Moving A/C devices from one leg to another

370Dancer said:
Agreeo on all that. Prior to looking at the schematic for the pump relay (I'm still using the old Cruisair one that came with the boat), I was concerned that there might be some neutral sharing in the relay box. Looks like they are isolated enough that it won't matter. I am inclined to put the pump power on the Accy blank in the panel to overcome the issue of only running the fwd air, with the aft air breaker off = no seawater. Most people probably don't control their A/C on off by the panel breaker, but I do. It's at eye level and easy to read. The Marinaire thermostats........not so much for these old eyes.View attachment 147563
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I get why you are using a breaker as a switch but modern marine AC units like to be shut down at their thermostats. Most new units run the fan after it is switched off for a while to help dissipate the heat from the unit.

Add to that ......keep a few breakers as spare because they will wear out much faster than a switch.
 
PlayDate said:
I get why you are using a breaker as a switch but modern marine AC units like to be shut down at their thermostats. Most new units run the fan after it is switched off for a while to help dissipate the heat from the unit.

Add to that ......keep a few breakers as spare because they will wear out much faster than a switch.
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True about the shutdown. Point taken.
Well, I am learning to just use the wireless remote...... Plus, I have a Switchbot hub monitoring the cabin temp and controlling the units remotely. I ordered a couple of soft starts this morning. Couldn't hurt the situation.
 
PlayDate said:
I get why you are using a breaker as a switch but modern marine AC units like to be shut down at their thermostats. Most new units run the fan after it is switched off for a while to help dissipate the heat from the unit.

Add to that ......keep a few breakers as spare because they will wear out much faster than a switch.
Click to expand...
Here in Fl the A/C systems run 24/7. Plus I have the fans set to run at a reduced speed when the system isn't cooling. I think it is essential to continuously circulate air through the boat to prevent mold and unpleasant smells. So when not at the boat I set the temperature up to 78 degrees and let it rip.
 
At least you are getting rain. I can't catch a cloudy day here........index is 106-107
 
So, while I'm waiting for the soft starts to arrive, who has actually put one on your own system? I am surprised to see exactly ZERO vids, or even discussions on doing this to a marine unit. And that's across the interweb as I can see it.
Plenty on home units, and RV units. I might be doing the first one, but I'll need a stunt double better looking than I am.
 
Speaking for myself......I have only replaced them on residential AC units and added one to a RV Coleman AC that ran off a generator.

What I learned is that it does help with the start draw (cuts it in half).....that's it. That helped the generator get over the start hump on the Coleman AC. If memory serves me right it dropped the start draw from 8 amps to 4 amps on the Coleman.

That's not the problem you are chasing. It certainly will help if you decide to run on your generator but won't make much difference with shore power once you have rebalanced the load.
 
PlayDate said:
Speaking for myself......I have only replaced them on residential AC units and added one to a RV Coleman AC that ran off a generator.

What I learned is that it does help with the start draw (cuts it in half).....that's it. That helped the generator get over the start hump on the Coleman AC. If memory serves me right it dropped the start draw from 8 amps to 4 amps on the Coleman.

That's not the problem you are chasing. It certainly will help if you decide to run on your generator but won't make much difference with shore power once you have rebalanced the load.
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I agree it won't solve the problem he's having now. It would allow him to keep all the wiring intact while upgrading both units to the larger sizes though, which would make the upgrade a lot simpler. If the surge currents on both units were dropped they could both run on a single 30A (it's actually likely they could without the soft-starts, but they give additional buffers).
 
Agree, run amps is the culprit, not surge. But, there are occasions where I am at a less than stellar power stand.
I'm still after the redistribution of load, but just weaseling this project into all the others happening right now as I prep for being able to run amuck again after 2 years......
 
Starting current isn't typically a problem with hydraulic magnetic circuit breakers like we have in out boats. Typically they can take overcurrent situations for a second or two without tripping; see the chart below. The issue is the stress on the equipment when the equipment can't get the current needed to start. Wire size and length is the main contributor to undercurrent issues.
Cseries_Rocker_CB.jpg
 
done. Hell of a time finding the right neutral so I could move that too. Grounds are all bonded to one terminal strip, so nothing to do there. Added a breaker to the blank spot, and wired the A/C pump to that, so it is always energized, regardless of the breaker position on the aft A/C.
Put soft starts on both, which will make the Genny very happy.
 
This is full running draw on both legs without the water heater and stove on. Hardly ever use those anyway. Start surge not getting to 25 amps on either leg.
IMG_0212.jpeg
 
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