Next gen 5.5 kw- can I run it 12 hours straight?

[malbert73]

Hi everyone-
As we cruise the chesapeake in the summer heat, I am wondering if we need to keep up our habit of running genset in evening to cool down cabin x3-4 hours, then shutting down and sleeping under fans.
Any reason we should avoid running it all night? It's not a continuous rated generator, but runs at 2800 rpm rather than 3600 so pretty calm and quiet. I think it's kubota engine is same as most refrigerator trucks run constantly to keep their contents cool. It's in our lazarette and well cross vented by a forced air blower. Just don't really know what "intermittent" means. I always thought 3-4 hours at a time but this is based on nothing empiric.

Thanks all!


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[Tkeeth]

I dont have any experience with that genset, but intermitent to me means it isnt the main power source 24/7. I run my genset (koehler) for 12 to 18 hours all the time. Just check the fluids and make sure everything is good. Most have some sort of protection circuits if it starts getting hot it should shut down.

[Stumble]

I really can't think why you can't run it all night. But if you find a reason let me know, we have been running one for weekends at a time for years.

[malbert73]

Originally Posted by Stumble

I really can't think why you can't run it all night. But if you find a reason let me know, we have been running one for weekends at a time for years.

Cool- you have a nextgen also? How many hours?


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[RaymondR]

Usually when things are rated as intermittent it means they have a duty cycle where the gadget can be run at full load for say 5 minutes then requires a cool down period before being run at load again however it could also be a life of unit sort of rating where the life of the gadget is specified as so many years if it is only run say 2 hours per day.


I'd run it under load for a fairly long period keeping a close eye on the temperature and if it does not get excessively hot you are probably going to be OK. If it's a life time rating thing you are going to have to replace it more often.

[Ericson38]

http://www.cruisersforum.com/forums/...ew-155713.html

[Stumble]

To clarify, we do not have a Nextgen system, but another 'intermediate' rated generator.

I think you misunderstand what duty cycle means. It doesn't mean the engine needs to be turned off every so often, it is simply a rating on how much of the time the engine is rated to operate at 100% of its rated maximum output. So a 'continuous' rating means the engine is rated to operate a 100% of its output 100% of the time, 'intermittent' is generally 100% of its rated max load 50% of the time. Or max load for 30 minutes per hour.

With generators this happens close to automatically due to the difference in the start up versus operating loads of the consumers.

If your primary consumer is AC, the thermostat that cycles the AC on and off will easily keep the generator below its rated duty cycle, if it could stress it that hard in the first place.

[a64pilot]

I've run my Nexgen 3.5 overnight pretty often.
My typical load is 21 or so amps, about 70% of max. The intermittent rating means that I should not run it at 30 amps continuously due to heat build up, it is not meant to determine engine run time, but how long you run it at full output.
My 3.5 and your 5.5 have the same generator head, what limits mine is engine HP, what limits yours is I believe the generator head and heat build up, if it's in a sound proof enclosure, the more air you can get through that enclosure, the happier it will be.
On mine I replaced the cheap corrugated plastic hose it came with, with smooth aircraft Scat hose. With the factory supplied hose I was having the CB trip due to heat build up in the enclosure.

It's my understanding that getting several thousand hours out of these little generators is not uncommon, they are not as long lived as say a low speed heavy duty one, but they are smaller, and lighter and less expensive.

Give Nexgen a call, they are very helpful and will explain things to you.


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[singlespeed]

We have the same unit on our boat. Anchored far up the river, across from Oriental, NC, during Hurricane Irene. Shut off the wind instruments at 52 knots and turned on the genset for the next 24 hours and watched movies. The genset has performed well since.

Before the peanut gallery takes off, wearing a dive mask, snorkle and tether, check for chafe on both anchors every half hour.

[malbert73]

Very helpful everyone. I really didn't know what duty rating meant. Since my AC is a single 16k unit, sounds like I can run it constantly overnight whenever I want. Don't actually know how many amps the Ac drAws but am sure a lot less than 45 (5500w / 120v)


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[malbert73]

Also my genset is in a fairly large lazarette with cross ventilation from a blower so seems to stay cool. Lazarette is sound insulated so tight soundshield not needed....


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[a64pilot]

A 16K AC unit will pull with its water pump between 10 and 15 amps, my old one pulled 14, my new one 11.
But you hit the nail on the head, your capable of 45 amps output, if your an average 40ish sailboat, you may have a 30 amp boat, one single 30 amp shore power cord.
If that is true, then you really cannot overload your generator as if I do the math correctly 30 amps, the boats limit is only 66% of the generators output.

On edit, I run both my AC's most of the time, one 16K and a little 5K, combined with a little battery charging I pull 21 to 22 amps, continuously, out of a Nexgen 3.5, which of course is smaller than yours.


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[wesevans]

Yes you can.

[TheThunderbird]

My Fisher-Panda type8 is rated for continuous 70% of nominal rate of 7,3kw

Only "heavy duty" can run 24/7
PLEASE CONSIDER TO TAKE LOAD OFF BEFORE SWITCHING GEN ON/OFF, to avoid electric damage on utilities

...

My Q is:

Given the enclosure, and the engine room, which benefit would be to increase ventilation?
In summer, engine room reaches 60+℃, not good for any engine to breath in..

[J Clark H356]

I have no experience with a NexGen but have a 36 foot Hunter with 16k AC, KVH tracking antenna, TV, Dish box and run computers, IPads, IPhones, Microwave, HWH, Inverter/Charger and never strain the unit. It is a heavy duty unit and when on shore power on one cord, I will trip boat breaker - 30 amps when Hot Water,Microwave and HVAC are all under load. Doesn't strain the Northern Lights. We run our 5 KW (41.6) continuously when not at the dock. You have a lot of diversity. All of the connected load is generally not running at the same time, so if you are concerned, just turn off something that has a high load like hot water heater before going to bed and let the generator run all night. We have around 3070 hours and are on our 14th season. We have run continuously while cruising a maximum of 99 hours (just over 4 days) with no problems and would run it twice that much if needed without thinking about it. I consider my limit the amount of fuel I have on board, not the generator run time. I burn about 6 gallons of fuel in 24 hours, just under .25 gallons per hour.


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