Thread: 240/120v switch
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Old 08-15-2022, 09:57 PM   #1
chasles22
Veteran Member
 
City: St Pete
Vessel Name: Cavalier
Vessel Model: Cheoy Lee LRC 61'
Join Date: Jun 2022
Posts: 26
240/120v switch

Howdy. I bought a boat, my first big'un. I'm trying to unwind how the electrical system works. Consider me smarter than the average bear when it comes to electronics and electrical systems... Yet I'm befuddled. What does the switch in the attachment do? Some info/assumptions...

The boat takes a single 50a shore power to run everything

The boat has 2 generators each 15kw which can only be connected to the boat one at a time (not paralleled.

When I turn the switch to 240 (on the hard in the boat yard) it shows appx 210v (assuming they have 3 phase power and this is accurate). When I turn it to 120v it shows appx 120v.

So what the heck does this thing do? Is this just a Europe 240v on a single line switch so in North America it should always be on 120v?

The issue is that previous owner had it on 110v and everything was working fine on shore power. Then we pulled out to take it to yard and air conditioning wouldn't work on generator (kept popping dual pole breaker). Just a point of fact. Then in the yard the batteries started to drain and weren't charging even with shore power. A yard guy change the switch to 240v.... No one seems to know why.
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