|
One more inverter question
So, say I've got a measley 2 group 27s and my old Yanmar 2GM15 and I
want to by a 2300watt continuous inverter. BUT... I'm willing to run the Yanmar while I'm using any heavy loads like a power tool, microwave, or electric heat and I only use the inverter *without* running the Yanmar/alternator for small loads like a TV/VCR or a boombox. Any problem with that? Stephen |
Hello Stephen,
Just do the math. 2300 watts is about 200 amps at 12 volts! That's maybe 3 hp with no losses, so your Yanmar can handle it, but not many alternators will handle 200 amps continuously. What your alternator doesn't supply will come from the batteries. They'll discharge fairly quickly. Forget the electric heater. A microwave might be practical for short periods, and a power tool like an electric drill should be no problem at all. A boombox may be a small load, but a TV/VCR may not be. For a load of 120 watts, you're talking about a dc current of more than 10 amperes. Depending on the state of charge and capacity of your batteries, you could get a couple of hours of TV from them. Good luck. Chuck Stephen Trapani wrote: So, say I've got a measley 2 group 27s and my old Yanmar 2GM15 and I want to by a 2300watt continuous inverter. BUT... I'm willing to run the Yanmar while I'm using any heavy loads like a power tool, microwave, or electric heat and I only use the inverter *without* running the Yanmar/alternator for small loads like a TV/VCR or a boombox. Any problem with that? Stephen |
Comments below:
"Stephen Trapani" wrote in message ... So, say I've got a measley 2 group 27s and my old Yanmar 2GM15 and I want to by a 2300watt continuous inverter. BUT... I'm willing to run the Yanmar while I'm using any heavy loads like a power tool, microwave, or electric heat and I only use the inverter *without* running the Yanmar/alternator for small loads like a TV/VCR or a boombox. Any problem with that? Stephen Simple math. Watts = Amps x Volts So, lets say the alternator attached to your Yanmar is capable of putting out a sustained 65 amps at 14.6 volts with the engine running at, say, 2000 RPM without overheating or burning up the belt or whatever. And it can do this for as long as you want to support a heavy load on your inverter. So: 14.6 volts x 65 amps = 949 watts x 85 % efficiency = 800 watts or so. This means, if your inverter is 85 % efficient at converting 14.6 volts to 115 volts you will only be able to get enough power from your alternator through to your inverter to deliver a sustained 800 watts to whatever it is you want to run. In other words, if you run a 1000 watt electric heater (and most are 1500 watts or more) off your inverter with your engine running you will still be slowly running your batteries down. Any sustained load below 800 watts or so will run off the alternator, with perhaps a little left to trickle charge the batteries. On the other hand, if your load is intermittent, like a power tool, or microwave, it depends on how much of the time the tool/whatever is running. If it causes the inverter to draw more than your charging system can deliver it will draw the extra from the batteries but when the tool is off the alternator will charge the batteries back up. Expect more inefficiency in charging the batteries so it wont be a 1 to 1 relationship of run time to recovery time, more like 1 to 2 or worse. But it can be done and is. You should probably forget about the heater though... Make sense? -- Ken Heaton, Cape Breton Island, Canada kenheaton AT ess wye dee DOT eastlink DOT ca |
Ken Heaton wrote:
Comments below: "Stephen Trapani" wrote in message ... So, say I've got a measley 2 group 27s and my old Yanmar 2GM15 and I want to by a 2300watt continuous inverter. BUT... I'm willing to run the Yanmar while I'm using any heavy loads like a power tool, microwave, or electric heat and I only use the inverter *without* running the Yanmar/alternator for small loads like a TV/VCR or a boombox. Any problem with that? Stephen Simple math. Watts = Amps x Volts So, lets say the alternator attached to your Yanmar is capable of putting out a sustained 65 amps at 14.6 volts with the engine running at, say, Okay, so my amp meter reads somewhere around 45 amps when it is charging the battery, so I figure 45? X 14.6v? so I can expect, say 80% efficiency just to be safe, 525 watts? 2000 RPM without overheating or burning up the belt or whatever. And it can do this for as long as you want to support a heavy load on your inverter. So: 14.6 volts x 65 amps = 949 watts x 85 % efficiency = 800 watts or so. This means, if your inverter is 85 % efficient at converting 14.6 volts to 115 volts you will only be able to get enough power from your alternator through to your inverter to deliver a sustained 800 watts to whatever it is you want to run. In other words, if you run a 1000 watt electric heater (and most are 1500 watts or more) off your inverter with your engine running you will still be slowly running your batteries down. Any sustained load below 800 watts or so will run off the alternator, with perhaps a little left to trickle charge the batteries. I can tell by the amp hour rating of the batteries how long the two group 27s will hold up in this over-use state, right? How do you figure that? It will suck anything over 45 off the the batteries draining the batteries faster the higher the charge? And then if I keep running the over-use after the batteries run down, the inverter overharge alarm will go on? No big deal I can just turn off the large draw and charge up the batteries before I turn off the Yanmar? Will the 12 volt Bible cover this? I just ordered it. On the other hand, if your load is intermittent, like a power tool, or microwave, it depends on how much of the time the tool/whatever is running. If it causes the inverter to draw more than your charging system can deliver it will draw the extra from the batteries but when the tool is off the alternator will charge the batteries back up. Expect more inefficiency in charging the batteries so it wont be a 1 to 1 relationship of run time to recovery time, more like 1 to 2 or worse. But it can be done and is. You should probably forget about the heater though... One more question, is this sort of usage hard on the batteries at all? Wear them out faster or anything? Make sense? Very helpful, thank you! Stephen |
YES! That type of discharge cycle is VERY hard on batteries. Most Type
27 deep cycle batteries are good for about 280-360 discharge/charge cycles. You didn't indicate if your type 27s were deep cycle. If they are standard auto starting batteries, the cycles will be less. You should never discharge the batteries below 50% capacity. If you want to run a 2300 watt inverter, get a pair of Trojan J305HC batteries (335 Amp Hrs). a Balmar 100 Amp alternator, a three stage regulator for the alternator,a Balmar Duo-charge, and keep the 27 for a starting battery. krj Stephen Trapani wrote: Ken Heaton wrote: Comments below: "Stephen Trapani" wrote in message ... So, say I've got a measley 2 group 27s and my old Yanmar 2GM15 and I want to by a 2300watt continuous inverter. BUT... I'm willing to run the Yanmar while I'm using any heavy loads like a power tool, microwave, or electric heat and I only use the inverter *without* running the Yanmar/alternator for small loads like a TV/VCR or a boombox. Any problem with that? Stephen Simple math. Watts = Amps x Volts So, lets say the alternator attached to your Yanmar is capable of putting out a sustained 65 amps at 14.6 volts with the engine running at, say, Okay, so my amp meter reads somewhere around 45 amps when it is charging the battery, so I figure 45? X 14.6v? so I can expect, say 80% efficiency just to be safe, 525 watts? 2000 RPM without overheating or burning up the belt or whatever. And it can do this for as long as you want to support a heavy load on your inverter. So: 14.6 volts x 65 amps = 949 watts x 85 % efficiency = 800 watts or so. This means, if your inverter is 85 % efficient at converting 14.6 volts to 115 volts you will only be able to get enough power from your alternator through to your inverter to deliver a sustained 800 watts to whatever it is you want to run. In other words, if you run a 1000 watt electric heater (and most are 1500 watts or more) off your inverter with your engine running you will still be slowly running your batteries down. Any sustained load below 800 watts or so will run off the alternator, with perhaps a little left to trickle charge the batteries. I can tell by the amp hour rating of the batteries how long the two group 27s will hold up in this over-use state, right? How do you figure that? It will suck anything over 45 off the the batteries draining the batteries faster the higher the charge? And then if I keep running the over-use after the batteries run down, the inverter overharge alarm will go on? No big deal I can just turn off the large draw and charge up the batteries before I turn off the Yanmar? Will the 12 volt Bible cover this? I just ordered it. On the other hand, if your load is intermittent, like a power tool, or microwave, it depends on how much of the time the tool/whatever is running. If it causes the inverter to draw more than your charging system can deliver it will draw the extra from the batteries but when the tool is off the alternator will charge the batteries back up. Expect more inefficiency in charging the batteries so it wont be a 1 to 1 relationship of run time to recovery time, more like 1 to 2 or worse. But it can be done and is. You should probably forget about the heater though... One more question, is this sort of usage hard on the batteries at all? Wear them out faster or anything? Make sense? Very helpful, thank you! Stephen |
On Sat, 26 Mar 2005 10:40:18 -0800, Stephen Trapani
wrote: So, say I've got a measley 2 group 27s and my old Yanmar 2GM15 and I want to by a 2300watt continuous inverter. BUT... I'm willing to run the Yanmar while I'm using any heavy loads like a power tool, microwave, or electric heat and I only use the inverter *without* running the Yanmar/alternator for small loads like a TV/VCR or a boombox. Any problem with that? Stephen If I recall correctly, the stock (Hitachi?) alternator on my 2GM was only rated at 35 amps - that would only be enough to sustain a 3 amp (360 watt) load at 120 volts. (I replaced the stock alternator with a higher output unit, and a smart regulator, to give me some chance of keeping the batteries charged.) Given the small alternator, and your very small battery bank, I think the 2300 watt inverter is excessively large. In any case, I would strongly recommend doing some re-wiring so that you have a dedicated starting battery, and the inverter, and other non-engine loads, will run off separate deep cycle batteries. Forget about electric heat - it just isn't feasible with the batteries you have. The microwave, power tools (and possibly an electric kettle) are OK, as they are short-term loads, and the total ampere-hours used by them should be fairly low. The TV and boom box would be on for longer periods, but are fairly low draw, so may also be OK - but I would definitely want a separate starting battery! -- Peter Bennett, VE7CEI peterbb4 (at) interchange.ubc.ca new newsgroup users info : http://vancouver-webpages.com/nnq GPS and NMEA info: http://vancouver-webpages.com/peter Vancouver Power Squadron: http://vancouver.powersquadron.ca |
Peter Bennett wrote:
On Sat, 26 Mar 2005 10:40:18 -0800, Stephen Trapani wrote: So, say I've got a measley 2 group 27s and my old Yanmar 2GM15 and I want to by a 2300watt continuous inverter. BUT... I'm willing to run the Yanmar while I'm using any heavy loads like a power tool, microwave, or electric heat and I only use the inverter *without* running the Yanmar/alternator for small loads like a TV/VCR or a boombox. Any problem with that? Stephen If I recall correctly, the stock (Hitachi?) alternator on my 2GM was only rated at 35 amps - that would only be enough to sustain a 3 amp (360 watt) load at 120 volts. (I replaced the stock alternator with a higher output unit, and a smart regulator, to give me some chance of keeping the batteries charged.) Given the small alternator, and your very small battery bank, I think the 2300 watt inverter is excessively large. In any case, I would strongly recommend doing some re-wiring so that you have a dedicated starting battery, and the inverter, and other non-engine loads, will run off separate deep cycle batteries. Yeah, that would be cool. I've got a '79 Hunter 33.' Maybe I've got a mental block but I can't figure out where I could possibly put another battery bank. It's got little enough storage as it is. Seems I'd have to use the, um lockers under the, um port and starboard settees. Yuck. I wish I had more clearance above bilge pump in the bilge! The whole dang bilge is only about 18 inches deep or so. So that's why I've been asking about the cheaper, easier, but less powerful solution with the 2 group 27s I know I can fit. Forget about electric heat - it just isn't feasible with the batteries you have. Yeah, I've got a Force 10 propane. I'll get that working soon, hopefully. I just thought maybe I could use the floor electric heater in a backup situation if I needed to, on the 850watt setting if I need to. Looks like it won't be good for much else. The microwave, power tools (and possibly an electric kettle) are OK, as they are short-term loads, and the total ampere-hours used by them should be fairly low. The TV and boom box would be on for longer periods, but are fairly low draw, so may also be OK - but I would definitely want a separate starting battery! So in order to do without the seperate starting battery I can manage with careful planning, etc? Stephen |
On Sat, 26 Mar 2005 10:40:18 -0800, Stephen Trapani
wrote: So, say I've got a measley 2 group 27s and my old Yanmar 2GM15 and I want to by a 2300watt continuous inverter. BUT... ========================================== A pair of group 27s is totally inadequate for a high powered inverter, and as others have pointed out, your alternator is not big enough to make up the shortfall. My recommendation would be (4) 6 volt golf cart batteries in series parallel. They have about the same foot print as an 8D but are a couple of inches higher. The 4 golf carts will deliver 100 amps continuously for over 1/2 hour and intermittently for quite a bit longer. They can be purchased at Sam's club for about $50 each and are light enough to be easily handled. Don't skimp on the battery cables, nothing less than 2/0 will be big enough. |
Peter Bennett wrote:
On Sat, 26 Mar 2005 10:40:18 -0800, Stephen Trapani wrote: So, say I've got a measley 2 group 27s and my old Yanmar 2GM15 and I want to by a 2300watt continuous inverter. BUT... I'm willing to run the Yanmar while I'm using any heavy loads like a power tool, microwave, or electric heat and I only use the inverter *without* running the Yanmar/alternator for small loads like a TV/VCR or a boombox. Any problem with that? Stephen If I recall correctly, the stock (Hitachi?) alternator on my 2GM was only rated at 35 amps - that would only be enough to sustain a 3 amp (360 watt) load at 120 volts. (I replaced the stock alternator with a higher output unit, and a smart regulator, to give me some chance of keeping the batteries charged.) There are two alternators shipped with the small Yanmars - a 35 Amp and a 50 (or is it 55?) Amp Hitachi. I have the larger. On one engine I replaced it with a Balmar, but on those times that I've had to use the Hitachi for primary charging I've been disappointed in its output. I don't think it ever got to 35 Amps, and this was only when there was a heavy load. |
Stephen Trapani wrote:
Peter Bennett wrote: The microwave, power tools (and possibly an electric kettle) are OK, as they are short-term loads, and the total ampere-hours used by them should be fairly low. The TV and boom box would be on for longer periods, but are fairly low draw, so may also be OK - but I would definitely want a separate starting battery! So in order to do without the seperate starting battery I can manage with careful planning, etc? Only if you never go outside the range of SeaTow. If you have a number of electrical loads, its only a matter of time before you wake up and find the anchor light, plus the TV that you forgot to turn off, has drained the batteries. So the question becomes, do you need to start the engine to get back home? I would think that there is some place you could find to stash a small AGM starting battery that would greatly reduce this risk. BTW, one of my "pet peeves" is using an inverter to power a small TV, when there are plenty of TVs that run on DC more efficiently. You should read the specs carefully, because many TVs have significant loads, even when "turned off." For instance, my AC/DC 9 inch Panasonic draw almost 2 Amps more when powered on AC, and that load continues simply by being plugged in. This means that you could inadvertently draw an extra 25 Amp-hours overnight from this alone. There are other "forgotten" loads to think about. If you run the propane through a shutoff solenoid, that may draw a half Amp. And if you run it all night for a heater, you should have leak detector - another small but constant load. |
On Sat, 26 Mar 2005 20:48:42 -0800, Stephen Trapani
wrote: Peter Bennett wrote: Forget about electric heat - it just isn't feasible with the batteries you have. Yeah, I've got a Force 10 propane. I'll get that working soon, hopefully. I just thought maybe I could use the floor electric heater in a backup situation if I needed to, on the 850watt setting if I need to. Looks like it won't be good for much else. If I recall correctly, Group 27 deep cycle batteries are rated at 100 - 110 Ampere-hours, so you have about 200 AH capacity in total. It is generally recommended that deep cycle batteries should not be discharged more than half-way, so your usable capacity it only 100 AH. Your 850 watt heater will draw about 7 amps at 120 V, and the inverter will draw perhaps 75 - 80 amps (allowing for inverter inefficiencies). The AH rating of a battery is calculated assuming the battery will be fully discharged in 20 hours - for your 200 AH battery bank, this would mean a 10 amp discharge current. If you discharge the battery at greater than the 20 hour rate, the total energy you can extract is reduced. Your heater would require about 8 times the 20 hour rate. The table I have for this only goes up to 5, where the effective capacity is reduced to 72%. You could probably expect about 60% capacity, so you could only run the heater for about 40 minutes. (and then you might have trouble starting the engine.) The microwave, power tools (and possibly an electric kettle) are OK, as they are short-term loads, and the total ampere-hours used by them should be fairly low. The TV and boom box would be on for longer periods, but are fairly low draw, so may also be OK - but I would definitely want a separate starting battery! So in order to do without the seperate starting battery I can manage with careful planning, etc? Stephen Yes, maybe... You should look at the current required for each device you want to use, and how long you will use it, to determine the ampere-hours you will consume between recharges. A battery monitor like the Xantrex Link 20 can help you monitor the state of charge of your batteries. I still strongly recommend adding a separate starting battery - it is valuable insurance in the event you do discharge the house batteries too far. You should also replace the stock voltage regulator on the alternator with a "smart" or three-stage type - this will allow the engine to recharge the batteries much more effectively than it does now. A three-stage AC charger would also be a good investment (there may be one built into the inverter...) -- Peter Bennett, VE7CEI peterbb4 (at) interchange.ubc.ca new newsgroup users info : http://vancouver-webpages.com/nnq GPS and NMEA info: http://vancouver-webpages.com/peter Vancouver Power Squadron: http://vancouver.powersquadron.ca |
Comments inserted where appropriate below:
"Peter Bennett" wrote in message news.com... On Sat, 26 Mar 2005 20:48:42 -0800, Stephen Trapani wrote: Peter Bennett wrote: Forget about electric heat - it just isn't feasible with the batteries you have. Yeah, I've got a Force 10 propane. I'll get that working soon, hopefully. I just thought maybe I could use the floor electric heater in a backup situation if I needed to, on the 850watt setting if I need to. Looks like it won't be good for much else. If I recall correctly, Group 27 deep cycle batteries are rated at 100 - 110 Ampere-hours, so you have about 200 AH capacity in total. It is generally recommended that deep cycle batteries should not be discharged more than half-way, so your usable capacity it only 100 AH. Your 850 watt heater will draw about 7 amps at 120 V, and the inverter will draw perhaps 75 - 80 amps (allowing for inverter inefficiencies). The AH rating of a battery is calculated assuming the battery will be fully discharged in 20 hours - for your 200 AH battery bank, this would mean a 10 amp discharge current. If you discharge the battery at greater than the 20 hour rate, the total energy you can extract is reduced. Your heater would require about 8 times the 20 hour rate. The table I have for this only goes up to 5, where the effective capacity is reduced to 72%. You could probably expect about 60% capacity, so you could only run the heater for about 40 minutes. (and then you might have trouble starting the engine.) I'd go a little further on this estimate. Yes, you shouldn't go below 50% charge on your batteries which reduces your 200 AH battery bank to an effective 100 AH total as stated above, but you also will find it difficult to get your battery bank charged much above 85% by running the engine. An AC charger plugged into shore power running overnight is about the olny way you'll do it. It takes too long to trickle those last few amp hours in. So you've really only 70 AH total to work with in your two group 27's. I'd forget about the electric heater unless you can stay below 400 watts with the engine running. The rest of the things you suggested running off the inverter should be OK due to their intermittant use as explained by others. You asked a couple of questions in another post: "And then if I keep running the over-use after the batteries run down, the inverter overharge alarm will go on? No big deal I can just turn off the large draw and charge up the batteries before I turn off the Yanmar?" and: "One more question, is this sort of usage hard on the batteries at all? Wear them out faster or anything?" Running the inverter until the low battery voltage alarm comes on will take your batteries to a charge level far below 50% which will shorten their life quite dramatically, perhaps ruining them in just a few of these very deep cycles. The microwave, power tools (and possibly an electric kettle) are OK, as they are short-term loads, and the total ampere-hours used by them should be fairly low. The TV and boom box would be on for longer periods, but are fairly low draw, so may also be OK - but I would definitely want a separate starting battery! A separate starting battery wouldn't have to be very big, perhaps one the size used in a lawn tractor would do? It shouldn't be hard to find a place to put one that small. So in order to do without the seperate starting battery I can manage with careful planning, etc? Stephen Yes, maybe... You should look at the current required for each device you want to use, and how long you will use it, to determine the ampere-hours you will consume between recharges. A battery monitor like the Xantrex Link 20 can help you monitor the state of charge of your batteries. I still strongly recommend adding a separate starting battery - it is valuable insurance in the event you do discharge the house batteries too far. You should also replace the stock voltage regulator on the alternator with a "smart" or three-stage type - this will allow the engine to recharge the batteries much more effectively than it does now. A three-stage AC charger would also be a good investment (there may be one built into the inverter...) -- Peter Bennett, VE7CEI peterbb4 (at) interchange.ubc.ca new newsgroup users info : http://vancouver-webpages.com/nnq GPS and NMEA info: http://vancouver-webpages.com/peter Vancouver Power Squadron: http://vancouver.powersquadron.ca |
|
"Ken Heaton" wrote in
news:RZE1e.114238$fc4.16211@edtnps89: I'd forget about the electric heater unless you can stay below 400 watts Can I ask a silly question? Geez, don't tell any of the yacht professionals hanging around the dock if you do this, but why can't we simply install an ENGINE POWERED HEATER like the beast that turns my stepvan into an oven into the boat's cooling water loop, like the water heater??......Silly me. http://www.rustrepair.com/stepvan_pa...v&p=wi-heater- ht.aux The 6x7x6" 13,000 BTU small unit puts out TWICE as much heat as a 1500 watt AC heater many of you have now. Just mount it up under a table near the engine compartment to keep the hoses short and you're in business. Bigger boat? I have the 20,000 BTU unit in the back of my stepvan and at 30F it will run you out in 10 minutes! They have a 33,000 BTU model if you need it. They are very small....no bigger than your little electric heater you keep tripping over in the passageway. You'll need a heater control valve to control the water flow.... http://www.rustrepair.com/stepvan_pa...v&p=wi-heater- ht.val To be really nice, get one that uses a cable control.... 54-062 62" cable with knob that mounts through a simple hole. And a fan speed control.... http://www.rustrepair.com/stepvan_pa...sv&p=wi-heater switch and resistor.... These units are all made to run from the helm of the stepvan with the heater in the back so controls are separate. Sure beats the hell out of running the engine and inverter to power that crappy little heater in the passageway..... |
I know of a number of boat that have a similar setup. Webasto sells a whole
like of hot water based cabin heaters. So does Espar. I have seen several boats that have used regular automotive heater cores. No problem other than having to run the engine to get heat. Doug "Larry W4CSC" wrote in message ... "Ken Heaton" wrote in news:RZE1e.114238$fc4.16211@edtnps89: I'd forget about the electric heater unless you can stay below 400 watts Can I ask a silly question? Geez, don't tell any of the yacht professionals hanging around the dock if you do this, but why can't we simply install an ENGINE POWERED HEATER like the beast that turns my stepvan into an oven into the boat's cooling water loop, like the water heater??......Silly me. http://www.rustrepair.com/stepvan_pa...v&p=wi-heater- ht.aux The 6x7x6" 13,000 BTU small unit puts out TWICE as much heat as a 1500 watt AC heater many of you have now. Just mount it up under a table near the engine compartment to keep the hoses short and you're in business. Bigger boat? I have the 20,000 BTU unit in the back of my stepvan and at 30F it will run you out in 10 minutes! They have a 33,000 BTU model if you need it. They are very small....no bigger than your little electric heater you keep tripping over in the passageway. You'll need a heater control valve to control the water flow.... http://www.rustrepair.com/stepvan_pa...v&p=wi-heater- ht.val To be really nice, get one that uses a cable control.... 54-062 62" cable with knob that mounts through a simple hole. And a fan speed control.... http://www.rustrepair.com/stepvan_pa...sv&p=wi-heater switch and resistor.... These units are all made to run from the helm of the stepvan with the heater in the back so controls are separate. Sure beats the hell out of running the engine and inverter to power that crappy little heater in the passageway..... |
On Sun, 27 Mar 2005 19:49:53 -0500, Larry W4CSC
wrote: Can I ask a silly question? Geez, don't tell any of the yacht professionals hanging around the dock if you do this, but why can't we simply install an ENGINE POWERED HEATER like the beast that turns my stepvan into an oven into the boat's cooling water loop, like the water heater??......Silly me. That's a good suggestion in some situations - but the 2GM15 is a two cylinder 15 HP engine commonly used on sailboats around 30 ft, and is probably raw-water cooled, so your suggestion won't work. Even if the engine has a fresh water cooling system, an engine-powered heater like you suggest will only be useful while the engine is running - unless the OP wants to leave his engine running all evening while at anchor, it won't help. I think the best solution for his heating problem is a small Espar or Webasto diesel hot air furnace. He did mention that he has a Force 10 propane heater. The one I had one on a previous boat was a bulkhead-mounted "fireplace" with no provision to circulate the air. When I stood up in the boat, my head was cooking, but my feet were freezing.... That sort of heater needs a fan mounted above it to circulate the heated air. -- Peter Bennett, VE7CEI peterbb4 (at) interchange.ubc.ca new newsgroup users info : http://vancouver-webpages.com/nnq GPS and NMEA info: http://vancouver-webpages.com/peter Vancouver Power Squadron: http://vancouver.powersquadron.ca |
Just read the voltage coming out of the power supply dongle on the
LCD TV you're considering and look for anything from 12-15VDC output from it. The DC regulators are inside the TVs so it doesn't matter if it's off a few volts. Bad advice concerning the consumer grade LCD TVs I know of. The 120 volt AC to 12 volt wall wart *is* the voltage regulator, there is no DC regulator inside the TV. I called technical support concerning my Samsung SyncMaster 150mp and they said the voltage must be a clean 12.3 volts plus or minus 5%. Clean means no high voltage spikes or significant AC ripple. They said lots of folks are running this particular monitor in emergency vehiclesetc., but only by using a 10-16v--12v regulated power supply (expensive), *not* connecting directly to the vehicle's DC bus. Typical boat voltages range from 10v or so when running heavy loads like anchor windlasses, to 14.4v or so when charging. High voltages will burn out the cold cathode fluorescent backlight circuitry, every time. You either have an unusual LCD TV, never use the TV during the top end of a 3-step charging cycle, or are just plain lucky. |
"Mark" wrote in
ups.com: You either have an unusual LCD TV, never use the TV during the top end of a 3-step charging cycle, or are just plain lucky. I'll get the make/model next time I'm on the boat and post it. Functions flawlessly, here. |
Peter Bennett wrote in
news.com: I think the best solution for his heating problem is a small Espar or Webasto diesel hot air furnace. He did mention that he has a Force 10 propane heater. The one I had one on a previous boat was a bulkhead-mounted "fireplace" with no provision to circulate the air. When I stood up in the boat, my head was cooking, but my feet were freezing.... That sort of heater needs a fan mounted above it to circulate the heated air. This is the best idea, but there's no room on the small cruisers for it. Lionheart had a fuel oil forced air heater installed in the port lazarette when it was built. By the time Geoffrey got it, the heater was all rotten inside and he removed it to make room for the aft cabin heat pump, which is more important in Charleston. It looked like the salt air had simply consumed the diesel heater's steel combustion chamber. It was totally rusted out. |
In article .com,
Peter Bennett wrote: That's a good suggestion in some situations - but the 2GM15 is a two cylinder 15 HP engine commonly used on sailboats around 30 ft, and is probably raw-water cooled, so your suggestion won't work. Why would the fact that you have Raw water cooling be a deterent? All that is required is some High Temp Hose, and a Stainless Liquid/Air Heat Exchanger. Install the heat exchanger between the output of the engine block and the input to the Raw Water Exhaust Elbow Input. If you want heat just turn of the fan blowing thru the heat exchanger. If you don't want heat, just let the Raw water flow overboard after going thru the heat echanger. This isn't Rocket Scienc. Cogeneration of this type has been used on many a small vessel for many, many years, Fresh water or Raw water cooled. Look, you already PAID for those BTU's when you purchased your Dead Dinasour Guts. Better to use them, then heat up the ocean with them. Remeber 33% of your BTU's go out the output shaft, 33% go out the cooling system, and 33% go up the stack, in diesel engines. Bruce in alaska who would like to sell you some more dinasour guts... -- add a 2 before @ |
Must depend upon the rig. I've been running a 12V flatscreen Sharp
for 3 years with no problem. "Mark" wrote in message ups.com... Just read the voltage coming out of the power supply dongle on the LCD TV you're considering and look for anything from 12-15VDC output from it. The DC regulators are inside the TVs so it doesn't matter if it's off a few volts. Bad advice concerning the consumer grade LCD TVs I know of. The 120 volt AC to 12 volt wall wart *is* the voltage regulator, there is no DC regulator inside the TV. I called technical support concerning my Samsung SyncMaster 150mp and they said the voltage must be a clean 12.3 volts plus or minus 5%. Clean means no high voltage spikes or significant AC ripple. They said lots of folks are running this particular monitor in emergency vehiclesetc., but only by using a 10-16v--12v regulated power supply (expensive), *not* connecting directly to the vehicle's DC bus. Typical boat voltages range from 10v or so when running heavy loads like anchor windlasses, to 14.4v or so when charging. High voltages will burn out the cold cathode fluorescent backlight circuitry, every time. You either have an unusual LCD TV, never use the TV during the top end of a 3-step charging cycle, or are just plain lucky. |
My Espar is at least 10 years old is still runs great.
"Larry W4CSC" wrote in message ... Peter Bennett wrote in news.com: I think the best solution for his heating problem is a small Espar or Webasto diesel hot air furnace. He did mention that he has a Force 10 propane heater. The one I had one on a previous boat was a bulkhead-mounted "fireplace" with no provision to circulate the air. When I stood up in the boat, my head was cooking, but my feet were freezing.... That sort of heater needs a fan mounted above it to circulate the heated air. This is the best idea, but there's no room on the small cruisers for it. Lionheart had a fuel oil forced air heater installed in the port lazarette when it was built. By the time Geoffrey got it, the heater was all rotten inside and he removed it to make room for the aft cabin heat pump, which is more important in Charleston. It looked like the salt air had simply consumed the diesel heater's steel combustion chamber. It was totally rusted out. |
My experience is that the waste water from a raw water15HP Yanmar
doesn;t have enough residual heat to make running a heater practical. I know you can't run a water heater off of one. Doug "Bruce in Alaska" wrote in message ... In article .com, Peter Bennett wrote: That's a good suggestion in some situations - but the 2GM15 is a two cylinder 15 HP engine commonly used on sailboats around 30 ft, and is probably raw-water cooled, so your suggestion won't work. Why would the fact that you have Raw water cooling be a deterent? All that is required is some High Temp Hose, and a Stainless Liquid/Air Heat Exchanger. Install the heat exchanger between the output of the engine block and the input to the Raw Water Exhaust Elbow Input. If you want heat just turn of the fan blowing thru the heat exchanger. If you don't want heat, just let the Raw water flow overboard after going thru the heat echanger. This isn't Rocket Scienc. Cogeneration of this type has been used on many a small vessel for many, many years, Fresh water or Raw water cooled. Look, you already PAID for those BTU's when you purchased your Dead Dinasour Guts. Better to use them, then heat up the ocean with them. Remeber 33% of your BTU's go out the output shaft, 33% go out the cooling system, and 33% go up the stack, in diesel engines. Bruce in alaska who would like to sell you some more dinasour guts... -- add a 2 before @ |
IIRC, the thermostat on the raw water Yanmars is set rather low, about
140 degrees. This is too low for quickly heating hot water, and could be marginal for heating. In fact, when I run my fresh water 2GM20F for charging, it doesn't go above about 160 degrees, and takes a long time to heat my 11 gallon tank. When pushing the boat hard it brings the water up to temp in about 20 minutes. Doug Dotson wrote: My experience is that the waste water from a raw water15HP Yanmar doesn;t have enough residual heat to make running a heater practical. I know you can't run a water heater off of one. Doug "Bruce in Alaska" wrote in message ... In article .com, Peter Bennett wrote: That's a good suggestion in some situations - but the 2GM15 is a two cylinder 15 HP engine commonly used on sailboats around 30 ft, and is probably raw-water cooled, so your suggestion won't work. Why would the fact that you have Raw water cooling be a deterent? All that is required is some High Temp Hose, and a Stainless Liquid/Air Heat Exchanger. Install the heat exchanger between the output of the engine block and the input to the Raw Water Exhaust Elbow Input. If you want heat just turn of the fan blowing thru the heat exchanger. If you don't want heat, just let the Raw water flow overboard after going thru the heat echanger. This isn't Rocket Scienc. Cogeneration of this type has been used on many a small vessel for many, many years, Fresh water or Raw water cooled. Look, you already PAID for those BTU's when you purchased your Dead Dinasour Guts. Better to use them, then heat up the ocean with them. Remeber 33% of your BTU's go out the output shaft, 33% go out the cooling system, and 33% go up the stack, in diesel engines. Bruce in alaska who would like to sell you some more dinasour guts... -- add a 2 before @ |
Right, but raw water vs fresh water system is a different deal. Raw water:
no good for hot water or heat. Fresh water: usually OK. Doug "Jeff" wrote in message ... IIRC, the thermostat on the raw water Yanmars is set rather low, about 140 degrees. This is too low for quickly heating hot water, and could be marginal for heating. In fact, when I run my fresh water 2GM20F for charging, it doesn't go above about 160 degrees, and takes a long time to heat my 11 gallon tank. When pushing the boat hard it brings the water up to temp in about 20 minutes. Doug Dotson wrote: My experience is that the waste water from a raw water15HP Yanmar doesn;t have enough residual heat to make running a heater practical. I know you can't run a water heater off of one. Doug "Bruce in Alaska" wrote in message ... In article .com, Peter Bennett wrote: That's a good suggestion in some situations - but the 2GM15 is a two cylinder 15 HP engine commonly used on sailboats around 30 ft, and is probably raw-water cooled, so your suggestion won't work. Why would the fact that you have Raw water cooling be a deterent? All that is required is some High Temp Hose, and a Stainless Liquid/Air Heat Exchanger. Install the heat exchanger between the output of the engine block and the input to the Raw Water Exhaust Elbow Input. If you want heat just turn of the fan blowing thru the heat exchanger. If you don't want heat, just let the Raw water flow overboard after going thru the heat echanger. This isn't Rocket Scienc. Cogeneration of this type has been used on many a small vessel for many, many years, Fresh water or Raw water cooled. Look, you already PAID for those BTU's when you purchased your Dead Dinasour Guts. Better to use them, then heat up the ocean with them. Remeber 33% of your BTU's go out the output shaft, 33% go out the cooling system, and 33% go up the stack, in diesel engines. Bruce in alaska who would like to sell you some more dinasour guts... -- add a 2 before @ |
In article ,
"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote: My experience is that the waste water from a raw water15HP Yanmar doesn;t have enough residual heat to make running a heater practical. I know you can't run a water heater off of one. Doug Your dumping those "Paid for" BTU's overboard, and you would be very suprised at how much heat can be moved out of that Raw water cooling system that runs at 140F.... Bruce in alaska -- add a 2 before @ |
In article ,
"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote: Right, but raw water vs fresh water system is a different deal. Raw water: no good for hot water or heat. Fresh water: usually OK. Doug Geezzz Louise Doug, Think about this a bit. What is the difference between Raw Water Cooling, and Fresh Water Cooling? You got the same amount of BTU's coming out of the engine, right? Why would the addition of a Water/Water heat exchanger make any difference in how you distribute those BTU's? BTU's are BTU's. The heat has to go somewhere and if you pump it overboard your wasting the energy, that could be used to heat the cabin or water or anything else that requires input BTU's. Bruce in alaska -- add a 2 before @ |
"Bruce in Alaska" wrote in message ... In article , "Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote: My experience is that the waste water from a raw water15HP Yanmar doesn;t have enough residual heat to make running a heater practical. I know you can't run a water heater off of one. Doug Your dumping those "Paid for" BTU's overboard, and you would be very suprised at how much heat can be moved out of that Raw water cooling system that runs at 140F.... Bruce in alaska -- add a 2 before @ Never worked on my old boat. The 3HM30 raw water engine would never heat the water hot enough to be useful. After replacing it with a 3GM30F I had all the hot water I could use. Yanmar apparently told the previous owner (my father) that using a water heater with the 3HM30 would not work and that information was correct Doug |
| All times are GMT +1. The time now is 10:18 AM. |
Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 BoatBanter.com