NW Explorations
DREAM CATCHER OPERATING MANUAL
|
25
4F2: AC Inverter System
The Inverter Makes AC from DC...
As we said, the Inverter system is used to provide AC to the boat when there is
no shore power. It is wonderful, for example, to use the inverter to make a pot
of coffee when the engine is running and you are underway, or to watch TV in
a quiet anchorage, or use a hair dryer for a few minutes in the morning. But
for long- period use of AC by large appliances, the engine or generator must be
running or you must have shore power available.
Now the microwave, for example, will draw about 50 amps of DC when using
the inverter to run it, so in six minutes you use one-tenth of an hour at 50
amps, or five ampere- hours. That’s okay. But what if you want to cook a roast for 30 minutes? You would use up a lot of
energy on that one job alone! That’s too much use for the inverter, and the propane stove or oven should be used.
For a short task, the inverter is great: no starting the generator, no noise, no fuss, the power is there. If the engine are
running, use it all you wish, as long as you don’t try to do two huge jobs at once: The inverter produces a maximum of
2,500 watts of energy at a time. So the inverter
is only wired to
the refrigerator, icemaker, Webasto furnace circulating
pump, AC outlets, and the microwave
. It will not run the water heater, battery chargers, washer or dryer.
...It is also a Battery Charger, Making DC from AC!
The Inverter can also do the reverse: If there is AC power available from a shore-side
source or the generator, it can recharge the house batteries. The battery charger
function receives that power through the “Inverter Battery Charger” breaker on
the AC panel. Since this breaker must be “On” for the batteries to charge using AC
power, and you will want to charge the batteries at every opportunity, we suggest
that you leave it “On” for the duration of your cruise.
As noted above under the “Connecting Shore Power” section, be mindful that
the Inverter can draw a lot of current when charging the batteries, especially when first activated upon connection to
shore power. Thus, you need to be careful not to overload a shore power circuit
by running other high-draw AC appliances at the same time. Monitor the AC Ammeter to make sure the load remains
below the available current as determined by the shore power service from the marina, normally 30 amps.
Inverter Operation
The inverter is controlled by a single button with a light in it (see illustration just above). The light indicates the inverter’s
status.
BUTTON LIGHT SHOWS
MEANING OF BUTTON LIGHT
Steady
Inverter is
making AC from the batteries
Blinking Slowly
Inverter is
charging the batteries
Blinking Very Rapidly
Inverter is
not charging, and nothing is using it’s AC-making capability
No Illumination
Inverter is Turned “OFF”
Remember the important note above under “Connecting/Disconnecting Shore Power”: The inverter, if on, will draw a lot
of current when bulk charging, so be careful not to overload a shore power circuit.
In summary, the inverter should be on whenever shore power is present or the generator is running, and it may also be
left on when underway. It is a good idea to leave the Inverter on all the time, being cautious to turn off at their breakers
any equipment which might run the batteries down when you are not tending the boat; in this way, you will run critical
equipment but reduce the risk of running down the house batteries just because someone left some AC appliance
plugged in and forgotten.
Note: Only the breakers in the panel illustration on page 4.10 with an asterisk (*) are powered by the inverter!
The Inverter, port side of the Engine Room.
Inverter control button to right of lower helm.