convert my electric manual start generator to an auto start

What we did a long time ago (1965 -before PIC's) was to connect a light in series with a battery , the generator control board and the float switch. (the pump motor could not activate the starting relay )

When the water level rose the switch went on and the circuit was completed activating a relay which then initiated the starting procedure on the gen set. The pump was eventually started when the power was good. To achieve this we used solenoid activated clockwork timers.

This system work flawlessly and was real cheap.

I think by now any gen-set manufacturer will have automatic starting ability but the trick is to use a light bulb to supply the activating load.

If I had to do it again today I may go for a PIC to do all the timing delays and even report on any possible fault.

Your battery also need special consideration. It may be wise to have the gen-set activated at least once a month and have the battery charged.

Hi I like simple and it sounds like you have a proven system that has worked for years. I know that I have to install a auto transfer switch to make sure that I don't back feed a main power line and a level switch to start every thing going and your part sounds simple and like a fun project too, but a picture is worth a thousand words to me could you draw up a rough schemetic of the system for me. Thanks

Because we work at home and power outages are costly to us, we installed a 5KW generator.

The dealer installed it with a transfer switch that automatically starts the gen when Edison decides to take a break.

Edison power energizes a solenoid that keeps the switch in that position, when the power goes off a spring moves it to the gen position. I would think any gen dealer could furnish the parts, you just need to use a float to actuate it.

You could use a float switch (or solid state detector) that is fitted in small vessels bilge systems that connects to an electric submersable pump. although you do not need the pump, the control gear would be useful. Not very expensive either.

It WILL be much cheaper and much simpler to buy and install a conventional battery back-up sump pump. They 'float' on line when power is there, and the battery will run the pump for a few hours as needed when/if the power goes off. Works well IF the pumping need is of relatively short duration (not continually.) Unless you have a very large fuel supply, generator run time may not be long enough to bridge the power outage anyway.

Hi Rambler3-too

Just to clarify.

You don't seem to have (reliable) electricity there.

You want the float switch to start the gen-set to power the dewatering pump.

Contact the suppliers of Onan and buy a automatic start on demand facility.

Make sure to ask them if a float switch and motor will activate it.

If not you will also have to couple a light bulb in the system to fool the generator to start.

I don't understand the need for the light bulb.

Long ago I was supplying automatic gen sets to off grid farmers.

The principle it worked on was that the first light is switched on the 12volt current flowing through the bulb was enough to pull up a relay to initiate the starting sequence. (and switch the battery out).

Business was good and I was the light in many lives.

One day a cherry farmer ask to automatize his cooler room. The same system was used and it went well. On the fourth day he contacted me and complained that it did not work the previous night.

After investigation it was found that he did not get out of bed that night to police the system and also did not switch on any light.

Apparently the resistance in the motor prohibited the flow of enough 12 v current to activate the relay. the problem was solved by letting the temperature switch switching a light bulb to start.

This was in 1965 and maybe there are improved systems in the market.

I am not electrical and would like someone to tell me if switching on the float switch on a dewatering pump will start a start on demand automatic gen-set.

Hi Rambler ; are you on city water pressure or do you pump your own ?

If you are hooked up to the city water main and are recieving water pressure from the main , you might concider installing a really nifty device that is sold here in Ontario Canada as the " sump buddy ". Its an inexpensive little unit that uses the water pressure supplied by your connection to the city water system . It does not use electricity but syphons the water out by using the city supplied water pressure.

Its a very simple device and therefore i assume it to be very reliable . You could use it as your primary stand alone or as a back up to the generator system for piece of mind. If you are only worried about possible power outages while you are gone , this thing should work well for you.

Note : this unit works with city water pressure only , if you pump your own water from a well etc. it will not work .

Hope this helps.

i think i can help you with this if you still need assistance. i work as a controls Technion at a company that builds machinery. my ideas are sometimes a bit unorthodox but with a little ambition i can usually get things to work. i have built a lot of crazy inventions including remote starting for my generator on my service truck. let me know if your willing to go through with this.