MJM Yachts 34z Express - Manual (Page 23)

CHAPTER 6 ELECTRICAL SYSTEM
- 23 - 34z
The house battery switch can be left OFF when the boat is not used, and the batteries will still
accept a charge from the battery charger. If you are leaving the boat plugged into shore-power
and you wish to turn off all DC loads but still be able charge batteries. Leave the house switch ON
and turn off the main DC disconnect breaker on the DC panel.
In the event of a dead or weak engine battery, the parallel battery switch can be used to combine
the house bank to the engine start bank. All three switches must be ON for this function. This is
recommended only as a last resort- if shoreside or genset charging is available, use that to re-
charge the start batteries. DO NOT LEAVE THE PARALLEL SWITCH IN
THE “ON” POSITION.
6.3
AC SYSTEM (Optional)
The AC system exists to power such items as a Cooktop, Microwave, Entertainment System, AC
Outlets, Air-Conditioning and Water Heater. There are three ways to supply AC power to these
appliances/systems [See Figure 14.4]: (1) You can plug one or two 30-amp shore power cords
into a shore-power supply, depending on which items you want to power; (2) the generator can
be used; or (3) the house batteries can supply DC power to the Inverter which converts it into AC
power. The main AC disconnect breakers (top of the AC panel) must be ON for shore-power AC
to supply the boat’s AC power. There are two AC Breaker Panels: AC PANEL #1 (forward)
includes breakers for those items which can be handled by the Freedom 30 Inverter. To use the
inverter, (1) the house battery selector switch must be ON and (2) the inverter breaker on the AC
panel must be ON. Refer to the inverter/charger manual for more information
AC PANEL #2 Because your batteries would not last long supplying high amperage water heater
or air-conditioning systems, these items CANNOT be powered by the inverter and are therefore
isolated on the aft #2 AC Panel which is directly fed by a separate shore power cord that by-
passes the inverter.
When the Shore 1 shore-power cable is
attached and the Shore 1 select breaker is
ON, Shore 1 will supply AC power to AC
Panel #1 (forward side of panel). With the
inverter ON, the shore-power will override it
and the inverter will automatically go into
stand-by mode. When the Shore 2 shore-
power cable is attached and the Shore 2
select breaker is ON, Shore 2 will supply AC
power only to AC Panel #2 (aft side of panel)
which is for air-conditioning and water heater.
If a second shore-power receptacle is not
available and you have not operated the boat recently, there won’t be any hot water. Simply shift
the single cord from the Shore 1 receptacle aft to the Shore 2, flick the hotwater breaker on, wait
15 minutes and your shower will be ready.
If the generator (optional) is being used in lieu of shore-power, the Transfer Select switch (on
the AC panel) can allow either Shore 1 or the generator to power the AC Panel #2 circuits.
However, if this function is utilized, the owner must be aware that using too many AC appliances
at once will cause a breaker to blow. Avoid using major appliances simultaneously while using
the Transfer feature.
As mentioned, the generator (optional) can be used to create AC power. The generator battery
selector switch must be ON and the generator must be selected on the AC panel. Refer to the
manufacturer's manual for more information regarding the generator.