Generator install

[colemj]

Originally Posted by a64pilot

I'm familiar with how Caps are made and why they work, just seems about the only thing that can happen to a cap is the insulation break down?

Possibly. They run very cool until toward their end of life when they start to run warm. When they finally go, they are pretty hot.

Again, ours seems to be the only one that has this issue. Others tell me they need to replace the cap every couple of years or so - and they run it much more than we do.

I have somewhat systematically tried caps from different manufacturers, price ranges, etc - some have been priced like gold and come in fancy packages, while others have cost me $5 and handed to me out of a bin on a street corner. They all seem to perform exactly alike.

Mark

[socaldmax]

Originally Posted by colemj

Possibly. They run very cool until toward their end of life when they start to run warm. When they finally go, they are pretty hot.

Again, ours seems to be the only one that has this issue. Others tell me they need to replace the cap every couple of years or so - and they run it much more than we do.

I have somewhat systematically tried caps from different manufacturers, price ranges, etc - some have been priced like gold and come in fancy packages, while others have cost me $5 and handed to me out of a bin on a street corner. They all seem to perform exactly alike.

Mark

Is it mounted in a high vibration area? Perhaps remote mounting might help.

[colemj]

Originally Posted by socaldmax

Is it mounted in a high vibration area? Perhaps remote mounting might help.

It is remote mounted, and mounted onto foam/HD soundproofing material - so pretty free of vibrations even though the area itself doesn't have any vibrations. The area it is mounted in is at ambient temperature with forced airflow, so it isn't hot.

Nextgen mounts the capacitor right inside the generator head itself, which is about the most vibration it can encounter, as well as pretty hot.

Again, ours seems to be the only one I have run across with this issue. I suspect it is something particular with our wiring, panel, equipment, etc, although I haven't been able to figure out what yet. I ran all new 6AWG triplex wire from the gen to the panel (~15'), most of the equipment that we use regularly has been changed out for different brands/models with no effect (that wasn't why they were changed - lightning did that), the panel is a custom Paneltronics that is in excellent condition, and we don't run the genset at full-load (typically at 50%).

On the other hand, it means once or twice a year I have to spend 1.5 minutes slapping in an $8 part - so I am not spending a lot of time troubleshooting anymore.

Mark

[a64pilot]

My experience with large AC Caps is start and run capacitors, Start caps are much higher capacitance, but are not 100% duty cycle, Run Caps are of course 100% duty cycle, but the capacitance is much lower.

[socaldmax]

Originally Posted by colemj

It is remote mounted, and mounted onto foam/HD soundproofing material - so pretty free of vibrations even though the area itself doesn't have any vibrations. The area it is mounted in is at ambient temperature with forced airflow, so it isn't hot.

Nextgen mounts the capacitor right inside the generator head itself, which is about the most vibration it can encounter, as well as pretty hot.

Again, ours seems to be the only one I have run across with this issue. I suspect it is something particular with our wiring, panel, equipment, etc, although I haven't been able to figure out what yet. I ran all new 6AWG triplex wire from the gen to the panel (~15'), most of the equipment that we use regularly has been changed out for different brands/models with no effect (that wasn't why they were changed - lightning did that), the panel is a custom Paneltronics that is in excellent condition, and we don't run the genset at full-load (typically at 50%).

On the other hand, it means once or twice a year I have to spend 1.5 minutes slapping in an $8 part - so I am not spending a lot of time troubleshooting anymore.

Mark

As long as you don't get too high/too low voltage out of the gen, I guess there's no harm in it. Sure makes me want to put an oscope on it and see what is going on! At first some problems seem mysterious. When you finally discover the source of the problem, it always makes sense!

[colemj]

Originally Posted by a64pilot

My experience with large AC Caps is start and run capacitors, Start caps are much higher capacitance, but are not 100% duty cycle, Run Caps are of course 100% duty cycle, but the capacitance is much lower.

These are run capacitors. For the 5.5kW head, they are 40uF.

Mark

[colemj]

Originally Posted by socaldmax

As long as you don't get too high/too low voltage out of the gen, I guess there's no harm in it. Sure makes me want to put an oscope on it and see what is going on! At first some problems seem mysterious. When you finally discover the source of the problem, it always makes sense!

The voltage out of the genset is controlled by the capacitor.

I put a scope on it and posted the results in another thread here.

No doubt this will make complete sense once I determine the cause, and I will feel very stupid indeed.

On the other hand, did I mention that I have to spend 1.5 minutes one or two times a year to replace an $8 part? It is killing me not knowing why this is happening, but not enough to spend a lot more time on it!

Mark

[BobH260]

Mark, sorry about my confusion on the SOC. When you said "they are below 75%" I assumed you meant SOC of 25 % ! That is, the bank was down below 75%. My mistake.

[QUOTE=colemj;Our flooded batteries soak up 110A when they are below 75%, and keep sucking that for half an hour before falling to 85A or so. By the time they get down to only accepting 50A, I turn the charger off and let the solar take them to float. Usually I shut the charger off when the batteries are only taking 60-70A.

These flooded batteries accept the same amount of charge from our HO alternator.

A typical 0.25C charge rate for 440Ahr of flooded batteries is 110A…

Mark[/QUOTE]

I'm no expert on this stuff obviously but I thought they recommend max 10 to 13 % of C charge rate for flooded cells and 5 C for AGMs in bulk. It seems you are running much higher than that if I understand that you have flooded cells.

As far as a battery charger size is concerned I think Trojan and Maine Sail are recommending chargers in the 10 to 12 % of C range. So I think 50 A for our 400 Ahr bank maybe about right.

A couple of comments about the NextGen. Ours ate the mixing elbow when it was about 2 years old, it was replaced and has been fine since then, 4 years. So I guess they fixed that problem.

With regard to capacitors dying prematurely, I would put a oscilloscope on the generator output waveform. It may not be very clean. This could cause a capacitor to die an early death, just a quick thought. I've read that small generators often have a dirty output. An appropriate filter might fix the problem if this is the cause. I intend to put a scope on ours when we get back on the boat and see what it looks like. If there is a dirty output it would not be good for a lot of the 110v electronics on board.

We only use our boat in the winter months in Florida and Bahamas. We don't use the AC much and I don't remember ever with our generator. Usually on the hook we have good ventilation and enough of a breeze we don't need the AC. Doing so would probably extend its life by giving it a good load. We tend to run it in the morning with our battery charger, electric kettle, induction hot plate and microwave doing breakfast, plus charging our computer and phones etc. really never gets a big load for any extended time period. We could not justify replacing the on board diesel generator for our use so would go back to our Honda EU2000 if this one ever fails.

Bob

[colemj]

Originally Posted by BobH260

I'm no expert on this stuff obviously but I thought they recommend max 10 to 13 % of C charge rate for flooded cells and 5 C for AGMs in bulk. It seems you are running much higher than that if I understand that you have flooded cells.

We have flooded cells. The recommended battery chargers are for minimum charging, not maximum. In other words, Trojans recommend getting a charger in the 10-15% range so that you have a minimally large enough charger. Too many people have 1000Ahr banks with 20A chargers.

As far as a battery charger size is concerned I think Trojan and Maine Sail are recommending chargers in the 10 to 12 % of C range. So I think 50 A for our 400 Ahr bank maybe about right.

Again, minimum - they are most concerned with not having a figurative trickle charger hooked to the bank. If one cannot bring the charge state up on a bank in a reasonable time, then charging will not be completed and the bank will die an early death over time.

Batteries are internally regulated as to the amount of current they will take. For any given voltage, you can't force more current into them than they will accept. FLA's generally accept ~0.25C - a bit more or less depending on individual banks, age, temp, etc. Charging at this rate is not a problem unless the batteries have issues and are gassing excessively or getting hot. Temperature compensation on the charger helps prevent this.

If you have AGM's, and they recommend a 5C charging rate, then you should have a 2000A battery charger, not a 50A. BTW, that 5C charge rate is hooey - you won't find AGM's that will accept that rate for more than a minute or two. Mostly in practice, AGM's perform similarly to FLA's in charging profile.


A couple of comments about the NextGen. Ours ate the mixing elbow when it was about 2 years old, it was replaced and has been fine since then, 4 years. So I guess they fixed that problem.

We were warned about this - others told me theirs lasted one year. Ours is now 4 years old and has quite a bit of rust around the welds and flange, but no leaking yet. I have a custom SS one made from Schedule 40 with electropolished welds ready for when it goes.

With regard to capacitors dying prematurely, I would put a oscilloscope on the generator output waveform. It may not be very clean. This could cause a capacitor to die an early death, just a quick thought. I've read that small generators often have a dirty output. An appropriate filter might fix the problem if this is the cause. I intend to put a scope on ours when we get back on the boat and see what it looks like. If there is a dirty output it would not be good for a lot of the 110v electronics on board.

I put a scope on ours and posted the results on another thread on CF. Too lazy to look it up, but it is there if you want to see what it looks like under various types of loads.

We only use our boat in the winter months in Florida and Bahamas. We don't use the AC much and I don't remember ever with our generator. Usually on the hook we have good ventilation and enough of a breeze we don't need the AC. Doing so would probably extend its life by giving it a good load. We tend to run it in the morning with our battery charger, electric kettle, induction hot plate and microwave doing breakfast, plus charging our computer and phones etc. really never gets a big load for any extended time period. We could not justify replacing the on board diesel generator for our use so would go back to our Honda EU2000 if this one ever fails.

Bob

Similar to how we run ours also, except I keep a load on it with the 120A charger, water maker and water heater (if needed). Rarely AC - maybe a dozen times in the past 6 years at anchor.

Mark

[Pelagic]

On the exhaust side of installation I highly recommend using a "Gen Sep" as shown on post 3 Northern Lights

it dramatically quietens down the discharge noise to be almost silent from the cockpit

Your neighbours will appreciate it as well.

[HappyMdRSailor]

Originally Posted by a64pilot

If anyone is interested, this is the old Gal, I bumped into this video after having bought her.

Nice bud!