Generator Controller

Status
Not open for further replies.
You will probably have to go with a commercial version of Kohler, or Cummins/Onan. Any brand that has a two wire start capability. I don’t think Generac has any until you get to the bigger sizes. RV generators are mostly two wire start, but most are only 120 volt output, until you get the bigger generators. You will also need a two wire start compatible transferswitch, where Generac’s is not without a lot of modifications. I have a 20KW Cummins/Onan, and it appears to have remote start capability. It’s not much more in price than the Generac.
 

Attachments

  • IMG_1554.jpeg
    IMG_1554.jpeg
    103.8 KB · Views: 10
hillbilly1 said:
Not too difficult if you’re fluent in controls. You would need a relay powered from each pressure switch to give you the necessary contact inputs for the timer, the pumps are probably driven directly off the pressure switches, so contactors will be needed for each pump to delay the start sequence. Closure of any pressure switch (booster and main pump) would reset the timer, the timer would drive the generator start. (Another timer would delay the pump contactors, only one would be needed just to energize the contactors once the generator is up to speed)
Click to expand...
And may need a battery to run the control system and of course arranged so charging goes on during normal power or anytime generator is running. Small PLC might be the best controller - many those can run on 24VDC some maybe even 12 VDC.
 
GAK said:
Programming it to only run for certain predetermined times would be a better way to go.
Click to expand...

That wont really work.

So you set it up to start every 6 six hours to pressurize the system. Then right after it start 3 showers are taken.

Now you have no water pressure for 5 hours.
 
I had a customer who wanted a battery system for a well.

After doing a design overview with him, we ended up going with a generator. The battery was cost prohibitive and infeasible.

So I’m not promoting battery systems. 99% of the time they are far more expensive and deliver for less for the money that’s generator.

But I still think in your situation an ESS might be a viable solution. And I think it can acquires for far less than $20k.

You could even build your own with batteries and an inverter. You don’t have to use Tesla or Generac systems.
 
Tesla or Generac battery systems don't play with generators. Outback and Sol-Ark do. There is a lot of learning curve. It is not plug and play.

Fuel burning generators are by far the cheaper way to go. Unless the power stays out for weeks out of the year, and it's sunny.

It is reasonable to want to 2 wire start and stop in response to a call. Controls will be somewhat complex. You would have to pay me to start design on a system like that. It would be time consuming to design, order parts, construct controls, and build.
 
GAK said:
The pumps are run through contractors with a 240 volt coil. One side of the coil runs through the pressure switch, the other side is run through a float in the cistern to keep the pump from running dry.
Click to expand...
Most standard well pump pressure switches are double pole, are both poles being used? The float switch should be common to all of the booster pump contactors, so that should free up one of the pressure switch contacts. That contact can be used in series with a 12vdc on delay relay that is in series with the start contact from the transferswitch. The generator will only start if power is lost, and any pressure switch is closed. Use a 20 KW generator so all pumps can run if needed, so additional load shedding would not be necessary. If you use a time clock, it will need a separate power source to keep time if mechanical, or power to transfer the contacts when utility and generator is off. Took about 15 minutes to design that. Can draw it out when I have more time.
 
hillbilly1 said:
Most standard well pump pressure switches are double pole, are both poles being used? The float switch should be common to all of the booster pump contactors, so that should free up one of the pressure switch contacts. That contact can be used in series with a 12vdc on delay relay that is in series with the start contact from the transferswitch. The generator will only start if power is lost, and any pressure switch is closed. Use a 20 KW generator so all pumps can run if needed, so additional load shedding would not be necessary. If you use a time clock, it will need a separate power source to keep time if mechanical, or power to transfer the contacts when utility and generator is off. Took about 15 minutes to design that. Can draw it out when I have more time.
Click to expand...
Yes one side of the pressure switch is free to use for that.
 
You need to add in some delay on loading after engine start. Don't want to be bringing it on line with the loads already trying to run. And other stuff like that. There are always more layers to this sort of thing. It is never as easy as "just" do this or that. Controls are like that.
 
Birken Vogt said:
You need to add in some delay on loading after engine start. Don't want to be bringing it on line with the loads already trying to run. And other stuff like that. There are always more layers to this sort of thing. It is never as easy as "just" do this or that. Controls are like that.
Click to expand...
Op said the pumps are on contactors, not a big deal to add a timer. Not that complicated of a control scheme.
 
Certainly not that complicated but there may be one thing that presents a challenge. So you add some delays, they have to be sourced, mounted, installed and tested under various conditions, and thought about what sort of failure modes could occur that you did not think about initially. I speak from experience. Charge the client accordingly and do not belittle your own experience.
 
Finally got a chance to draw it out, the pressure switch contacts need to be parallel instead of series, and with an off delay instead of on delay relay. If the off delay relay fails, generator will run as normal, it just will not shut down once the load is satisfied.
 
It's a day tank to pressurizing individual system including indiviual water tanks, as I've read.
I'm missing something if one loses power one has water but nothing heated?

My belief is you need to also consider some of the water recovery rates on the individual water heaters.
The 70% rate run applies to water heaters.

A lot of numbers were presented throughout addressing the electrical side and not much on a total accounting
of the water system in toto or even revising anything about the existing system application.

A nice line diagram with all the numbers accounting for both water and power aspects for would be ideal!
 
hillbilly1 said:
Finally got a chance to draw it out, the pressure switch contacts need to be parallel instead of series, and with an off delay instead of on delay relay. If the off delay relay fails, generator will run as normal, it just will not shut down once the load is satisfied.
Click to expand...
Will the off delay timer be reset each time the pressure switch closes? As in if the generator is already running and there is another call from the pressure switch.

And would you power the timer from the 12V battery in the generator?
 
GAK said:
Will the off delay timer be reset each time the pressure switch closes? As in if the generator is already running and there is another call from the pressure switch.

And would you power the timer from the 12V battery in the generator?
Click to expand...
Yes, once all loads are satisfied, the timer starts, but resets if any of the pressure switches close again, and yes, use power from the generator battery.
 
The Cummins/Onan has programmable load shed relays that can be used to lockout however many pumps you want when the generator is running, and one output could be used to drive a time delay relay to delay the loads when the generator first starts.
 
Status
Not open for further replies.
Top