On loss of utility power, Koehler residential generator (new) automatically starts up but then shuts down within seconds with ac sens loss fault; only behaves like that on loss of utility power.

Turns out it was the Manual-off-Auto switch that was bad. My DVM showed a voltage drop across the switch. The controller wasn't getting enough power.

One good thing about it was it forced me to really study the schematics to understand how everything worked. I'm now in the process of designing my own esp32 based controller, with wifi connectivity, to replace the stock control board.

• The completely automatic transfer switch monitors incoming voltage from the utility line, around the clock.
• When utility power is interrupted, the automatic transfer switch immediately senses the problem and signals the generator to start.
• Once the generator is running at proper speed, the automatic transfer switch safely shuts off the utility line and simultaneously opens the generator power line from the generator.
• Within seconds, your generator system begins supplying electricity to the critical emergency circuits of your home or business. The transfer switch continues to monitor the utility line conditions.
• When the automatic transfer switch senses the utility line voltage has returned at a steady state, it re-transfers the electrical load back to the utility line and resumes monitoring for subsequent utility loss. The generator will continue to run for an engine cool-down period of several minutes while the entire system stands ready for the next power outage.

https://www.dieselgeneratortech.com/generator-sets/Information-of-Starting-Battery-in-Diesel-Generator-Set.html

transfer switch is bad and could electrocute line workers if your power goes out

The transfer switch could be bad, worn internally, a manual switch, or a semi-automatic transfer switch. Check the transfer switch part numbers and google them to find out exactly what kind they are. In some places fully automatic transfer switches are not permitted in a residential environment.

Check fuel pressure, oil pressure switch, AC output from stator, check rotor and diodes

Is there a fault?? All UL listed generators including Kohler are required to lockout on a fault on shut down. This really sounds like a problem with your 2-wire auto start connection between your automatic transfer switch and genset. RDT model automatic transfer switch it is the 2 middle wires on the green connector and terminals 3&4 in the generator. close to run and open to shut down. Any open at any time will cause the unit to shut down. The 12 will shut down instantly upon an open because your 5 minute cool down is built into the transfer switch.

Most CRT displays sold for use in the US & Canada (and probably everywhere else for that matter) require AC. This is because AC is the most popular mode as it is easily stepped up for long distance transmission and down for use in commercial, industrial and residential uses, by your local utility. Additionally, AC is affected by losses or resistance differently than its DC counterpart. All of these (and more) reasons reduce the cost of providing electricity to buildings and homes.

If the utility generated and delivered DC, then electrical devices would be set up for DC connections. Since there is 60 Hertz AC at your outlet, the CRT makes use of it, and converts it to whatever the internal requirements are. Stepping the voltage down and / or changing to DC (inside or outside the cabinet) allows for many parts of the circuit to work directly - and AC of nearly any frequency (not just 60 Hertz) can be produced as needed with electronic circuits inside the cabinet.

Colors, shading, etc on CRTs are the result of an electron gun at the back of the CRT. The gun fires electrons at tiny red, green and blue phosphorous targets on the front of the screen. When the target is struck, the phosphorous glows briefly. If the phosphorous is behind a red mask - it glows red (the same holds tru for green and blue). This same process occurs for each of the thousands of colored target on the entire screen, 60 times per second.

This is simplified explanation - there are other parts of a CRT. There are circuits that create magnetic fields the direct the electron both left and right in addition to up and down the screen. Without these circuits, there would be just one dot glowing on the screen. There are circuits for refresh rate, demagnetizing, brightness, contrast and more.

I hope this provided a good starting point for you and found it helpful.

Sounds like Generator mode switch should be "ON".

http://www.cumminsonan.com/locator The A1 controller is likely suspect.

I install and work on these everyday. If you hooked up the transfer switch you probable have a control wire wrong. check the utility power sense wire. That lets it no when to start in auto. it could be a relay or fuses. or a control board.