When
- Thread starter pumpkinpie
- Start date
I think the best practice is to disconnect shore power, but I have started my engine several times without disconnecting and nothing blew up.
Greg
Greg
I have never seen any problem with this, going back 30 years. We do this regularly.
There are different charger units on boats, some old, some newer & like mine, some digital.
The safest way is to insure your charger is knot charging when engine starting/running.
Why risk safety?
The safest way is to insure your charger is knot charging when engine starting/running.
Why risk safety?
I switch off the Xantrex smart charger if plugged in b/c, apparently, the external voltage regulator on the Balmar alternator does not like a second voltage regulator in the system while it’s supplying voltage. So, one voltage regulator running at a time. Either the Xantrex, the solar, or the Balmar.
If I run my genset with battery charger (pretty much the same as shore power) and the auxiliary at the same time I get an alarm on my auxiliary. No harm done, but my auxiliary doesn't like the higher voltage of the charger.
Check your owners Manual or here if you don't have it..
HunterOwners.com downloads
I did a quick look and the Starter Battery and 120VAC system are separated.
The previous owners could have made a modification so it is good to check it out. Otherwise, AC and Motor are no worries.
Jim...
The Circuit that runs the air conditioning is completely separate from anything the engine is tied in to.
The engine and alternator are connected to the DC electrical system not the alternating current (AC) system. The one cross over point is the battery charger that is running on AC is putting DC current into your batteries while the alternator is also trying to do the same.
Battery chargers are supposed to have protection built in to prevent damage but to be safe just switch the battery charger off.
The engine and alternator are connected to the DC electrical system not the alternating current (AC) system. The one cross over point is the battery charger that is running on AC is putting DC current into your batteries while the alternator is also trying to do the same.
Battery chargers are supposed to have protection built in to prevent damage but to be safe just switch the battery charger off.
My Freedom 20 I/C has automatic transfer switching built it. That prevents Generator from back charging Shore power.
Unless the PO added a Engine alternator House Battery charger.
Also I suspect yours is standard Hunter design to keep Two Alternators [Genset and Engine] from fighting each other.
Those two have an "Isolator" when they are charging the Start Battery.
You might have the Switches on your panel, labeled "Start and House".
Jim...
@pumpkinpie
I just ran across this electrical layout for the H 38
https://www.marlow-hunter.com/wp-content/uploads/h38ServiceManual120105.pdf
It shows that the Starter Battery and the House Battery are separated.
Jim..
It will depend on the capacity of the battery bank that is being used to start the engine. A well charged bank that has enough oomph to start the engine should not cause any issue with the charger. At worse it might increase the draw on the charge for a few seconds and blow the fuse. That won't be an issue if the charger is fused properly at the battery connection.
To avoid conflicts between the Alternator, Charger, and solar, have each one set at a slightly different bulk charge voltage. The primary source, the most used source should be at the highest voltage, the least used or weakest should be the lowest. The devices with the lower voltage set points will not charge when a higher voltage device is charging. So, if the charger is set at 14.9 v and the alternator at 14.8, when the engine is started the alternator regulator will see a voltage of 14.9 and ramp down the alternator output. Of course this only works if you can program the charger and the alternator regulator.
To avoid conflicts between the Alternator, Charger, and solar, have each one set at a slightly different bulk charge voltage. The primary source, the most used source should be at the highest voltage, the least used or weakest should be the lowest. The devices with the lower voltage set points will not charge when a higher voltage device is charging. So, if the charger is set at 14.9 v and the alternator at 14.8, when the engine is started the alternator regulator will see a voltage of 14.9 and ramp down the alternator output. Of course this only works if you can program the charger and the alternator regulator.
Shore power is 120/250 v. and is not wired directly to an engine which is generally 12v. My first reaction to the question is to study the basic electrical systems on a boat, particularly those with both 12v and 120v. This knowledge will save you time and money. Not having this information at the dock is not nearly as important as not having it away from the dock.