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Note: The comments page has been very active lately. Thus, I split it into multiple parts. To see the older comments, look here, or, HERE And, even older comments can be found: HERE.
If you have any comments on this website, or just want to send Ken a message....
The Nordhavn 62, Great Pearl, that you saw is the same boat that we crossed the Atlantic with in 2004. We were supposed to be cruising Alaska together this summer, but my boat is still stuck in Costa Rica. Our run to Japan next year will be Grey Pearl, Starr (a Northern Marine 75) and ourselves. -Ken W
Comment by: Visitor (7/2/2008 12:48:57 PM) Whale Song was featured in the most recent (August 2008) issue of Passagemaker Magazine. Perhaps they could put you in touch with the owner.
On another note, I saw N62 Grey Pearl yesterday northbound near Lund, BC. Interestingly, there is also now a N55 named Grey Pearl that I saw a few weeks ago outside of Pender Harbour. Good luck with the Japan via the Aleutians trip, it sounds quite ambitious but a lot of fun.
Ted: I responded to you here:
http://nordhavns68.talkspot.com/aspx/blob2/blobpage.aspx/msgid/463430/beid/6332
- Ken W
I think going over to a three phase boat would involve new generators, a new Atlas unit and a major rewire. At the end of the day it would not solve the high start up current problem. Your best solution is converting the airconditioning compressors to a soft start system.
Changing the subject the motor yacht Whalesong made the trip from Dutch Harbour to Japan last year. They only have one sentence on the trip across the Bering Sea (rough) but do give some insight to the problems of getting into Japan. No doubt they could give you further information.
Their site is http://www.mywhalesong.com/
The site is a little flaky when navigating around at the moment, a more dirct link is
http://web.mac.com/jbfoto/WS_Logs/East_Asia/Archive.html
Ted
Comment by: Visitor (6/26/2008 7:47:27 PM)
Ken,
Sounds like a good alternative to research. I am unfamiliar with "Technicold". I, like you have seen hundreds of CruisAir systems. The only things that raises my attention is the "Dumb-beast" functioning. Having serviced large tonnage chilled water plants the simplistic systems need an onsite technician to monitor the plant to prevent failures. Imagine the chilled water loop losing a hose, without a safety feature to shut down the compressors problems quickly cause catastropic failure. I personally like the computer interface. Regardless of the compressor brand the most complex feature you are introducing are the VFD's. These are serious machines that are not serviced by just anyone. Some build up voltages in the capacitors over 10,000 volts. Not to deter you but again I like the systems with logic to help monitor. I love the setup you are introducing, currently I am designing something similiar for my home using ground water heat transfer.
As far as the generator I am sketchy on the details. In commercial buildings we don't have inverters, Atlas systems or batteries. We do have backup generators but that is direct load transfer from the grid.
JC
JC: It's good to hear I'm not totally nuts, and others have had the same issue. As to the chillers, the leading idea is to go with a completely different brand of chiller. I was at Lugger a couple of days ago and looked at a chiller they have just started selling, from a company called "Technicold". I don't know much about it, other than the size fit nicely, and the unit looked super-simplistic. I currently have four 36,000 BTU units. The unit I saw at their office was a 60,000 btu unit, and I could get away with two of them. It was a super-dumb beast. You have one control to set the low, and the high, loop temp, and then an on/off. It looked like something I could fix, whereas the Cruisair intimidates me (which is funny to say, because I'm a super-techy guy). I may not need a screen for the a/c system. This seemed really simple. I'll put two of the units, and put a breaker for each on the electrical panel. I can run one or two, units, simply by flipping the on/off switch, and make the decision based on power available. With soft start, having two come on at once isn't a big deal. The 60,000 btu unit said that it uses 16 amps. That would be awesome, and handle the boat 99% of the time. I will also look at what Cruisair has, but space is a huge issue for me. The larger cruisair units don't seem to fit where I need them. If I do swap to a different brand for the chillers I'll still use the Cruisair air handlers, circ pump, and cooling pump.
As to the generator. I'll ask. All of this is a bit over my head. Wouldn't I also need to swap my other generator, and the inverters, and make changes to the Atlas? So that everything is three-phase?
-Ken W
Comment by: Visitor (6/26/2008 5:50:13 PM)
Ken,
That wasn't hard, I found the link for the CruisAir software. http://www.cruisair.com/TWLCinstall.html
Hope it helps
JC
Comment by: Visitor (6/26/2008 5:45:49 PM)
Ken,
Wow, I haven't read your website in a few weeks and it seems you are really tackling the HVAC issue. You mention that you are replacing the chillers with the new 3 phase comp's and installing vfd's to drive them to the desired load. Are you also going to install CruisAir's computer interface? I believe this allows some monitoring (maybe you could remotely monitor and adjust the chilled water loop temperature for example) and adjustment. Also if your getting a new generator why not upgrade to a 3 phase generator. This would allow you to run the compressor in a pinch if the VFD's fail with what is referred to as a bypass contactor. I do this all the time in HVAC loads for commercial buildings. Look at the start and run load amps for the 3 phase units, amazing how different they are from single phase. By the way where is the dumpster you are throwing all the old "junk" into? ;). One more thing, you are not the only one with this issue. Your just one of the few who have a platform for us to hear it. Manufacturers have been saying "Your the only example we have ever heard with this problem" for years. Good Luck with everything.
JC Jannarone
My Outback inverters do not have an option to use the batteries to supplement the generator, and handle the surge. Victron's newer inverters do offer this as an option. I asked Outback if they planned to add it as a feature, and they said they had no plans. One possible solution is to swap out my inverters for Victron. My current thought though is to reduce the number of inverters. I need to do something to free up some space in my lazarette, and reduce complexity. My current plan is to reduce the number of inverters, cut the size of the battery bank, go with soft start chillers, and increase the size of my 16kw generator to 20kw (they are the same form factor). Basically, I'm going to convert it to a boat which requires the generator to always be running when away from the dock. This has pros and cons, and can be argued for hours... I did see your comment about using the PTOs to provide power hydraulically. I currently have hydraulic alternators that can give me 500 amps of 24 volt power. I'm not sure this couldn't be fixed, but currently my testing shows that they are increasing the engine fuel burn by more gallons per hour than using the generator. Electrical systems are so much fun! -Ken W
Comment by: Visitor (6/26/2008 2:20:50 PM)
the puzzling part is why your batteries aren't taking up the surge. this is essentially victrons strategy. they suggest using a smaller generator and use the batteries to take start up loads. some boats size the generator for start up loads which means its under loaded a lot of the time. as for running a/c on too few amps, i'd try asking cruisair if you can upgrade to 3 phase chillers, the only difference on the drawings is the size of the electrical box, then install a cruisair vfd. then challenge an electrical engineer to balance the boats loads, if you 40 amps available, have the system up the a/c temp from say 72 degrees to 76. good luck! :) jon
Jon: You've asked an interesting question: "Why is no one else having this problem?" It's not an easy answer. The spec sheet for my chillers identify them as having a 12 amp current requirement and a 100 amp "locked rotor amperage." In other words, even though the chiller only uses 12 amps after it is running, it takes 100 amps to get it moving.
Now, let's look at my current situation: The boat is essentially shut down, in preperation for shipment. Almost nothing is running on the boat. However, I can only get 50 amps of power from shore power. Actually it is worse than that. I can only count on about 40 amps from the marina shore power. Let's assume that my boat is currently consuming 3 or 4 amps for the few things that are running. Thus, there should be 36 amps available to service the air conditioning. The problem is that 36 amps is not adequate to provide the 100 amps of start-up current required to get the chiller running. The boat's electrical system is made to accept high loads for very short periods. Sometimes, the chiller fires up quick, and sometimes the shore power breaker blows. Sometimes fuses blow.
The reason this usually isn't an issue is because the answer is simple: If you don't have adequate current to run the air conditioning, don't run the air conditioning. My guess is that Cruisair would be the first to say that I can't reliably start up my chiller with only 36 amps available. One way to solve this problem is with more current. 100 amp service is a solution when it is available. Running the large generator is a solution. Another solution is to swap my chillers for alternate chillers that don't require the high startup load.
To accomplish soft start, I need to swap to three phase chillers. My boat is a single-phase boat. The good news is that soft starts (called Variable Frequency Drives) are available that accept single phase input, and drive a three phase chiller.
The bottom line is that: the current chillers can be made to work, but only by providing plenty of power, and recognizing that the lights will dim from time to time, as the chillers spin up to speed. I'm trying to find a solution that allows me to operate the a/c in tight current situations. If my boat were spending most of its life sitting in a modern marina, in a fairly moderate climate, this would be a smaller issue. -Ken W
Comment by: Visitor (6/26/2008 2:54:36 AM)
correction! the vfd can run on 1 or 3 phase but needs a 3 phase compressor to work. single phase seems to draw more amps at start up than 3 phase. jon
Comment by: Visitor (6/26/2008 2:27:04 AM)
ken, seems a strange problem (a/c) only because no one else seems to experience it and cruisair is used by enough people you would think someone would post something, somewhere with the same problem. cruisair does sell a variable frequency drive to cure the problem you are having. the only thing i have read that could cause problems like yours is single phase output. soft start requires 3 phase to work. jon
Comment by: Visitor (6/26/2008 1:29:39 AM)
Jon: I haven't yet spoken to Victron, but I did hire an electrical engineer consultant to evaluate what they have, and sent him the specs for their inverters. We just met, for a couple of hours, last week to go through his findings. The bottom line seemed to be that Victron would be a big step forward from where I am. Specifically, the Victron inverters have an option to supplement a generator, by inverting from the batteries, and then combining the power from the generator with the inverted power from the batteries. My interest is in using this ability to handle the short spikes caused by the air conditioning chillers cycling on.
However, since that time, I've made the command decision to dump my existing chillers and buy new ones, with soft start. I should point out that Nordhavn (and, probably many others) think I am crazy to do this. Nordhavn continues to insist that they can get my chillers working fine with a few hours of effort. My only response would be that I've lived with these chillers for a year, and I have read their technical specifcations. It is physically impossible for these chillers to start without a huge amount of current (60+ amps). It may be possible to tweak my electrical system such that it can survive brief periods of excessive amperage, and lowered voltage, but I just don't want to do that. There are soft start chillers (chillers that do not require massive amounts of current to bring up to speed), and they really aren't that expensive (as compared to the cost of the boat). I'm making the command decision to make a change.
The current overload, as a result of the air conditioners, is only one of two problems I've focused on this week. The other one is the frequent power failures at Golfito, in Costa Rica. I do have auto-start on one of my generators, but it works differently than I need. This is easily fixed. I just never realized it was an issue until I had the boat to a country with poor electricity.
I will contact Victron. I also will be calling Atlas tomorrow, and am now following up with a company called Woodward, which was a referral from someone else on this board. My goal is to use this winter to get the boat as close to perfect as I can get it before we start our circumnavigation next summer.
On a vaguely related topic: I was reading my book, yesterday, about the run to Costa Rica and realized that it is an awesome book. However, I can't take the credit. The real value in the book is not my comments, but the letters I received while cruising. For whatever reason my blog, and website, seems to have collected an amazingly intelligent group of followers. I hope that people who read my blog (or the book) take the time to read the "letters to Ken" -- they're the real meat of the book, and the primary reason I do the blog. I've learned more by doing this blog, than by anything else I've done! - Ken W
Comment by: Visitor (6/25/2008 11:30:48 PM)
check out victron energy also. this company has done a lot of work into creating electronic systems that work together seamlessly. they wrote a great paper on combining shore power, generator, batteries and inverters for different types of boats. they may also be willing to suggest a strategy for you. jon
Comment by: Visitor (6/25/2008 9:27:11 AM)
Jason: Thank you for a great lead. This seems to be the company:
http://www.woodward.com/power/easygen-300.cfm
Currently, my boat does have auto-start on the generator, but it is wired strangely. It was set up such that the sole use of the auto-start is in an "at anchor" situation. It strictly watches battery voltage, and kicks in the generator only if it sees low voltage. I actually used this mode for a couple months when my shore power adapter (Atlas) failed.
I'll study the Woodward website, and report back on what I find. - Ken W
Comment by: Visitor (6/25/2008 5:22:19 AM)
Ken,
I was reading your recent blog entry that described power failure issues on Sans Souci. I was surprised to hear that your boat is currently unable to automatically start/stop generators on loss of shore power. While I don't have any idea about your current electrical set up and generator controls (and what would be required to integrate a new control), you may want to consider installing an "easYgen" control for your generators. It's a Woodward powergen product that is widely used with diesel prime power and standby power requirements. This control is considered a utility grade control and is very powerful. It offers a HUGE number of features and capability but in general it can monitor "shore power" and when power is lost it can automatically start generators and bring them on-line. When power is restored it will shut-down generators and re-connect vessel with shore power. It also offers full monitoring and protection of the engine/generator as the genset is brought on-line. In addition, it is network capable so you can connect remotely to the control through the web to monitor and adjust any parameters. I will send you an e-mail with a spec sheet detailing the control.
Jason
Chuck: I've never heard of schedule F breakers. I think you are referring to breakers that are slow to blow, so that they aren't tripped by spikes. I do have commercial breakers.
My problem is that it literally takes 75 to 100 amps to start my chillers, versus only 12 amps when they are running. My 16kw generator only puts out about 65 amps. If the normal house (hotel) load is 20 to 30 amps, then the 12 amps to run a chiller is fine, but the 75 amps to get it running isn't. Most chillers only have high demand for less than a second. The models I have are new to Cruisair, and the start-up seems to take multiple seconds. This is long enough that the generator has time to lug down, and the voltage drops. Sometimes the shore power breakers trip at the pedestal, and sometimes it's the breaker inside my boat. Other times, it's fuses blowing in completely different circuits, because the amperage surges as the voltage falls. I need chillers which don't have the high current surge, or at least have a faster startup. Maybe. I am going to give Nordhavn a chance to fiddle with my electrical system, but expect I'll be ordering new chillers.
-Ken W
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