contactor would be good for something like this? I'm searching and there are hundards or even thousands of different ones out there. And I have no clue which one would be the best for something like this. The SSD solid state relay normally I use something like this https://www.alibaba.com/pla/SSR-40DA-DC-to-AC-SSR_60825845854.html?mark=google_shopping&biz=pla&pcy=US&searchText=Solid+State+Relay&product_id=60825845854&src=sem_ggl&from=sem_ggl&cmpgn=15581229768&adgrp=132611869873&fditm=&tgt=pla-1082573610178&locintrst=&locphyscl=9003955&mtchtyp=&ntwrk=u&device=c&dvcmdl=&creative=569900552593&plcmnt=&plcmntcat=&p1=&p2=&aceid=&position=&localKeyword=&pla_prdid=60825845854&pla_country=US&pla_lang=en&gclid=Cj0KCQjwuO6WBhDLARIsAIdeyDKEfJilzO-v7gS4K0XxIGkUEMC83nJudTRYHAAsiNqkUFllZ0TDj7EaApgCEALw_wcB I haven't had any problems with them. Would that one work?
Joseph
Hi, @josephchrzempiec
AC or DC current and what voltage level are you switching?
Tom... 
Hey Tom, I'm sorry I forgot to say that, Thank you. It's miains AC 120v and Current is 50 amps it's for solar setup that is not connected into the house. It's basically has it's own standalone setup in the house but not connected to the panel box.
Joseph
I’m not sure if buy one from Aliexpress , you need a quality device - look in RS components , etc .
Don’t rely on the operation of a remote switch to give you power isolation . Any any devices need to be labelled with “ remotely switched may start unexpectedly” .
The operating coil of a contactor may still take enough current to make long distance operation difficult
What’s the project - need to know as you might be attempting something g a bit iffy , and we do t want to offer advice on such systems
This is for me when I'm away from home. I run a couple of small servers some back up lights for the house and plan to expand soon. There is nothing bit iffy as you put it. I already state it's for my solar system I'm running. When I'm not home anything happens I can shut it off remotely. Not sure How Bit iffy plays into that when It's my home.
Joseph
The ssr you selected is ok. even a cheap one should workmsince its just energizing the contactor (a small current).
The contactor needs to have a coil voltage compatible with your line voltage and a contact rating 25% LARGER than your anticipated load. You can get an optional switch on the contactor that can be fed back to your Arduino to confirm that the contactor actually pulled in. This way you can sense a fail in either the SSR or contactor. A simple NE2 neon bulb with a 47k resistor attached at the contactor coil will let you know visually which device failed. Some contactors come with a test button where you can manually activate the contactor.
New search: 100a Automatic transfer switch
this is the exact thing you need.
Hey madmark2150, Do you have any recommendations on which contactor would be good? To be honest I have no clue. I have search tons of them and I don't even know which one I'm in need of. A 100a version seems to be maybe the best. But again I have no clue which one.
Edit: transfer switches useally are from mains power grid to off grid power for solar systems correct? Mine is not hooked to mains Power grid.
Joseph
Ohh I see instead of transfering it to mains power not connect that part and there isa connector for a remote switch to trigger the Automatic transfer switch Like this one https://www.amazon.com/GAEYAELE-W2R-3P-Mounted-Automatic-Transfer/dp/B07J5JXFGH and have it just cut off the power.
Edit: Would that work? It looks like it's got a remote switch and I think it might work. I can connect it a micro controller with a opto isolator and a small relay.
Joseph
Now you're cookin' ! And you can parallel the contacts so a 3phase 30A contactor can switch 90a single phase with the three phase contacts all paralled.
Thank you so much. Looking into it now.
Joseph
Just small point if you switching the panels upstream of the inverter , you will need to de rate your contactor as you will be switching DC.
Massively de-rate it.
For DC, you can only use a contactor specifically designed for DC.
Note for example that relays commonly rated for 230 VAC are only rated for 28 VDC.
Hi,
Can you please draw us a basic block diagram of your system and what you are trying to do?
Thanks.. Tom...
HAHA... me drawing. I got better luck asking a 5 year old to draw for me. But I can try.
Joseph
Hi,
Thanks for the diagram.
What is the power rating of the Inverter?
What is the battery voltage?
Tom..
