Many larger Grady-Whites including the 300, 330, 336, 375 and 376 have two electrical power systems: Direct current (12V DC battery power) and alternating current (120V AC shore power or generator systems). Safely and efficiently using these systems is simple, yet requires some basic understanding of how they work and how to use them properly. This article covers simple basics of the electrical systems panel box and electrical loads. Later articles will cover the DC (direct current) and other systems in more detail. Take a look at Eric Sorenson in the below video as he shows how to use the panel box aboard the Express 330; other boat models with like systems operate similarly. Also note that while this video communicates the basics, there's no substitute for reading and understanding the details in your Owner’s Manual.
AC (alternating current system)
- The boat’s electrical system is divided into two sides on the main electrical panel in the cabin: on the left are controls for the 120 volt AC systems (just like systems in your home), and on the right are the 12 volt DC controls. A voltage and amp meter is clearly visible on the panel so you can monitor loads.
- AC power comes from shorepower when the cable is plugged in at the dock, and from the generator when out on the water. Make sure you don’t try to start up too many loads at once as both generator and shorepower capacity is limited to the noted amp loads. (See your Owner’s Manual for amp information on various electrical devices.)
- The 4kW generator that Grady-White currently installs is rated for 31.6 amps continuous and 35 amps peak (up to two hours). Shorepower capacity is 30 amps. (The 8kW generator and two shorepower systems on the Express 360 roughly doubles the load capacity; check your Owner’s Manual.)
- When shifting between shore and generator power, make sure to shut off the systems first.