I have an air x marine that I just installed and was told that it is ok to ground the unit to the bus bar on my 12 volt panel. Does this sound right (I am an extremely poor electrician)? Thanks, Robin
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Gord May
Further to Grounding Wind Gen'
GROUNDING vs GROUNDED: There are four main functions accomplished (on a boat) through GROUNDING: 1. Safety - prevent shock hazzard (AC green gnd wire) 2. Bonding - prevent corrosion (tie all immersed metals together) 3. Lightning & Static Amelioration - provide a preferred path to ground for lightning. 4. Counterpoise - provide an RF ground, or zero reference for electronics. None of these (4) GroundING wires are current-carrying, under NORMAL circumstances. All of these Safety or Bonding ground cables are connected directly to the Main Ground Bus. There are two main GROUNDED current-carrying conductors: 5. AC Neutral (White) 6. DC Negative Return (Yellow or Black) Both the AC Neutral and the DC (negative) Return are ultimately connected to ground (hence groundED) , but are NOT GroundING wires. The AC Neutral is connected to the (optional) Galvanic Isolator thence to the AC Neutral bus (at AC Panel), and finally the Main Ground Bus., The DC Negative Return is connected to the DC Negative Bus (at DC Panel), thence the Battery Negative Post, and finally to the Main Ground Bus. The Main Ground Bus may be the Engine Block, or (preferably) a dedicated grounding terminal (bus or block) which is connected to an external ground plate. To prevent confusion, it is preferred to refer to groundED (current-carrying) conductors (numbers 5 & 6) by the term(s): AC “Neutral”, or DC “Negative” (return), and to the groundING cables as “Safety” or “Bonding” ground. To your original question: “Can the Wind-Generator’s Green Ground wire be connected to the DC Panel’s Negative Terminal?” I would much prefer this “Safety Ground” be connected directly to the Main Ground Bus (or engine block). This green ground is intended to dissipate the static charge that builds up when the turbine blades spin, and to carry the huge currents of a lightning strike. The further from the DC loads this “static” ground is connected, the less likelihood of introducing “noise” into the DC wiring. Likewise, similar reasoning applies to lightning strikes (excepting the green wire is of too small a gauge to be really effective - see below). Because the energies (DC Current & EMF/RF Pulse) of a lightning strike are so high, I would like to see the Wind-Generator Tower additionally bonded, with a large 2/0 cable. See ABYC Section(s): E-8 Alternating Current (AC) Systems E-9 Direct Current (DC) Systems (Figures 15, 16 etc) E-4 Lightning Protection Hope the helps, Gord
GROUNDING vs GROUNDED: There are four main functions accomplished (on a boat) through GROUNDING: 1. Safety - prevent shock hazzard (AC green gnd wire) 2. Bonding - prevent corrosion (tie all immersed metals together) 3. Lightning & Static Amelioration - provide a preferred path to ground for lightning. 4. Counterpoise - provide an RF ground, or zero reference for electronics. None of these (4) GroundING wires are current-carrying, under NORMAL circumstances. All of these Safety or Bonding ground cables are connected directly to the Main Ground Bus. There are two main GROUNDED current-carrying conductors: 5. AC Neutral (White) 6. DC Negative Return (Yellow or Black) Both the AC Neutral and the DC (negative) Return are ultimately connected to ground (hence groundED) , but are NOT GroundING wires. The AC Neutral is connected to the (optional) Galvanic Isolator thence to the AC Neutral bus (at AC Panel), and finally the Main Ground Bus., The DC Negative Return is connected to the DC Negative Bus (at DC Panel), thence the Battery Negative Post, and finally to the Main Ground Bus. The Main Ground Bus may be the Engine Block, or (preferably) a dedicated grounding terminal (bus or block) which is connected to an external ground plate. To prevent confusion, it is preferred to refer to groundED (current-carrying) conductors (numbers 5 & 6) by the term(s): AC “Neutral”, or DC “Negative” (return), and to the groundING cables as “Safety” or “Bonding” ground. To your original question: “Can the Wind-Generator’s Green Ground wire be connected to the DC Panel’s Negative Terminal?” I would much prefer this “Safety Ground” be connected directly to the Main Ground Bus (or engine block). This green ground is intended to dissipate the static charge that builds up when the turbine blades spin, and to carry the huge currents of a lightning strike. The further from the DC loads this “static” ground is connected, the less likelihood of introducing “noise” into the DC wiring. Likewise, similar reasoning applies to lightning strikes (excepting the green wire is of too small a gauge to be really effective - see below). Because the energies (DC Current & EMF/RF Pulse) of a lightning strike are so high, I would like to see the Wind-Generator Tower additionally bonded, with a large 2/0 cable. See ABYC Section(s): E-8 Alternating Current (AC) Systems E-9 Direct Current (DC) Systems (Figures 15, 16 etc) E-4 Lightning Protection Hope the helps, Gord
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Robin
Thanks!
Gord, Thanks for the great info. Now I just have to figure out what the main bus is on my boat, a 1985 Hunter 34. The green (grounding) wire is presently connected to what I believe is the grounding bus bar on the fuse panel. I did not think this was the negative wire terminal, but I may be wrong. Since the lightning grounding wires (from the mast and shrouds)are connected to the keel (iron), I was thinking that the keel was the main bus. What if I connect the grounding wire to the back stay which via grounding wire from the shroud chainplates are connected to the keel. Does this sound like it would be a problem? I am nervous about connecting stuff to the engine since I have heard about serious galvanic corrosion occuring on the shaft and prop when grounding wires were connected to the engine. Thanks!
Gord, Thanks for the great info. Now I just have to figure out what the main bus is on my boat, a 1985 Hunter 34. The green (grounding) wire is presently connected to what I believe is the grounding bus bar on the fuse panel. I did not think this was the negative wire terminal, but I may be wrong. Since the lightning grounding wires (from the mast and shrouds)are connected to the keel (iron), I was thinking that the keel was the main bus. What if I connect the grounding wire to the back stay which via grounding wire from the shroud chainplates are connected to the keel. Does this sound like it would be a problem? I am nervous about connecting stuff to the engine since I have heard about serious galvanic corrosion occuring on the shaft and prop when grounding wires were connected to the engine. Thanks!
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Gord May
Groundin/Bonding & Corrosion
I presume you are referring to the Wind-Gen' Green grounding wire, as being connected to the Negative terminal on the DC fuse panel. As stated, I prefer not to do it this way. If your stays and chainplates are effectively grounded (large cable not small wire) to an external (not encapsulated) steel keel, then you CAN safety ground the Wind-Gen' to the grounded back-stay. Your engine IS grounded. Your DC Panel is connected to the engine, at least through the Battery Negative & Starter connection. The whole issue of corrosion is poorly treated in the literature - having read much on the subject, I've yet to find an analysis I can fully agree with. The hazards of bonding are NOT NEARLY as prevelant as many would have you believe. OMO: The bottom line is that safety (complete bonding & grounding) trumps convenience (anti-corrosion) EVERY TIME. Regards, Gord
I presume you are referring to the Wind-Gen' Green grounding wire, as being connected to the Negative terminal on the DC fuse panel. As stated, I prefer not to do it this way. If your stays and chainplates are effectively grounded (large cable not small wire) to an external (not encapsulated) steel keel, then you CAN safety ground the Wind-Gen' to the grounded back-stay. Your engine IS grounded. Your DC Panel is connected to the engine, at least through the Battery Negative & Starter connection. The whole issue of corrosion is poorly treated in the literature - having read much on the subject, I've yet to find an analysis I can fully agree with. The hazards of bonding are NOT NEARLY as prevelant as many would have you believe. OMO: The bottom line is that safety (complete bonding & grounding) trumps convenience (anti-corrosion) EVERY TIME. Regards, Gord
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James
Wind Generator
As I sit in Irons on the Mississippi, I cant help but wish for a Wind Generator.... ;-) J "Hey you on shore, drop a quarter in the wind machine!"
As I sit in Irons on the Mississippi, I cant help but wish for a Wind Generator.... ;-) J "Hey you on shore, drop a quarter in the wind machine!"
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Tim Donley
Galvanic Isolator Re:Gord May
Please review your reply re: the galvanic isolator. The galvanic isolator is always on the GREEN grounding conductor of the A.C. system between the grounding buss and the shore inlet (ABYC E-8.20)only. This isolates you from your neighborhood and all the faults the surrounding boats may have. To advise otherwise is DANGEROUS! By doing so there is a chance of disabling the reverse polarity indicator lite. I won't be swimming around your boat. The white GROUNDED nuetral wire is wired through the A.C. shore inlet breaker(DPDT) as well as the black UNGROUNDED wire (hot).This totaly dissconnects the boat from dock side connections when in the OFF position. Please understand I have been in the boat building business for over 30 years, not reading about it. There is a lot I don't know, but I am still learning every day, as we all are. Bye the way , anybody see "Pirates Of The Carribean"? Good flick,see it at the theater don't wait for dvd, you will buy it on dvd anyway. Stay to the very end of the credits..........savy? Tim
Please review your reply re: the galvanic isolator. The galvanic isolator is always on the GREEN grounding conductor of the A.C. system between the grounding buss and the shore inlet (ABYC E-8.20)only. This isolates you from your neighborhood and all the faults the surrounding boats may have. To advise otherwise is DANGEROUS! By doing so there is a chance of disabling the reverse polarity indicator lite. I won't be swimming around your boat. The white GROUNDED nuetral wire is wired through the A.C. shore inlet breaker(DPDT) as well as the black UNGROUNDED wire (hot).This totaly dissconnects the boat from dock side connections when in the OFF position. Please understand I have been in the boat building business for over 30 years, not reading about it. There is a lot I don't know, but I am still learning every day, as we all are. Bye the way , anybody see "Pirates Of The Carribean"? Good flick,see it at the theater don't wait for dvd, you will buy it on dvd anyway. Stay to the very end of the credits..........savy? Tim
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Derek Rowell
What do you mean by grounding?
If you mean connecting the negative dc connection of the wind generator, then you should do it at (a) the main "grounding" point on the engine (where the battery cable is grounded, (2) at the battery negative connections, or (3) on the ground bus in the dc panel at the nav station. If you are talking about grounding the housing/mast for lightning ptotection, I would use the engine ground, or somehow attach to the keel bolts. Use a heavy gauge wire (at least 6 AWG) and make a solid connection at both ends. (The ground connection on my old H34 was simply a 10 or 12 AWG wire squeezed under a washer on a keel bolt. Ridiculous.) All of this talk about galvanic isolators has nothing to do with your boats dc system - the only function of these is protection against stray currents from the ac shore supply. Your ac and dc ground connections should be made at one point only!!!
If you mean connecting the negative dc connection of the wind generator, then you should do it at (a) the main "grounding" point on the engine (where the battery cable is grounded, (2) at the battery negative connections, or (3) on the ground bus in the dc panel at the nav station. If you are talking about grounding the housing/mast for lightning ptotection, I would use the engine ground, or somehow attach to the keel bolts. Use a heavy gauge wire (at least 6 AWG) and make a solid connection at both ends. (The ground connection on my old H34 was simply a 10 or 12 AWG wire squeezed under a washer on a keel bolt. Ridiculous.) All of this talk about galvanic isolators has nothing to do with your boats dc system - the only function of these is protection against stray currents from the ac shore supply. Your ac and dc ground connections should be made at one point only!!!
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Gord May
IMPORTANT CORRECTION !!!
Oops, I goofed - Derek is absolutely correct. The White AC Neutral is connected to the D.P. Main Breaker - NOT to the Galvanic Isolator. The Green AC Ground IS Connected to the Optional Galvanic Isolator, thence to the DC Negative Bus. Sorry, I don't know how to correct or delete. my original post. I look forward to future postings from Derek Rowell - he's obviously not only knowledgable, but also a good reader.
Oops, I goofed - Derek is absolutely correct. The White AC Neutral is connected to the D.P. Main Breaker - NOT to the Galvanic Isolator. The Green AC Ground IS Connected to the Optional Galvanic Isolator, thence to the DC Negative Bus. Sorry, I don't know how to correct or delete. my original post. I look forward to future postings from Derek Rowell - he's obviously not only knowledgable, but also a good reader.
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Gord May
IMPORTANT CORRECTION !!!
Oops, I goofed - Tim is absolutely correct. The White AC Neutral is connected to the D.P. Main Breaker - NOT to the Galvanic Isolator. The Green AC Ground IS Connected to the Optional Galvanic Isolator, thence to the DC Negative Bus. Sorry, I don't know how to correct or delete. my original post. I look forward to future postings from Tim Donley - he's obviously not only knowledgable, but also a good reader.
Oops, I goofed - Tim is absolutely correct. The White AC Neutral is connected to the D.P. Main Breaker - NOT to the Galvanic Isolator. The Green AC Ground IS Connected to the Optional Galvanic Isolator, thence to the DC Negative Bus. Sorry, I don't know how to correct or delete. my original post. I look forward to future postings from Tim Donley - he's obviously not only knowledgable, but also a good reader.
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Tim Donley
Thank you Gord May
Thanks for responding to my comments Gord, I'm glad you understood the reply. While it has nothing to do with a wind generator (Derek) ,it was important to bring the correction to light for any readers that aren't up to speed on these issues.A lot of readers take most of what is said on these sites to heart as fact,we must be responsible to advise otherwise when possible and hope not to offend in the process. Regarding lightning protection there is a web site selling equipment for this purpose, a visit to the site is VERY INFORMATIVE on the issue of understanding lightning protection www.strikeshield.com
Thanks for responding to my comments Gord, I'm glad you understood the reply. While it has nothing to do with a wind generator (Derek) ,it was important to bring the correction to light for any readers that aren't up to speed on these issues.A lot of readers take most of what is said on these sites to heart as fact,we must be responsible to advise otherwise when possible and hope not to offend in the process. Regarding lightning protection there is a web site selling equipment for this purpose, a visit to the site is VERY INFORMATIVE on the issue of understanding lightning protection www.strikeshield.com
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