I recently installed a Xantrex Pro-1000. I hard-wired it to all of my port & stbd AC outlets since everything I plug in I typically would like to use underway. Shore power currently only supplys a 10 amp battery charger and one outlet.
The inverter has a transfer relay to transfer loads from shorepower to inverter and vice versa automatically. The question is, if I hard wire the invert to shore power how many times is the AC grounding wire going to be connected to my boats ground? There is a chassis ground on the inverter separate from the inverter DC negative. There is also a grounding wire connected to the shore power inlet.... If I hard wire the inverter to shorepower it seems like I will have created two ground paths. Everything I have read has made it very clear that shore power grounding wire should be connected to ground on the boat only once. Would it be a good idea to cut the shore power inlet grounding wire? Hmmm....
First off, it would be a really bad
idea to cut the shore power inlet grounding wire. If you do this, when connected to shore power, a phase-neutral fault (short) on the dock could electrocute anyone on board who happens to be using anything you have that's got a hard-wired earth (ie. not double-insulated).
If the inverter has a transfer switch, you connect the shore power to the Inverter AC input and the AC output directly to your AC distribution panel.
1. Connect the chassis ground on the Inverter to your boat's grounding point (engine mount, keel bolts, whatever). This is probably also your DC ground, but it is important that you have two
separate connections (AC gnd & DC gnd) to the same point on the boat to avoid ground loops - it's called a "single-point ground".
2. Connect the Inverter AC output (phase, neutral & earth) to your AC panel.
3. Connect the shore power ground socket earth pin to your AC panel earth bar and nothing else.
Since the Inverter's AC ground pin should be connected to the chassis internally, the AC ground path is then from your equipment -> AC Ground bar -> Inverter chassis -> hull (and shore power ground if you're connected).
I hope I haven't confused you..