[RE-wrenches] Looking for remote controlled contactors

Wed Oct 12 08:06:12 PDT 2022

I haven't had problems with contactors failing. I suspect that a lot of
the problems on battery systems happen when contactors are controlled at
battery voltage. 

The nominal voltage of the system is not what the coil will see. A 48
VDC coil might experience 63 VDC. A resistor needs to be put in series
with the coil to prevent over voltage. It's value needs to be calculated
so that it will function, within tolerance, at both the maximum high and
minimum low voltages. 

A 240 V AC contactor coil, on the output of the generator, is quite
reliable. The voltage it sees is within tolerance and the coil is
generally not activated for extended periods (days or weeks or even
years at a time). 

Drake 

Drake Chamberlin 

Athens Electric LLC 

Ohio Electrical Contractor's License 44810 

CO Master Electrician's License 4526 

NABCEP Certified PV Installation Professional

---

On 2022-10-12 07:42, Kirk Herander via RE-wrenches wrote:

> You are correct on this.  
> 
> The failure of any control hardware, IO's / relays / contactor logic along the way from generator sense to PV contactor should result in the coupled grid-tie PV inverter disconnected. Which means the contactor at the PV inverter should be energized "closed" (so PV AC connected normally open) under normal operation (genny off, PV on). 
> 
> Wired as such, It can be done with off the shelf components, and remotely by adding some controlbyweb.com [1] controllers. 
> 
> On Tue, Oct 11, 2022 at 7:49 PM Jason Szumlanski via RE-wrenches <re-wrenches at lists.re-wrenches.org> wrote: 
> I'm not a fan of this strategy because it is not failsafe. Contactors fail. When the coil fails to open the contactor, you will have the PV AC coupled with the generator If he normally closed contactor is used in this manner. 
> 
> I think the question needs to be the converse: How do you turn the PV on remotely only when the generator is not running. 
> 
> Jason Szumlanski 
> Florida Solar Design Group 
> 
> On Tue, Oct 11, 2022, 2:45 PM Maverick Brown via RE-wrenches <re-wrenches at lists.re-wrenches.org> wrote: 
> I'll usually use  a 60 amp contactor with 240Vac coil.  
> 
> The generator powers the coil and opens the Normally Closed contacts disconnecting the grid tie inverter. 
> 
> Maverick Brown
> Off-Grid Solar Commander since 2006
> Maverick Solar Enterprises, Inc. 
> * Solar Commander Remote Power 
> * SunFlow Systems Cathodic Protection 
> maverick at mavericksolar.com
> 512-460-9825 
> 
> On Oct 11, 2022, at 11:26 AM, Kirk Herander via RE-wrenches <re-wrenches at lists.re-wrenches.org> wrote:
> 
> Hi, 
> I'm looking for suggestions on a remote control 60 amp contactor. It can either be true wireless or send a signal down an AC power line to open / close contact at the other end. 
> 
> I'm trying to figure out a non-wired way to turn an AC coupled inverter off when the generator is running, as advised by outback and others. 
> 
> All suggestions welcome thank you. -- 
> 
> Kirk Herander / kirkh at vermont.solar 
> 
> Owner|Principal, VT Solar, LLC 
> 
> _Celebrating our 31st Anniversary 1991-2022!!_ 
> 
> www.vermont.solar [2] 
> 
> dba Vermont Solar Engineering 
> 
> 802.863.1202 _______________________________________________
 _______________________________________________
List sponsored by Redwood Alliance

Pay optional member dues here: http://re-wrenches.org

List Address: RE-wrenches at lists.re-wrenches.org

Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

There are two list archives for searching. When one doesn't work, try
the other:
https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org

List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm

Check out or update participant bios:
http://www.members.re-wrenches.org

  -- 

Kirk Herander / kirkh at vermont.solar 

Owner|Principal, VT Solar, LLC 

_Celebrating our 31st Anniversary 1991-2022!!_ 

www.vermont.solar [2] 

dba Vermont Solar Engineering 

802.863.1202 
_______________________________________________
List sponsored by Redwood Alliance

Pay optional member dues here: http://re-wrenches.org

List Address: RE-wrenches at lists.re-wrenches.org

Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

There are two list archives for searching. When one doesn't work, try
the other:
https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org

List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm

Check out or update participant bios:
http://www.members.re-wrenches.org

Links:
------
[1] http://controlbyweb.com
[2]
https://nam02.safelinks.protection.outlook.com/?url=www.vermontsolarnow.com&data=02%7C01%7C%7C9f0330d75a244870112408d685311841%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636842843233477645&sdata=0NjyuKeQbEK6245SNnk8X4XnP9Q%2B%2BqtvcALkdDghvk4%3D&reserved=0
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20221012/22781fe1/attachment.htm>