Voltage drop out circuit

[WGB]

Hi all.
Been here for some time, just my second post, first thread.  This is a great forum, I’ve learned a lot, still bought a ST head though LOL. Just for some back round. My long term plans are to be off grid, it will cost over 10 grand to get power to me, good seed fund for alternative energy system. I’m cutting back on usage, building a wind generator now, PV, generator just got yesterday, hybrid, etc. system. Also going to buy Utterpowers CD.
I just picked up a new 12KW ST that I’m going to make a PTO set up for now, 120/240 volt back up power and to run heavy loads.  It’s going on a 32 hp Kubota tractor, with digital RPM read out, dead nuts RPM control (if not over loaded).
  I have searched and not run onto any circuit yet that will do what I want. I’d like to build a circuit that will control a contactor, pull in the contactor at say 108-110 volt, drop out at 125-127 volt, you guys see where I’m going!
Any circuits out there? Any ideas?
Thanks
Bill

[Tom]

If you plan to PV and wind you will need inverters. Get them first and they will provide voltage control and switching you are after. They include frequency limits too. With that big of a generator you will be able to charge batteries and power your construction project no problem.

[WGB]

If you plan to PV and wind you will need inverters. Get them first and they will provide voltage control and switching you are after. They include frequency limits too. With that big of a generator you will be able to charge batteries and power your construction project no problem.

Sorry I wasn't very clear, I want this for the ST generator output.
As far as inverters, it will be awhile, I've been leaning to Xantrex.
Thanks for the reply.

[Tom]

Yup, the inverters will do that for the ST output and switch to batteries automatically. We're off-grid here and when it is time to start the genny I just fire it up and when the voltage and frequency is within range for 2 min the inverters switch the house load to generator power and start charging batteries any extra power. On shutdown I just cut the fuel and as the generator spins down the inverters kick in and switch to battery power. The computers and other electronics in the house never notice the difference.

By doing the inverters and a small battery bank now you can have power on site 24/7 and only fire up the tractor when necessary to charge batteries. You can also keep the tractor loaded to run efficiently. If you are just running power tools during construction then perhaps you don't really need a contacter.

[cschuerm]

Bill,
Timemark makes a little module that does exactly what you're asking for.  It's a model 268 over/under voltage monitor.  Dry contact output to energize a contactor only when the voltage is between the upper and lower setpoints.
www.time-mark.com


cheers,
Chris

[WGB]

Bill,
Timemark makes a little module that does exactly what you're asking for.  It's a model 268 over/under voltage monitor.  Dry contact output to energize a contactor only when the voltage is between the upper and lower setpoints.
www.time-mark.com
cheers,
Chris

Thanks Chris, have you used one?
Looks like what what I want.

[WGB]

Time Mark has many things I've been looking for, good info.
Chris http://www.time-mark.com/products.php?id=143 looks like a good relay for my application too.

[cschuerm]

Bill,
I've used many of Timemark's products.  Good company and they stand behind their hardware.  I use a LOT of phase monitors for industrial applications and they've replaced units blown up (I mean physically exploded) by lightning under warranty.
They also have a low/hi frequency monitor module (292) which would be a nifty overspeed shutdown monitor for a Lister rig.

cheers,
Chris

[Oiler]

Tom


What make and size of inverter do you use?


Cheers

[sailawayrb]

 I have searched and not run onto any circuit yet that will do what I want. I’d like to build a circuit that will control a contactor, pull in the contactor at say 108-110 volt, drop out at 125-127 volt, you guys see where I’m going!
Any circuits out there? Any ideas?

I use a Magnercraft 831VS-120A for voltage sensor relay.  You can set the upper and lower voltage threshold, as well as adjustable time delay.  It can purchased here for about $44:

http://www.bb-elec.com/product_family.asp?FamilyId=225

I use a Magnercraft W6240ASX-1 solid state relay (in lieu of mechanical contactor) to do 120VAC drop in and pull out.  Mine is rated at 40A and adequate for my 120VAC/3.5KW setup.  It can be purchased here for about $25:

http://www.bb-elec.com/product_family.asp?FamilyId=224

Main purpose for this is to preclude a house "brown out" by disconnecting the generator from transfer switch in the event of an emergency engine shutdown event (triggered by high vibration, high engine temp, low oil level, or if smoke/CO is detected).  Another side benefit is that since generator voltage is proportional to engine speed, the voltage sensor relay may be used to provide engine overspeed protection as well.  For my setup, high engine speed will cause high voltage, which will cause the 120VAC to be pulled out, which will cause my 12VDC switching power supply to be pulled out, which will initiate an emergency engine shutdown event (which for my setup causes a pneumatic control spool valve to be de-energized, which in turn causes CO2 to be dumped into the engine intake).  I elected to go the CO2 route because I already plumbed the engine intake for propane.  I use propane for fumigation (I burn SVO) and for additional power (4.5KW) when needed.

[Tom]

Tom

What make and size of inverter do you use?

Cheers

I have 2 of the Outback vfx3648 inverters.

[WGB]

 I have searched and not run onto any circuit yet that will do what I want. I’d like to build a circuit that will control a contactor, pull in the contactor at say 108-110 volt, drop out at 125-127 volt, you guys see where I’m going!
Any circuits out there? Any ideas?

I use a Magnercraft 831VS-120A for voltage sensor relay.  You can set the upper and lower voltage threshold, as well as adjustable time delay.  It can purchased here for about $44:

http://www.bb-elec.com/product_family.asp?FamilyId=225

I use a Magnercraft W6240ASX-1 solid state relay (in lieu of mechanical contactor) to do 120VAC drop in and pull out.  Mine is rated at 40A and adequate for my 120VAC/3.5KW setup.  It can be purchased here for about $25:

http://www.bb-elec.com/product_family.asp?FamilyId=224

Main purpose for this is to preclude a house "brown out" by disconnecting the generator from transfer switch in the event of an emergency engine shutdown event (triggered by high vibration, high engine temp, low oil level, or if smoke/CO is detected).  Another side benefit is that since generator voltage is proportional to engine speed, the voltage sensor relay may be used to provide engine overspeed protection as well.  For my setup, high engine speed will cause high voltage, which will cause the 120VAC to be pulled out, which will cause my 12VDC switching power supply to be pulled out, which will initiate an emergency engine shutdown event (which for my setup causes a pneumatic control spool valve to be de-energized, which in turn causes CO2 to be dumped into the engine intake).  I elected to go the CO2 route because I already plumbed the engine intake for propane.  I use propane for fumigation (I burn SVO) and for additional power (4.5KW) when needed.

Yep, some of what I want the circuit to do also.

Thanks everyone for the input.