Coming off shorepower

[firecadet613]

When your about to head out for the day, how do you switch from shore power to the genset power?

Power everything down, switch to genset power, and then power it all back up? Just throw the switch?

 

[Southpaw II]

1. Turn off any 120v items running on the boat (A/C, HWH, etc.)
2. Turn off the pedestal breaker(s).
3. Disconnect the power cords from the boat.
4. Crank the generator. After it warms up, start turning stuff on as needed.

Don

 

[Bucit]

1. Turn off any 120v items running on the boat (A/C, HWH, etc.)
2. Turn off the pedestal breaker(s).
3. Disconnect the power cords from the boat.
4. Crank the generator. After it warms up, start turning stuff on as needed.

Don

+1 shut everything down, power up the genny, let her warm up and then start power the 120v items back on.

 

[Aguyindallas]

1. Power down all 120V items.
2. Turn off shore power switch on the panel.
3. Start Generator
4. Upon warm up, begin turning back on the 120V items needed.
5. Disconnect shore power

I do not turn off the power at my shore power pedestal...is that really needed?

 

[Alex F]

I guess this is one of those things we all do slightly different.

I don't always use my genny when I take off the dock, but when I do my steps are:
1. Start the genny and let it worm up.
2. When I'm ready to switch the power I shutdown sensitive components like TVs and A/Cs (if they're on). I don't flip individual breakers and I don't shutdown HWH. However, doing it by the book would mean flipping each breaker.
3. I flip the main shore power breaker at the control panel. Then, I also flip the main breakers in the stern locker (this is more for power switch when I'm back to a slip).
4. Since I leave most individual breakers ON I turn only one side to genny power. I wait for about a minute and then turn ON the 2nd side. This is to avoid "shocking" the genny with a load all at once.
5. I turn on the equipment which I had turned off before switching.

 

[firecadet613]

Thanks. Just wanted to confirm that shutting it off and bringing it back up one by one once under genny power is the way to do it.

 

[Jetmart]

1. Power down all 120V items.
2. Turn off shore power switch on the panel.
3. Start Generator
4. Upon warm up, begin turning back on the 120V items needed.
5. Disconnect shore power

I do not turn off the power at my shore power pedestal...is that really needed?

Shutting off at the pedestal is definitely necessary if your leaving the shore power cord plugged in and on the dock. If it is ever knocked in you got live power in the water. I know the breaker is suppose to trip but I have seen breakers fail and fuses not blow when they are suppose to.

 

[JimT]

1. Start the genny and let it warm up
2. Turn off 120v breakers.
3. Turn off shore power on breaker panel
4. Unplug shore power cord from pedestal. I don't flip the breaker. I take the power cord with me.
5. Switch over to genny on breaker panel
6. Turn 120v breakers back on

 

[src]

Think of it this way. If there were a problem with the shore power cable/connector, would you rather find out about it with your hand on the cable, or with your hand on the breaker?

 

[sdarc]

Think of it this way. If there were a problem with the shore power cable/connector, would you rather find out about it with your hand on the cable, or with your hand on the breaker?

BINGO!!!!:thumbsup:

 

[fwebster]

I guess this is one of those things we all do slightly different.

I don't always use my genny when I take off the dock, but when I do my steps are:
1. Start the genny and let it worm up.
2. When I'm ready to switch the power I shutdown sensitive components like TVs and A/Cs (if they're on). I don't flip individual breakers and I don't shutdown HWH. However, doing it by the book would mean flipping each breaker.
3. I flip the main shore power breaker at the control panel. Then, I also flip the main breakers in the stern locker (this is more for power switch when I'm back to a slip).
4. Since I leave most individual breakers ON I turn only one side to genny power. I wait for about a minute and then turn ON the 2nd side. This is to avoid "shocking" the genny with a load all at once.
5. I turn on the equipment which I had turned off before switching.

Alex,

The reason you should turn off all the breakers isn't to "avoid shocking" the generator, but rather to protect the individual circuits on the boat. A generator isn't a power source like ConEd where you have 120/240VAC available all the time. When you dump a large load on the generator all at once, the voltage drops a little. It really doesn't matter for lights, an idle microwave or coffee pot, but you don't want the refrigerator, icemaker or anything with a pump in it to start with say 100VAC as the generator rpms drop off due to loading. So, why not just turn off all the breakers in the main panel when you go to the panel instead having to think about what you have on and whether or not it has a motor in it?

 

[rcknecht]

I guess this is one of those things we all do slightly different.

I don't always use my genny when I take off the dock, but when I do my steps are:
1. Start the genny and let it worm up.
2. When I'm ready to switch the power I shutdown sensitive components like TVs and A/Cs (if they're on). I don't flip individual breakers and I don't shutdown HWH. However, doing it by the book would mean flipping each breaker.
3. I flip the main shore power breaker at the control panel. Then, I also flip the main breakers in the stern locker (this is more for power switch when I'm back to a slip).
4. Since I leave most individual breakers ON I turn only one side to genny power. I wait for about a minute and then turn ON the 2nd side. This is to avoid "shocking" the genny with a load all at once.
5. I turn on the equipment which I had turned off before switching.

I do the same a Alex:smt038... I don't always use the genset, and typically start it when anchored. Just unplug the shore power and take off... One time I forgot to unplug the shore power and it unplugged itself abruptly:wow:... I don't have a pedestal, since I keep the boat at the house...

 

[Alex F]

Alex,

The reason you should turn off all the breakers isn't to "avoid shocking" the generator, but rather to protect the individual circuits on the boat. A generator isn't a power source like ConEd where you have 120/240VAC available all the time. When you dump a large load on the generator all at once, the voltage drops a little. It really doesn't matter for lights, an idle microwave or coffee pot, but you don't want the refrigerator, icemaker or anything with a pump in it to start with say 100VAC as the generator rpms drop off due to loading. So, why not just turn off all the breakers in the main panel when you go to the panel instead having to think about what you have on and whether or not it has a motor in it?

You're absolutely correct, Frank. This is the reason I turn all A/C units, TVs off and other sensitive equipment. I don't do the fridge and HWH. I could be mistaken, but I think that most 112vdc/110vac fridges always are wired via inverter and the voltage drop should be a big issue. We have tons of stuff on boats that use 110vac, but majority demand low AMPs. As far as I can tell only few components like HWH and A/C units are the top AMP users. On my boat each A/C unit uses close to 10amp and similar goes for HWH. My steps take this in to consideration when I turn off all the A/C units. When I flip the one side on the genny ON (I usually do port side first for no particular reason, just clockwise order) the biggest amp user that remains ON is the battery charger. It takes around 5AMPs or less. Then, after a minute or so I turn the stbd side on and a lot of times there's no load at all, but if the HWH kicks in my biggest power drop is 10AMPs. This means that in worst case scenario my genny has very light load despite the fact that most of my breakers remain ON. In regards to the small and quick voltage spike when HWH damands power when I turn on the stbd side is really not any different when let's say the genny was ON for a while and now your A/C kicks in. This produces pretty much the same voltage spike.

All and all, IMO the method I use to shift power from shore to genny is way much less stressful for the system compare to the scenario on a hot summer days when all is up and running and ALL components (HWH and both A/C units, and all other) start to kick in and genny has to deliver all 50-60AMPs. So, comparing 5-10AMPs demand when I start is very conservative compare to spikes with 50-60AMPs demand.

I've used my way of switching power all the time on my 320 as well, since for the most part the components were also 12vdc and/or 110vac, like on my 420. However, if I had a boat with 240vac system, then I would turn off the fridges and ice makers as well. So, this is another one of those "it all depends" cases, at least in my view.

I don't disagree and actually have sated in my previous post that if you want to go by the book, then every breaker should be off on any boat.

 

[Greg]

Another thing to keep in mind is that refrigeration units (A/C's and Fridge, Freezer, Slushie Machine, etc.) don't like to be power cycled quickly. So I usually turn those off (from the breaker, just cause it's easier) when I start the generator. Then when the genny is all warmed up, I flip from shore to genny and turn those circuits back on one by one, waiting a little bit between each one.

I don't usually bother turning off the breaker at the pedestal. The cord comes with me and the boat breaker is always off when I plug or unplug.

Many fridges have built in timer circuits to protect against the power cycle issue, but I figure better safe than sorry.