Re: [AMRadio] #4 wire from mains? - they gotta be kidding
From: "Bill Smith" <[EMAIL PROTECTED]> Don't be afraid to use large wire in primary feeds. I have seen the result of "skimping" with the result conduit noticeably warms after about 10 - 15 minutes of operation. The worst consequence is a power sag when the transmitter comes on with the result that in the extreme, contactors won't operate correctly. The wire tables specify the minimum wire size, especially if long runs are contemplated (fifty feet or so). You will never regret using the next size, even if it is initially more expensive. The current price of copper does not make the decision any easier. Don't forget to use oxygen-free copper wire conductors, and hospital grade mains outlets. Expect good oxygen-free copper a.c. wiring at that power level to cost you upwards of $500 a foot, but after you have tried it, you will find that it's well worth it. You won't notice much, if any difference from ordinary copper wire the first time you fire up the transmitter. The wire must be "broken in" first. But once it is well broken in after a total of maybe 100 hours of operation, the improvement in signal reports you get with that transmitter will be astounding. Don k4kyv __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] #4 wire from mains? - they gotta be kidding
On 5/9/07, A.R.S. - W5AMI <[EMAIL PROTECTED]> wrote: I've been reading the Gates BC-1T manual and found two instances where they state that #4 wire should be used. One says: "3) ...provide #4 or larger primary wiring from entrance box to transmitter". A lot of good info from the folks here, Brian. They've covered it all from line regulation, insulation, length of run, 24/7 operation, etc. Larger wire, even if not technically needed in all situations, certainly covers it all in one fell swoop. I picked up some nice cable recently for transmitter power, 50' of #6 I think? Used 25' for the KW-1 to get it out of the kitchen and have the other 25' for the 300G. Larger than what was on either transmitter, but the price was right (50ยข/ft) and the additional safety cushion is nice. As Chuck mentioned - we expect nothing less than a full set of pics when completed, close ups of those 833s, and good shots with filaments lit. (o: ~ Todd, KA1KAQ __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] #4 wire from mains? - they gotta be kidding
Don't be afraid to use large wire in primary feeds. I have seen the result of "skimping" with the result conduit noticeably warms after about 10 - 15 minutes of operation. The worst consequence is a power sag when the transmitter comes on with the result that in the extreme, contactors won't operate correctly. The wire tables specify the minimum wire size, especially if long runs are contemplated (fifty feet or so). You will never regret using the next size, even if it is initially more expensive. The current price of copper does not make the decision any easier. Bill - Original Message - From: "Bill Fondren" <[EMAIL PROTECTED]> To: "Discussion of AM Radio in the Amateur Service" Sent: Wednesday, May 09, 2007 8:43 PM Subject: Re: [AMRadio] #4 wire from mains? - they gotta be kidding > Brian I think u answered a lot ur questions or concerns. The transmitter was designed for 24 hour / 7 day a week operation. at 1000 watts. I agree # 4 seems overkill but Gates wanted to get as stiff a power supply to the transmitter as possible. Those transmitters were used in a lot of small towns, mom and pop operations. The old branch circuit tables showed 30 amp #10, 40 amp #8, 50 amp # 6 etc. Then down at the bottom of the page the small print said for long distance runs keep the voltage drop less than 3% by increasing wire size. Anyway from the distances u mentioned dont think u will have a problem. Dont forget to double the distance in making voltage drop calulations because the current comes in on one wire and returns on the other wire. Bill Fondren K5PML > > > "A.R.S. - W5AMI" <[EMAIL PROTECTED]> wrote: > I've been reading the Gates BC-1T manual and found two instances where > they state that #4 wire should be used. One says: > > "3) ...provide #4 or larger primary wiring from entrance box to transmitter". > > What the heck am I missing here? My 200 amp mains (as the wire runs) > to my shack junction box will be about 24 feet max, and then from the > shack panel to the Gates will be no more than 12 feet. > - - - > Brian / wa5am > > -- > Suburbia is where the developer bulldozes out the trees, then names > the streets after them. - Bill Vaughan > __ > AMRadio mailing list > List Rules (must read!): http://w5ami.net/amradiofaq.html > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Partner Website: http://www.amfone.net > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > To unsubscribe, send an email to [EMAIL PROTECTED] with > the word unsubscribe in the message body. > > > __ > AMRadio mailing list > List Rules (must read!): http://w5ami.net/amradiofaq.html > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Partner Website: http://www.amfone.net > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > To unsubscribe, send an email to [EMAIL PROTECTED] with > the word unsubscribe in the message body. __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] #4 wire from mains? - they gotta be kidding
[EMAIL PROTECTED] writes: > Actually, for this short distance, mains to shack to rigs, I could > probably get by with #8 so long as I don't run multiple KW rigs at one > time ;) #4 wire would be considerable overkill in most installation situations, but if it was a long run, in a hot environment, using old style wire, maybe in conduit, then it probably made more sense. I used a standard 10/3 molded electric dryer cord exiting through a panel bushing that already existed about halfway up the left rear of my BC-1T. Inside the rig the primary wiring is #10 as well. The rig is sitting right next to the distribution panel and the outlet is mounted on the side of the box with #10 to the breaker. You can see it in this photo pretty well... http://www.wd8das.net/Gates/restored1.jpg I do have a problem with the circuit breaker tripping off once in awhile when I key the rig. Transmitters of this sort with no step-start were intended for time-delay fuse protection, not breakers. So far I haven't found a breaker with a time-delay action for this domestic panel, so I think I need to consider step-start in the power supply. Inside the rig there are two such fuses for additional protection. Steve WD8DAS ** See what's free at http://www.aol.com. __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] #4 wire from mains? - they gotta be kidding
I believe I used #6 or #8 for mine, and even that seems like overkill. But the idea is to maintain the best line voltage regulation possible. The bigger the wire, the better. Better to have it and not need it, than to need it and not have it. But at the 1 kw power level (about 3000 watts drain off the a.c. mains) there is no need for #4 wire on a 220 volt circuit. A 110 volt circuit would be a different matter. One thing I found with the way the Gates is wired, is that it violates the electrical code. They ground the a.c. neutral directly to the transmitter cabinet. The neutral should never be strapped to ground anywhere except at one point and only one point: the ground rod located at the service entrance to the house. Inside the building past the circuit breaker box, the neutral wire should always be insulated and treated exactly the same as a hot wire. Not only is grounding the neutral dangerous and a violation of the NEC, it is an excellent way to create ground loops that result in inexplicable a.c. hum in various audio circuits. I lifted the neutral off the grounded cabinet in mine, and ran a separate ground wire from the cabinet to the electrical system ground. The danger in strapping the two together is that if the neutral wire should happen to open for any reason, the ground wire would be carrying the full neutral line current. This could result in a.c. voltage on some nominally grounded metallic objects. Of course, the Gates runs off 220 volts, so there should NORMALLY be very little if any neutral current. But I would still lift the neutral off the cabinet and ground the cabinet separately with a dedicated ground wire. Don k4kyv __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] #4 wire from mains? - they gotta be kidding
Brian I think u answered a lot ur questions or concerns. The transmitter was designed for 24 hour / 7 day a week operation. at 1000 watts. I agree # 4 seems overkill but Gates wanted to get as stiff a power supply to the transmitter as possible. Those transmitters were used in a lot of small towns, mom and pop operations. The old branch circuit tables showed 30 amp #10, 40 amp #8, 50 amp # 6 etc. Then down at the bottom of the page the small print said for long distance runs keep the voltage drop less than 3% by increasing wire size. Anyway from the distances u mentioned dont think u will have a problem. Dont forget to double the distance in making voltage drop calulations because the current comes in on one wire and returns on the other wire. Bill Fondren K5PML "A.R.S. - W5AMI" <[EMAIL PROTECTED]> wrote: I've been reading the Gates BC-1T manual and found two instances where they state that #4 wire should be used. One says: "3) ...provide #4 or larger primary wiring from entrance box to transmitter". What the heck am I missing here? My 200 amp mains (as the wire runs) to my shack junction box will be about 24 feet max, and then from the shack panel to the Gates will be no more than 12 feet. - - - Brian / wa5am -- Suburbia is where the developer bulldozes out the trees, then names the streets after them. - Bill Vaughan __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body. __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] #4 wire from mains? - they gotta be kidding
On 5/9/07, Larry Will <[EMAIL PROTECTED]> wrote: At Gates they had no idea what the branch circuit wire run distance is so they made a specification that probably could apply to worst case. I Love the Gates' manuals Larry. They are actually very good, however somewhat simplistic and even humorous on certain things like one section about powering up with both rectifiers says "..Are you feeling brave"! I think a lot of this was they wanted the users to be safe, rather than sorry, or worse, dead. Some of it is written as if some "appliance operator" would actually be doing the installation, setup, and applying power to the tower. Thanks for the thoughts! Brian __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] #4 wire from mains? - they gotta be kidding
Jim, Well its all about drop and mains "stiffness". I am sure with your short run, ampacity is all you have to worry about. My RCA BTA-1R1 manual calls for #8 for each conductor. I use #10 and my run is comparable to yours. My TX branch feed is from a submain fed with #6. The #6 run (150 amp mains) is about 60 feet and the #10 is around 25 feet. Larry Larry At 08:04 PM 5/9/2007, you wrote: Larry, my 2001 reference says 2% for voltage drop. It also says that #8 in a three wire bundle will handle 40 amps. Jim/W5JO I forgot to mention. If you size the wire for the current, the 5% rule comes in at about 125 feet IF I remember correctly. Larry W3LW __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body. __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] #4 wire from mains? - they gotta be kidding
Larry, my 2001 reference says 2% for voltage drop. It also says that #8 in a three wire bundle will handle 40 amps. Jim/W5JO I forgot to mention. If you size the wire for the current, the 5% rule comes in at about 125 feet IF I remember correctly. Larry W3LW __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] #4 wire from mains? - they gotta be kidding
At 06:59 PM 5/9/2007, you wrote: "3) ...provide #4 or larger primary wiring from entrance box to transmitter". Brain, I forgot to mention. If you size the wire for the current, the 5% rule comes in at about 125 feet IF I remember correctly. Larry W3LW __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] #4 wire from mains? - they gotta be kidding
I've been reading the Gates BC-1T manual and found two instances where > they state that #4 wire should be used. Brian, There are two considerations for wire size. See NEC Code books The first is ampacity - the current carrying requirement. The second is voltage drop - the length of the run. At Gates they had no idea what the branch circuit wire run distance is so they made a specification that probably could apply to worst case. The rule is the max voltage drop on a branch circuit (mains box to load) should never be more than 5% and probably you would like less. Larry, W3LW __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body. __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] #4 wire from mains? - they gotta be kidding
> IF YOU LOOK AT THE OLD WIRE TABLES OF THE 1950 YOU WILL FIND THE INSULATION RATINGS ABOUT 20%OR MORE LESS THAN TODAYS. I've been reading the Gates BC-1T manual and found two instances where > they state that #4 wire should be used. One says: > > "3) ...provide #4 or larger primary wiring from entrance box to > transmitter". > > The other is about carrier shift at 100% modulation: > > "9) Carrier shift: 3% or less between 0 and 100% modulation provided > wire size in point 3 (above) is followed..". > > They have got to be kidding! Of course I know this is assuming > possibly 24/7 commercial operation at the full KW, but still, #4 wire > for a 1000 watt tx, PEP of 4000 watts w/100% modulation? > > What the heck am I missing here? My 200 amp mains (as the wire runs) > to my shack junction box will be about 24 feet max, and then from the > shack panel to the Gates will be no more than 12 feet. I plan to run > #6 to the shack junction box from the 200 amp main, and then > appropriate size to certain outlets in the shack. I will likely use > #8 from the shack box through the wall to a 220 outlet for my Henry 3K > Classic-X, and #6 to the Gates on separate circuits, but will NEVER > have both of them going at the same time anyway. > > I suspect I will not use a wall outlet for the Gates and simply route > the #6 wires directly to the primary terminals in the Gates, and use > the panel breaker for emergency shutoff. > > Actually, for this short distance, mains to shack to rigs, I could > probably get by with #8 so long as I don't run multiple KW rigs at one > time ;) > > 73 > Brian / wa5am > > -- > Suburbia is where the developer bulldozes out the trees, then names > the streets after them. - Bill Vaughan > __ > AMRadio mailing list > List Rules (must read!): http://w5ami.net/amradiofaq.html > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Partner Website: http://www.amfone.net > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > To unsubscribe, send an email to [EMAIL PROTECTED] with > the word unsubscribe in the message body. > - Join ISP.COM today - $8.95 internet , less than 1/2 the cost of AOL Try us out, http://www.isp.com/ __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
