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Emergency generator??

Discussion in 'Electronics' started by richierich33, Nov 7, 2023.

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  1. richierich33, Nov 7, 2023
    #1
    richierich33

    richierich33 New Member

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    2006 Lazzara 74 has a 27.5kw main gen and a 13.5kw “emergency generator”. This unit has a separate isolated circuit within the panels to only run a few critical items like batt chargers, refrigerator, lighting and 220vac emergency bilge pump. (way less than it's capability) Seems like a waste of a capable gen to me. Looks pretty easy to convert this to a “nighttime generator” to run 50amps of whatever I choose (half the AC, TV, etc). The question is why did Lazzara set it up this way and can there be any down side to this unit having an option to power anything (within ampacity) in the panel? Thanks
  2. butch w, Nov 20, 2023
    #2
    butch w

    butch w Member

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    I would think that running it like you say as a nighttime generator and on a load would be good for it.
    I am not an expert by any means, but

    Worse thing is for it to sit un-used not running at all and hoping it will run fine when needed in an emergency. It is also good for the generators to be ran under a load, if it were mine I would absolutely run it and power on what it can run.
  3. Capt J, Nov 21, 2023
    #3
    Capt J

    Capt J Senior Member

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    I have no idea WHY Lazarra set it up that way and was puzzled at some of the things it didn't power, I think fresh water pump was one of them. I'd convert it so you can choose to run whatever you want on it, as it's oversized for the little stuff it did actually run and no reason to put any hours on it except in an emergency
  4. mapism, Nov 21, 2023
    #4
    mapism

    mapism Senior Member

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    Why, isn't that 24V DC?
  5. Pascal, Nov 21, 2023
    #5
    Pascal

    Pascal Senior Member

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    Usually on the smaller boats Lazzara used an AC pump (Mach 5) with a 24 Vdc backup.
  6. Capt J, Nov 21, 2023
    #6
    Capt J

    Capt J Senior Member

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    Ask Lazarra, but the way they did the backup generator is incredibly stupid. You would never run it (not even as a night time generator) because it won't even power the things necessary to live on the boat even with the HVAC off. It only will power 1 panel out of 4 electrical panels in the boat and only certain items are on there and those are the ONLY things you can access with the little generator running. The little generator at 13.5 kw is oversized for just that panel. If you could send the power to the main electrical panel where the other gen power is accessed you could run a few ac's off of it, or whatever you want and more items. I had an owner that was highly interested in a 68' we looked at a few and even sea trial/surveyed one of them, which is how I came across this weird generator situation.
    richierich33 likes this.
  7. richierich33, Nov 21, 2023
    #7
    richierich33

    richierich33 New Member

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    The "emergency" 13.5kw does run to all the AC panels but like you said it only runs a few items in each panel. I'm looking for a way now to combine the two but a small portion of the schematic is faded.

    Attached Files:

  8. Capt Ralph, Nov 21, 2023
    #8
    Capt Ralph

    Capt Ralph Senior Member

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    Those prints are just fair.
    You select the gen-set by rotary transfer switch? At each panel or a single switch somewhere?
    Your in North Florida when, for me to fix it for you?
  9. richierich33, Nov 21, 2023
    #9
    richierich33

    richierich33 New Member

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    By transfer switch which again the schematic is vague as to how it wires in. I believe in the pic below the transfer switch is referred to as "emergency loads breaker" (which is only a portion of the transfer switch) more importantly, what isolates these emergency loads from the rest of the panel.

    Attached Files:

  10. Capt Ralph, Nov 21, 2023
    #10
    Capt Ralph

    Capt Ralph Senior Member

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    First SWAG, your second gen-set if only 115Vac.
    Have to re-strap it for 230Vac and tie all in like your #1 gen-set.

    Your in N FL when??
  11. richierich33, Nov 21, 2023
    #11
    richierich33

    richierich33 New Member

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    SWAG?? The second is also 230VAC (has to 115VAC legs), simply paralleling the outputs would be easy enough but I'd think they'd still need to separate though the transfer switch. We'll be in St Augustine around Christmas.
  12. Capt Ralph, Nov 21, 2023
    #12
    Capt Ralph

    Capt Ralph Senior Member

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    SWAG;
    Scientific Wild Asp Guess..

    I think I see what is going on.
    Some easy mods can fix this mess.

    The prints in post #7 show some the restrictions in service.

    Pic and print in post #9 threw me off a few seconds.

    I have metric and SAE hammers just for these occasions.
    Last edited: Nov 22, 2023
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  13. mapism, Nov 22, 2023
    #13
    mapism

    mapism Senior Member

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    If the two genset are close enough each other, it might be easier/quicker to parallel the two outputs with a 3-ways disconnector in between, for putting either one or the other on line as desired, but never both.
    This way, you wouldn't need to fiddle with the electrical panel, which could be left on Line 1 at all times.
    Of course, you should "self-limit" the loads when you're running on the smaller genset, but that would be true even with a more sophisticated integration.
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  14. BlueNomad, Nov 22, 2023
    #14
    BlueNomad

    BlueNomad Member

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    It's set up that way for regulatory compliance, as certain 'vital' loads are required to have two independent power sources.

    The genset provides 240 Vac to port+stbd blowers, fresh water pump and emergency bilge pump. It provides 120 Vac to engine room lights, battery charger #1 and galley panel emergency loads which are detailed on sheet 3 (not shown).

    The down side to rewiring in order to power anything in the panel is that it's then possible to overload this genset such that it is not available for vital loads when required. It is not as oversized as it might appear and must be sized to run all connected loads simultaneously.
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  15. richierich33, Nov 22, 2023
    #15
    richierich33

    richierich33 New Member

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    What if I simply removed the protection slider from the (Gen 1-Gen 2) transfer switch allowing both breakers on at the same time? That should parallel everything with zero wiring change, right?

    What’s the worst case of overloading the 13.5k, the breaker trips? Having run the whole boat on one leg of a 100amp splitter many times I can say 50amps is still a good bit of power. It should be ideal for a nighttime generator when we’re off the grid for long periods.
  16. Pascal, Nov 22, 2023
    #16
    Pascal

    Pascal Senior Member

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    The easiest way is probably to run the 13.5 output to a selector (rotary or double breaker with slide) in the ER that would select gen 1 or gen 2

    Remove the slide on the existing selector is a disaster waiting to happen.
  17. Capt Ralph, Nov 22, 2023
    #17
    Capt Ralph

    Capt Ralph Senior Member

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    Is this a charter or commercial boat? In the US?

    [QUOTE="BlueNomad, post: 348973, member: 87753" It is not as oversized as it might appear and must be sized to run all connected loads simultaneously.[/QUOTE]
    We have a 30 & 9kw gen-sets.
    Sometimes we forget to turn the water heater breaker off at night.
    When the double element water heater kicks on with a couple of ACs running, everybody on board knows it.
    Lights dim, gen-set moans out loud and if somebody does not turn an air conditioning unit off quickly enough, the lil gen-set grinds to a halt.
    In all these years, never hurt a thing.

    I think (hope) better units have an AVR that unloads the field when over loaded.

    But depending where / what straps are modified for richierich33, leave his water heater(s), galley oven or other loads off of the smaller gen-set.
  18. Pascal, Nov 22, 2023
    #18
    Pascal

    Pascal Senior Member

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    Which regulatory compliance? ABYC? Never heard of it. There are many boats with single gen…
  19. Capt Ralph, Nov 22, 2023
    #19
    Capt Ralph

    Capt Ralph Senior Member

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    Suddenly a Darwin candidate.
    Never handle a bomb without it's safety devices.
  20. BlueNomad, Nov 22, 2023
    #20
    BlueNomad

    BlueNomad Member

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    Nice quote CR.
    You must never remove the interlock. Multiple AC sources cannot act in parallel without aligning phases, not an easy or cheap thing to do. For vessels of this size and complexity ensuring that only one source can energize the panel at any given time is non-negotiable.
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