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what size wire to use for 30amp 12v circuit ?
Is there an online chart of wire sizing for 220v, 110v and 12v wiring ?
Thank you, Courtney |
what size wire to use for 30amp 12v circuit ?
Courtney,
http://www.ancorproducts.com/ look under technical information Be aware that even these people are stuck in % voltage drop when at 12v you very often have to be concerned more with actual value and not percentage of supply. Matt Colie Courtney Thomas wrote: Is there an online chart of wire sizing for 220v, 110v and 12v wiring ? Thank you, Courtney |
what size wire to use for 30amp 12v circuit ?
The Ancor calculator Matt mentioned is about right. Things to keep in mind
are that a 25 foot length of wire is only good for 12.5 feet of distance..........out and back, right? And the type insulation is worth considering, particularly if it's going to be near any heat, oil, sunlight, etc, etc. Remember also that under emergency conditions (no alternator turning) there isn't going to be that comfortable 14.7 volts to fall back on, but something like 12.3 or 12.4 from a good, recently charged battery. Lots of high class SSB radios will start jumping frequency or channels with 11 volts at the radio, and the tuner will also be trying to retune everytime you holler "Heeeelp" in the mic. Welding cable is worth considering. Fine, cable laid wire with good tough neoprene jacketing. Terminals deserve good swedged tools, and wicking a little solder in after the swedging is super around salt water and batteries. Old Chief Lynn |
what size wire to use for 30amp 12v circuit ?
In article ,
"Lynn Coffelt" wrote: The Ancor calculator Matt mentioned is about right. Things to keep in mind are that a 25 foot length of wire is only good for 12.5 feet of distance..........out and back, right? And the type insulation is worth considering, particularly if it's going to be near any heat, oil, sunlight, etc, etc. Remember also that under emergency conditions (no alternator turning) there isn't going to be that comfortable 14.7 volts to fall back on, but something like 12.3 or 12.4 from a good, recently charged battery. Lots of high class SSB radios will start jumping frequency or channels with 11 volts at the radio, and the tuner will also be trying to retune everytime you holler "Heeeelp" in the mic. Welding cable is worth considering. Fine, cable laid wire with good tough neoprene jacketing. Terminals deserve good swedged tools, and wicking a little solder in after the swedging is super around salt water and batteries. Old Chief Lynn I agree with "Old Chief Lynn" here, if the appliance we're discussing here is an MF/HF SSB Radio. The thing that needs to be understood is that Battery Voltage at the terminals is NOT Voltage at the back of the Radio, or at the PowerAmp DC Terminals, especially at the 20 to 25 Amp draw of a 100 to 150 watt Peak Envelope Power Radio. It is commonly understood that for each volt dropped from 13.6 VDC at the radios PowerAmp DC Terminals, you lose 50% of your PEP Power. So if your at 13.6 Vdc you get your 150 PEP, and at 12.6 VDC you get 75 PEP, and at 11.6 Vdc you get 35 PEP and below 11.0 VDC the internal Voltage Regulators drop out of regulation and the radio goes OFF. So any voltage drop associated with the wiring between the battery and the radio at the the Demand Input Current of the radio, effects the available output power. How many times have I seen a radio that receives perfectly, but dies whenever you press the PTT and modulate the Mic. LOTS. This is one of the reasons that the Powersupplys for FVSA (Fishing Vessel Safety ACT) and SOLAS requires that any batteries used for powering these MF/HF SSB Radios be on or above the same deck as the Radio, and Battery Condition be certified each year by a Discharge Test, in the case of SOLAS Required Vessels. When FVSA was out for Public Comment, there was a bit of a uproar about this requirment, as no one had that type of power system aboard, but it was made LAW anyway, and most of the fleet installed the required battery under the wheelhouse floor, right behind the wheelhouse on that deck, or on top of the wheelhouse. These locations will tend to keep the wire runs short, and any installer woirth his Salt, should and would DOUBLE the wiresize on the MF/HF SSB Radio that any table stated would be good enough. Most of the vessels I Inspected had AC PowerSupplies, or DC/DC Converters running from Ships Power of 120Vac or 32Vdc and Power leads of a foot or two, before the FVSA, and we just added an 8D battery between the two. Bruce in alaska -- add a 2 before @ |
what size wire to use for 30amp 12v circuit ?
Where did you hear that myth??? Iv'e been a marine electronics tech for 30
years and have never heard that one. I know what you stated is total bs but just for drill I did a little test before leaving work today. Hooked up a variable power supply to my Icom 735 with a Bird 4381 power analyst in line (which reads PEP directly). I also verified the wattmeter readings using an o-scope. The power didn't start to drop til the voltage dropped below 10.5v and I was able to receive just fine all the way down to 9.5v. Below that the rig started to die. Eric "Bruce in Alaska" wrote in message ... It is commonly understood that for each volt dropped from 13.6 VDC at the radios PowerAmp DC Terminals, you lose 50% of your PEP Power. So if your at 13.6 Vdc you get your 150 PEP, and at 12.6 VDC you get 75 PEP, and at 11.6 Vdc you get 35 PEP and below 11.0 VDC the internal Voltage Regulators drop out of regulation and the radio goes OFF. |
what size wire to use for 30amp 12v circuit ?
|
what size wire to use for 30amp 12v circuit ?
In article ,
"Eric Fairbank" wrote: Where did you hear that myth??? Iv'e been a marine electronics tech for 30 years and have never heard that one. I know what you stated is total bs but just for drill I did a little test before leaving work today. Hooked up a variable power supply to my Icom 735 with a Bird 4381 power analyst in line (which reads PEP directly). I also verified the wattmeter readings using an o-scope. The power didn't start to drop til the voltage dropped below 10.5v and I was able to receive just fine all the way down to 9.5v. Below that the rig started to die. Eric "Bruce in Alaska" wrote in message ... It is commonly understood that for each volt dropped from 13.6 VDC at the radios PowerAmp DC Terminals, you lose 50% of your PEP Power. So if your at 13.6 Vdc you get your 150 PEP, and at 12.6 VDC you get 75 PEP, and at 11.6 Vdc you get 35 PEP and below 11.0 VDC the internal Voltage Regulators drop out of regulation and the radio goes OFF. It is not a Myth, is is a Fact, and as others have stated, your experiment doesn't prove, or disprove the fact. Also, as Larry stated the 21st Century Icom Rigs have a lot more headroom in the SolidState Amps than just about any other Marine MF/HF Radio, just to deal with this cause. Just try your experiment with ANY SGC designed and built radio. Bruce in alaska I am Old School, and an Old Fart, and I do remember back in the Old Days, before Autotuners, allowed anyone to think they were World Class Radiomen... -- add a 2 before @ |
what size wire to use for 30amp 12v circuit ?
"Bruce in Alaska" wrote in message
... It is not a Myth, is is a Fact, and as others have stated, your experiment doesn't prove, or disprove the fact. Also, as Larry stated the 21st Century Icom Rigs have a lot more headroom in the SolidState Amps than just about any other Marine MF/HF Radio, just to deal with this cause. But.... it is also a fact that any modern rig that is also allowed on commercial vessels (IEC/EN60945) will never show this behavior, otherwise they wouldn't be able to pass the the tests to comply with that standard. Meindert |
what size wire to use for 30amp 12v circuit ?
"Eric Fairbank" wrote:
Where did you hear that myth??? Iv'e been a marine electronics tech for 30 years and have never heard that one. I know what you stated is total bs but just for drill I did a little test before leaving work today. Hooked up a variable power supply to my Icom 735 with a Bird 4381 power analyst in line (which reads PEP directly). I also verified the wattmeter readings using an o-scope. The power didn't start to drop til the voltage dropped below 10.5v and I was able to receive just fine all the way down to 9.5v. Below that the rig started to die. Eric "Bruce in Alaska" wrote in message ... It is commonly understood that for each volt dropped from 13.6 VDC at the radios PowerAmp DC Terminals, you lose 50% of your PEP Power. So if your at 13.6 Vdc you get your 150 PEP, and at 12.6 VDC you get 75 PEP, and at 11.6 Vdc you get 35 PEP and below 11.0 VDC the internal Voltage Regulators drop out of regulation and the radio goes OFF. It is not a Myth, is is a Fact, and as others have stated, your experiment doesn't prove, or disprove the fact. Also, as Larry stated the 21st Century Icom Rigs have a lot more headroom in the SolidState Amps than just about any other Marine MF/HF Radio, just to deal with this cause. Just try your experiment with ANY SGC designed and built radio. Bruce in alaska I am Old School, and an Old Fart, and I do remember back in the Old Days, before Autotuners, allowed anyone to think they were World Class Radiomen... -- Oh, my gosh, it's just killing me to sit here without jumping in! Then when I heard SGC mentioned, I knew that someone besides me had experienced "Bruce's Law". I am compelled to defend his position and scientific observations without reservation. How much midnight oil I've spent working on the DC supply system on "commercial" vessels, trying to reduce the voltage drop. Until the "code" made batterys in the pilot house almost mandatory, can't you imagine running an SGC711 from engine room batterys? Here's a typical example (it is a genuine "commercial", by the way) of a vessel still using this one time popular rig: http://www.alaskaboat.com/sn033.htm Those SGC711's were hard to coax to even 75 watts PEP with any wire less than #4 if you were more than two feet away from the battery! (OK, stretching a little here) And the built-in wire antenna tuner was a charmer, hey? But as the URL and dozens more can show, that not everyone has yet to install an Icom M802. Some earlier SEA's and Icom's with first generation digital VCO tuning were cool, too. A sneeze or laugh in the mic was as apt to change channels as anything if the antenna was fed directly from the radio, and some joker installed #10 wire for DC power! Early automatic antenna tuners were (are) cool, too. A little pitching and rolling in the North Pacific and they would lock up and refuse to even try to tune anymore. Then the transmitter's fabulous SWR power foldback circuit hit the fan and 5 to 10 watts could be used to heat up the tuner's coils and capacitors. (condensers, actually) Lots of this early stuff is still out there. By the thousands. Modern marine SSB radios certainly have improved their ability to survive poor installations, but is that any reason to go as cheap as possible with DC wiring and antenna installations? (RF ground on "Tupperware" boats is probably just as important, but I digress) Old Chief Lynn (besides, tubes help heat the pilothouse and ease aching joints) |
what size wire to use for 30amp 12v circuit ?
Lynn Coffelt wrote: "Eric Fairbank" wrote: Where did you hear that myth??? Iv'e been a marine electronics tech for 30 years and have never heard that one. I know what you stated is total bs but just for drill I did a little test before leaving work today. Hooked up a variable power supply to my Icom 735 with a Bird 4381 power analyst in line (which reads PEP directly). I also verified the wattmeter readings using an o-scope. The power didn't start to drop til the voltage dropped below 10.5v and I was able to receive just fine all the way down to 9.5v. Below that the rig started to die. Eric "Bruce in Alaska" wrote in message ... It is commonly understood that for each volt dropped from 13.6 VDC at the radios PowerAmp DC Terminals, you lose 50% of your PEP Power. So if your at 13.6 Vdc you get your 150 PEP, and at 12.6 VDC you get 75 PEP, and at 11.6 Vdc you get 35 PEP and below 11.0 VDC the internal Voltage Regulators drop out of regulation and the radio goes OFF. It is not a Myth, is is a Fact, and as others have stated, your experiment doesn't prove, or disprove the fact. Also, as Larry stated the 21st Century Icom Rigs have a lot more headroom in the SolidState Amps than just about any other Marine MF/HF Radio, just to deal with this cause. Just try your experiment with ANY SGC designed and built radio. Bruce in alaska I am Old School, and an Old Fart, and I do remember back in the Old Days, before Autotuners, allowed anyone to think they were World Class Radiomen... -- Oh, my gosh, it's just killing me to sit here without jumping in! Then when I heard SGC mentioned, I knew that someone besides me had experienced "Bruce's Law". I am compelled to defend his position and scientific observations without reservation. How much midnight oil I've spent working on the DC supply system on "commercial" vessels, trying to reduce the voltage drop. Until the "code" made batterys in the pilot house almost mandatory, can't you imagine running an SGC711 from engine room batterys? Here's a typical example (it is a genuine "commercial", by the way) of a vessel still using this one time popular rig: http://www.alaskaboat.com/sn033.htm Those SGC711's were hard to coax to even 75 watts PEP with any wire less than #4 if you were more than two feet away from the battery! (OK, stretching a little here) And the built-in wire antenna tuner was a charmer, hey? But as the URL and dozens more can show, that not everyone has yet to install an Icom M802. Some earlier SEA's and Icom's with first generation digital VCO tuning were cool, too. A sneeze or laugh in the mic was as apt to change channels as anything if the antenna was fed directly from the radio, and some joker installed #10 wire for DC power! Early automatic antenna tuners were (are) cool, too. A little pitching and rolling in the North Pacific and they would lock up and refuse to even try to tune anymore. Then the transmitter's fabulous SWR power foldback circuit hit the fan and 5 to 10 watts could be used to heat up the tuner's coils and capacitors. (condensers, actually) Lots of this early stuff is still out there. By the thousands. Modern marine SSB radios certainly have improved their ability to survive poor installations, but is that any reason to go as cheap as possible with DC wiring and antenna installations? (RF ground on "Tupperware" boats is probably just as important, but I digress) Old Chief Lynn (besides, tubes help heat the pilothouse and ease aching joints) Let's just watch out here. I was in a junk shop a while ago and I told the proprietor what was actually hoping to find. We got talking about ships and boats. He stopped and asked if I could tell him about something in back. When retrieved, it turned out to be a marine HF - real live dinosaur (dynosoar?). I think is was Hammerlund or EF Johnson - most of the crystals had been pulled, but it still had a the 2 1625s in the final (and a little burned spot on the tank). I looked at him and said "You know - They haven't made 'em like this for a long time". (Aren't we glad!) Matt Colie - Lifelong Waterman, Licensed Mariner and Perpetual Sailor |
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