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Hybrid generator – remote control

Reading time 5 minutes

Updated – April 18, 2023

Remote control of a hybrid generator with an electric start function is often offered by the manufacturer, but the prices for this option are usually corresponding.

In motorhomes, the generator is usually installed in the rear garage. If you don't like slobbering around with gas, you'll leave the gas tank empty and run the generator with gas.

In gas mode, however, the choke must be operated when starting and, after the generator has started, it must be changed again according to the instructions for use.

Since the generator is encapsulated to reduce noise, access is difficult. In addition, the generator generates a lot of process heat, which can also be dissipated via adequately sized ventilation arrangements, including a cross-flow fan mounted on the upper air outlet in the side wall of the motorhome.
The ignition key to start the generator could still be replaced using a button located on the inside, but you can only access the choke lever directly on the generator, of course only after removing the surrounding housing, etc. Creative skills are required here, if you want to just – start the generator.

If you use Homematic / RaspberryMatic in your motorhome anyway, you can use it to control the generator and use the internal (radio) button or cell phone / tablet to start the generator, have the choke operated automatically and then switch the generator off again.

materials

are needed

cabling

Relay and generator ignition/starter function

The cabling is moderate. The make contacts of the two relays, one for “ignition OFF” and one for “starter ON”, are switched in parallel to the generator key switch.

The relay coils are connected to vehicle ground with a common ground. The plus line of relay I “Starter ON” is connected to the left screw terminal (7) of channel 3. The plus line to relay II “Ignition OFF” is connected to the left screw terminal (9) of channel 4 of the 4-way switching actuator.

Key switch modification

The key switch of the K&S generator KS 3000 G has four connection cables (counting on the back of the switch from left to right):

  • 1 – yellow-green (Rel. II, Kl. 30)
  • 2 – black (Rel. II, Kl. 87)
  • 3 – white (Rel. I, Kl. 30)
  • 4 – black and white (Rel. I, Kl. 87)

1 and 2 short-circuit the ignition (relay II, terminal 30 / 87), so that the generator is switched off, 3 and 4 (relay I, terminal 30 / 87) switch plus to the starter to start the generator.

4-fold switching actuator and PWM forward/reverse controller

The two right screw terminals (8 and 10) of channels 3 and 4 are connected to the PWM forward/reverse controller's "Power +" screw terminal (4) (far right). The plus voltage supply for the 4-way switching actuator from the screw terminal (1) (“+” – outside left) is also routed to this connection. The negative line from the screw terminal (2) (“-” – right next to it) of the 4-way switching actuator goes to the screw terminal (3) “Power -” of the PWM forward/reverse controller, as well as to vehicle ground . The positive voltage supply to the controller and the 4-way switching actuator, which is also powered, takes place via a 2 A fuse in the plus line via a connection to the general voltage supply of the motorhome.

Fig. – 4-way switching actuator terminals/buttons
Fig. – Terminal PWM controller

Pushrod motor

The push rod motor is connected to the two screw terminals (1) minus and (2) plus of the PWM forward/reverse controller.
The standard position of the push rod motor is extended (for choke position LPG start-up phase).

The push rod motor is attached to a suitably curved aluminum U-profile with an M6 screw. The push rod is also provided with an M6 screw and a pressed-on aluminum profile into which two M3 screws are screwed, secured with lock nuts, to programmatically move the choke lever back and forth.

Modification to the PWM forward/reverse controller

Since the push rod motor used here requires around 10 seconds to travel its maximum distance of 5 cm, the potentiometer connected to the PWM controller can be removed (unplug the ribbon cable on the potentiometer board), connections 1 and 2 (white and red, interrupted). long dashed line) short-circuited (equal to “switched on”), and lines 3 and 4 (white, widely dotted and red, broken in medium length) are also connected to each other (PWM switched off, correspondingly unreduced speed).
Alternatively (loss of warranty!), the corresponding pins (1 and 2, as well as 3 and 4) can be bridged directly on the board with a drop of solder and the cable can be pulled out of the socket on the board.

Fig. – Bridged pins 1/2 and 3/4 at the bottom left

Dry run

Switch on the PWM forward/reverse controller on the potentiometer. Then test the function of the four relay channels on the 4-way switching actuator. Pressing the button

  • 1 – Extend the push rod motor
  • 2 – Retract the pushrod motor
  • 3 – Starter relay energize
  • 4 – Ignition relay energized

If all four functions have been successfully completed, the Homematic / Raspberrymatic control can be programmed.

Create variables

For visualization using AIO Creator and remote control via cell phone/tablet, the following variables (spelling/case sensitive) must be created:

  • Gen_AUS of type Logic value (default: true)
  • Type Gen_Choke List of values (LPG_START;LPG_OPERATION;LPG_OFF)
  • Gen_Start of type List of values (START;OPERATION;OFF)

Name devices/channels

The channels of the 4-fold switching actuator are given the following names in the following programs:

  • Channel 1 – HG_SW_III_K1_Choke_Operation
  • Channel 2 – HG_SW_III_K2_Choke_Start
  • Channel 3 – HG_SW_III_K3_Gen_Starter
  • Channel 4 – HG_SW_III_K4_Gen_ON_AUS

Create programs

You only need to create two programs:

  • SV_Gen_Aus – is activated when the status of the variable changes Gen_Out on true started
  • SV_Gen_Start – is activated when the status of the variable changes Gen_Out on incorrect started

Program SV_Gen_Start

The variable Gen_OFF is default true. This is done, for example, by pressing the button I (Switch on) is pressed in the AIO Creator visualization on the cell phone/tablet, the command to change to the logic value is activated incorrect sent to the Homematic / RaspberryMatic headquarters.

This change starts the program SV_Gen_Startto start the generator.

channel 4 of the 4-way switching actuator immediately switches on the ignition of the generator. At the same time, channel 3 will allow the starter relay to energize for 5 seconds to turn on the generator and start the generator (the second value can be adjusted as required).

A second later the variable Gen_Start on BEGIN set to provide the visualization with a yellow label (for “Generator starts”).

After 10 seconds, channel 2 of the 4-way switching actuator is activated for 5 seconds (the running time for the middle position of the push rod actuator (corresponding to the choke position “LPG operation”)).
The subsequent switch-on command starts the specified time cycle of 10 seconds switch-on time.

Immediately, however, the variable is used for visualization purposes Gen_Choke on LPG_Start set to return to status after 10 seconds LPG operation switch. Likewise, the status of the variable Gen_Start 10 seconds later Operation changed.

Program SV_Gen_Aus

By pressing the visualized button 0 (Turn off) becomes the command to change the variable Gen_OFF to the logic value incorrect discontinued.

The ignition of the generator is immediately interrupted by switching off channel 4 of the 4-way switching actuator.

When channel 1 is switched on, the push rod motor is moved back to its starting position for LPG operation for 5 seconds (the value can be adjusted if necessary).

5 seconds later the variable Gen_Choke on LPG_START, – immediately – however, the variable Gen_Start on OUT OF set to update the visualization.

Visualization

Using AIO Creator, the visualization of the generator operation was integrated into the other visualization interface:

Fig. – Generator condition.

Between the two keypads there are two LEDs arranged vertically one above the other. The top one shows the status of the choke setting (yellow = ready for LPG start), the lower one shows the status of the generator (gray = Out of).

Functional test

Finally, before installation, a functional test: