Back up for farm, house, Air BNB
This web page is intended to be instructional for the limited users of the farm / house setup and informational. WARNINGS are clearly posted at the site and the two individuals who might be using the system have been instructed on the step by step instructions.
Generator is patched into the main house breaker panel with a 60A double pole breaker. This is not a proper transfer switch and must be properly managed by keeping the transfer breaker off whenever the MAIN breaker is on. This process is usually done by a single double pole switch that prevents the two circuits from ever being connected at the same time. This is a compromise between affordability, safety and the need for a back up power source. The system will be upgraded accordingly when I have the resources to do so.
If you want to leave comments, do so respectfully and in order to provide useful commentary. Understand that, I do know about wiring, dangers, risks, etc and may have more experience, knowledge and years of electronics, high voltage & high power systems including the burning up untold quantity of very high voltage and high power electrical devices through experimentation.
- Grid active, Generator connected, running or not – damage to the generator vs breaker trip.
- Grid active, Generator connected, running or not – fire hazard at the generator.
- Grid active, Generator not connected – creation of a electrical shock hazard at the male end of either the 240V NEMA wall receptacle or the generator extension cord if connected. The male ends of such plugs are normally never energized but would be energized in this case.
- Grid inactive, generator connected and running – generator overload due to it’s connection to the grid.
- Grid inactive, generator connected and running – if no generator overload, grid becomes electrified by the generator posing electrical shock risk to those who may think it’s off.
- Grid inactive, generator connected and not running – no immediate risk until either becomes active then see above.
I have experimented with #1 and #2 with an older generator running and not running. There was never any apparent damage. It results in an instant breaker trip of either the transfer breaker or the generator breaker. In a couple of cases, the generator sync’ed up with the grid! Not the recommended way to sync two AC sources but if they are not too much out of phase then they will sync. I don’t recommend trying this, but . . . FYI.
Default Conditions for Home Powered by Grid:
- MAIN breaker – ON
- Transfer breaker – OFF
- Specific circuit breakers – as desired – mostly all ON
- Extension cord from generator – DISCONNECTED – doesn’t really matter but this prevents accidental exposure of generator to grid power if active grid is unintentionally connected to the generator power socket.
- Generator – OFF
Generator startup and power transfer sequence may be used for:
- Restoring house power during power failure.
- Testing power transfer sequence or exercising the generator.
Power transfer – Grid to Generator – exact sequence may not be critical, but some elements are critical.
- MAIN breaker – turn OFF (down position)
- Verify Transfer breaker is in the OFF (LEFT) position
- select individual circuits to be powered by turning off (OUTSIDE POSITION) high power circuits. See FIVE breakers below in photo marked with YELLOW.
- Connect 240V generator power cord from generator to the generator port on the wall.
- Begin generator startup sequence.
- Crankcase oil is sufficient (don’t always need to check this)
- Generator fuel tank is sufficiently full. Else add ethanol free, stabilized fuel as needed. Fuel cap is tough to turn. Feels like it’s stuck. Just keep twisting harder to open.
- Generator ON / OFF switch is in the ON position (leave this in the ON position and stop the generator by cutting off the fuel valve unless there is a need to quickly stop the generator. Then turn this switch back to ON so it’s ready to start the next time.
- Fuel valve – move to the ON or VERTICAL position.
- Carburator choke – verify or move to the START or LEFT position
- Pull the starter rope to start generator.
- Generator will run rough with smoke while choked. You should be able to quickly move the choke to the run position. If the generator stops, turn the choke back to start and repeat the rope pull.
- Main breaker – verify that it is in the OFF (down position)
- Transfer breaker – move to the ON position – house is now energized from the generator.
Power transfer – Generator to Grid
- Transfer breaker – move to the OFF (LEFT) position
- Generator Fuel Valve – move to the OFF (HORIZONTAL) position – generator will run for about a minute but meanwhile . . .
- Remove generator power cord from the wall port
- Remover generator power cord from the generator after generator stops running.
- Move choke to START position in preparation for next startup.
- Turn individual breaker circuits back to ON (MIDDLE) position except for hot tub, for example.
- Verify transfer breaker is OFF (LEFT position)
- MAIN breaker – turn ON (UP position)