I haven’t posted much lately, been pushing towards getting ready to travel this month. Lots of little systems that have been started but are not finished, so no final result to post even though it’s going well. Just sticking to critical path items.

Anyway, this post is about my first Moochdocking test with items that just arrived from amazon yesterday.

As part of my DIY hydronic design, I used two RV style water heaters to hold and warm the glycol for the system.

When being used with electricity these two heaters are wired on each side of the 50AMP service plug (same for the air conditioners).

So anyway, the expected shore power scenarios are:

1. Single 120V extension cord.
2. Two 120V Extension cords to different circuits.
3. Single 120V 30AMP connection.
4. Dual 120V 30AMP connection, with 30AMP extension cord to unused camp site.
5. True 50 AMP RV service

I found the Two 120V Extension cords to different circuits solution from watching the following YouTube video: https://www.youtube.com/watch?v=80ZucqclD80

The parts that I ordered to do this are:

1 EA https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
2 EA https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

30AMP extension cords not ordered, but considering:

https://www.amazon.com/Camco-Extensi...e%2C217&sr=1-4

https://www.amazon.com/Camco-Extensi...e%2C217&sr=1-3

I really, really like the combiner cord as my first use was after dark!!! Each input leg has an LED to show that it is being fed power. The NEAM 14-50 female end had two LED's which I used as a mini flashlight to find the mating plug in one of my equipment bays.

So anyway back to some take a way’s on my hydronic system:

1. Diesel boiler runs at full power until the input temperature caches up with the output. At which point it throttles back. So, I will add an automation to detect this and automatically turn it off until the relight point is reached.

Running toward peek temperature:



After the peak:




2. The maximum temperature that the water heaters will heat to electrically is 140 degrees with no adjustment controls.


3. When running on extension cords you don’t really want to draw more than 1800 watts peaks.
The water heater's I selected pull about 1500 watts when energized. Not sure I can keep the bus warm on 3000 watts in colder temperatures, so hey another automation control option to kick the diesel boiler on when it can’t keep up.

4. My previously posted solar simulator to charge via shore power must be controlled to get under the maximum peak draw. So, if a water heater on the same circuit is energized then the power draw needs to be turned down. So, I will have the automation logic automatically turn the power draw down if the hydronic output temperature is below 150 degrees and the heater circuits might kick in.


So anyway last night I ran the diesel boiler until it reached peak (no temperature control on the interior zones yet) and then turned on both water/glycol heaters with heat distribution to all zones and left the bus Moochdocking from two 120V outlets on separate circuits.

Here are the results (note the switch over was around 8PM):



As you can see it fairly much held it's own, though it only got down to around 43 degrees last night. Just need to decide the criteria to decide when to kick in the diesel boiler assist for the automation logic.