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**GordMay** · 27-06-2008, 05:59

Quote:

Originally Posted by ess105

Gord - thanks for pointing out the risks. At the end of the day we must choose to either avoid, manage, assume or ignore risks. If we always avoid them we'll never get out of bed in the morning. 80V DC is a risk that I believe can be managed well if one is aware of the risks...

My intent was more to differentiate between the mechanisms* of AC and DC shock hazard, with reference to Alan’s comment, than it was to be cautionary.

* AC is actually MORE likely to grab you than DC, except ...

**Alan Wheeler** · 28-06-2008, 01:00

Great reading Gord.
ess105, yes any voltage can be catered fro. Any voltage has an issue. Whether it be something that can hurt, kill or just waste away your anodes. So apart from ensuring you use the correct grade of wiring, you can indeed cater for voltage you are using. Ensure your wiring is well coded to ensure that the voltage present is easily identified. You may find that any connectors and terminations could have to be specialised. At some point voltage AC and DC goes from what is considered Low voltage to High Voltage which require different codes of practice. Gord should be able to find relevant requirements for your part of the world ;-)

**GordMay** · 28-06-2008, 02:22

Quote:

Originally Posted by Alan Wheeler

... At some point voltage AC and DC goes from what is considered Low voltage to High Voltage which require different codes of practice...

We are very un-likely to encounter “High Voltage”, on our boats.
Usually, our Alternating Current circuits will be “Low Voltage” (LV), and our Direct Current circuits “Extra Low Voltage” (ELV).

Typically, “High Voltage” refers to voltages over about* 1000 Volts AC, or 1500 Volts DC.
“Low Voltage” refers to Voltages above “Extra Low Voltage”* and below High Voltage.

* “Extra Low Voltage” (ELV) is not consistently nor uniformly defined, though 50 Volts DC is one commonly accepted maximum.

In North America, “ELV” has been defined* as “not greater than 30 volts AC rms and 60 volts DC” (110.26), “less than 50 Volts (720), and “0 through 150 Volts AC & DC”(725). Article 725, that contains most of the rules for low voltage and low power remote control, signaling and power limited circuits divides these circuits into Class 1, Class 2, and Class 3 circuits.

* National Electrical Code (NFPA 70 & Canadian Electrical Code (CSAC21.1)

in Australia & New Zealand, “ELV” is defined as “not exceeding 50 V AC, or 120V ripple free DC; and Low-Voltage as “is at or below
1000 Volts AC or 1500 Volts DC”.

Boat Cable (UL 1426) is rated to at least 600 Volts maximum; whereas SAE (Automotive) cable is usually rated to 50 Volts maximum.

Intentional Drifter · 28-06-2008, 04:19

Schoonerdog, I'm curious where you mounted the panels. Do you have any pics you can post? I'm looking at increasing the panels on my St. F.

Thanks.

ID

db8us · 28-06-2008, 10:34

Quote:

Originally Posted by SettingSail2009

I'm in the process of mounting two 215 watt Sanyo panels with a Blue Sky solar booster in addition to the Air Breeze unit. I'm really curious how many amps I'll be able to wring out of them. I think it'll be a good set-up, both for sunny and windy days, because they usually don't coincide.

Hi Andreas,

i have one of those Sanyos and i see around 12A max, but it is mounted horizontally and not adjustable.

Regards

Michael

Stella Polaris · 28-06-2008, 15:14

Quote:

Originally Posted by db8us

I have one of those Sanyos and i see around 12A max, but it is mounted horizontally and not adjustable.

Hi Michael,

I'll have the same set-up (though with two panels) ... hopefully the booster will give me a little extra. If not 12A per panel is not that bad either. I'll be in Norway the next year and something tells me I'll be getting most of my juice from the wind generator. When I head down south I think it'll be a different story.

Fishspearit · 29-06-2008, 05:47

Maybe some of you guys with battery monitors could post how many amp-hours a day your solar panels are putting out. I'm looking at a flat installation that I won't be able to adjust, and wondering what the thumbrule is. 1/3 of the wattage in amp-hours? I know it varies by location and time of year.

Whimsical · 29-06-2008, 07:55

Quote:

Originally Posted by Fishspearit

Maybe some of you guys with battery monitors could post how many amp-hours a day your solar panels are putting out. I'm looking at a flat installation that I won't be able to adjust, and wondering what the thumbrule is. 1/3 of the wattage in amp-hours? I know it varies by location and time of year.

I think there will be a lot of distortion in those numbers due to the sizes of battery banks and the amount of discharge. You may have the potential to deliver 500ah to the batts but if they are full they wont take it.

Mike

ssullivan · 29-06-2008, 09:41

12-15 amps today, on a mostly sunny day from a pair of BP Solar 125 watt panels, fixed mounted.

camaraderie · 29-06-2008, 18:07

Assuming bulk charging rate acceptance...you may expect around 1/4 to 1/3 of the wattage rating to be delivered as amp hours to your battery on fixed mount panels (which may be angled to maximize angle of incidence) over time. You'll get closer to 1/3 based on latitude and minimal cloud cover and use of an mppt controller. Not saying you can't get more output...just saying that over time...this is a good estimate of what you will get on a daily basis...i.e. 100watts of panels will give 25-33 amp/hours back.

**Alan Wheeler** · 29-06-2008, 23:10

I have a good fiend that works for a tele-comunications company here in NZ. A cell site went out on them in the weekend and he was called out to take a look. It was a remtoe site out in the sounds with Boat access only. He arrived to find 3000W of solar panels completely gone. Whoever stole them was nice enough to disconnect the wiring using the right tools.

schoonerdog · 30-06-2008, 08:46

I.D., I placed two solar panels up on the arch aft, replacing the stock 75s. They stick out further aft than the originals but they fit very well in that space. The other two I put on the furthest starboard and port side of the bimini. I did have a new bimini frame made though which has a slight curve, the folding flat frame I thought was a little unstable for a new cover and had no curve so had a harder time shedding water. I'll see if my wife has some pictures we can post.

schoonerdog · 30-06-2008, 08:52

I find that exactly right. I lived completely off solar panels in the bahamas for a year with our old catamaran and logged amps being charged hourly in different conditions throughout the day. After several days of these logs I found that I got about 1/3 the power in amp hours, so my 325 watts of power provided around 110 amp hours per day. BTW, having completely solar charging does allow you to actually REDUCE your battery size because you are now not compensating for 24 hour charge cycles that typically one would do for generator or alternator based charging, but only night time draw. I think once I increase the ventilation of the freezer and refrigerator compressors I can get down to around 70 amps of nightly draw in tropic conditions.

Quote:

Originally Posted by camaraderie

Assuming bulk charging rate acceptance...you may expect around 1/4 to 1/3 of the wattage rating to be delivered as amp hours to your battery on fixed mount panels (which may be angled to maximize angle of incidence) over time. You'll get closer to 1/3 based on latitude and minimal cloud cover and use of an mppt controller. Not saying you can't get more output...just saying that over time...this is a good estimate of what you will get on a daily basis...i.e. 100watts of panels will give 25-33 amp/hours back.

Intentional Drifter · 01-07-2008, 05:58

Thanks, Schoonerdog. We're hoping to put much less time on the genset next year. Part of me is also hoping that Nanosolar won't be another unfulfilled promise. I'd love to have both cheaper and flexible solar panels available. With how they describe their new panels, it seems like it would be possible to cover the bimini with them.

ID