Electrical question

[Ray Durkee]

I used the Yamaha 1000 generator extensively for the last 6 months on my cruise down through central America and the Panama Canal and it worked very well. I thank you for your advice. Very quiet (you cannot hear the thing a boat length away) and it is quieter than my diesel. In the tropics, it is a godsend as you do not want the heat in the boat from the diesel. I just set it up when I leave for shore and everything is charged up when I get back. This Yamaha is a terrific unit--uses about .1 gal per hour (runs about 6 hours on a tank) and weighs 27 pounds.

One issue: I seem to be going through engine and prop zincs at a very accelerated rate. Should I be grounding this unit to the water or is this just something that happens when you use a generator?

A cheap receptacle tester (circuit analyzer) works well.

[DeepFrz]

Ray;
I can't see any reason why your generator would be causing the accelerated aging of your zincs. I think that you should be looking elsewhre for that, unless you have grounded your Yamaha to the engine.

Check your electrical system carefully to see if you have some kind of electrical leakage somewhere. If you are in a marina you may have a neighbor that is causing some problems.

Check out the following link and go to the shore power safety tests.
http://www.proboat-digital.com/proboat/200604/

hth, Deep.

[GordMay]

Ray asked, in a PM:
Re: Gas Generator Grounding
"So even if I am not using the rest of the AC system the generator should not be plugged into the 30 amp shore power input. Is that right? ..."

I am extremely hesitant to offer specific advice regarding Portable AC Generator connections, without knowing the full extent and quality of your particular existing wiring. It should also be noted that Portable Generators are not intended for use aboard boats (tho’ I’ve happily used one for years).

1. Test your Generator to ensure that the Generator Neutral IS Bonded (connected) to the Ground.
The Neutral should be the larger of the two parallel flat blade slots, to the left when viewed with U-Ground “down” (on generator receptacle). A simple continuity test (zero ohms) will suffice.
2. Test your AC Shore Power Inlet (shore power cord removed) to ensure that the Neutral is NOT Bonded aboard the boat. Also test your boat’s receptacles for proper polarity, and ungrounded neutrals.

Given that the Boat’s AC Neutral is only grounded through the Shore Power Cable (not aboard the boat), and the Generator Neutral is Bonded to the Generator Ground (as tested above), you can safely plug your Generator AC Output into your AC Shorepower Inlet, providing Generator Power to the entire AC Distribution Panel. This ensures that:
1. You only have a single Source of AC power connected (shore OR generator)
2. You only have a single Neutral Ground point (either at Shore or Generator).

You will have to make up a Generator Power Cord, with a Female end to match your boat’s shore power inlet configuration.
Notwithstanding the configuration (perhaps 30A Twistlok?) of your generator cord, you will only have about 800 Watts (6.7 A) of power available from your 1000W generator.

HTH,
Gord

[JohnWms]

"Also test your boat’s receptacles for proper polarity, and ungrounded neutrals."

Just to clarify, I should get open circuit between the ground hole in an AC receptacle and the boat's DC ground? Same with the neutral (large) hole?

[GordMay]

Yes, with Shore Power & Generator disconnected there should be NO continuity between any of the three sockets.
With Generator connected (to inlet), but NOT running, there should be continuity, between Neutral & Ground.
With power "on" there should be 120V between Hot & Ground or Neutral, but NO voltage beteeen Neutral & Ground.

[DeepFrz]

Your AC and DC ground should be connected in one spot, at your main ground bus.

[ssullivan]

My genset (5KW diesel) is set up just like Gord describes, and I'm seeing no quick zinc disolves. I would strongly suspect something other than the genset itself. Theoretically, you should have had the exact same problems when connected to shore power as you would when running the genset.

Possibly you are experience faster zinc loss due to your cruising grounds??

If you went from SF to the area you mention, you will be in much warmer and saltier seas then the ones you are used to. This results in a much faster zinc loss.

[hvolkhart]

Do I look at the correct diagram?

L5-30P

X = Black = Hot/Line = Large flat connector
W = White = Neutral = small flat connector
G = Green = Ground = connector with angle flap