rallyrocks
fully equipped rock polisher
Member since November 2005
Posts: 1,507
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Post by rallyrocks on Jan 25, 2011 20:35:35 GMT -5
Thanks Rodney, yep I have a good breaker at the end of the cord. a circuit breaker, no matter how "good" is NOT a GFCI. If you don't have a proper GFCI on this circuit you are risking electrocution- a circuit breaker won't trip until it's rated current is exceeded for some amount of time- a lot more current and a time far longer than it takes to get killed if you are stuck with current being routed through your heart. A GFCI equipped extension cord should be available for about $30, I would not run any appliances with water on anything else...
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spokanetim
has rocks in the head
Member since October 2009
Posts: 656
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Post by spokanetim on Jan 25, 2011 21:15:03 GMT -5
Thanks guys, today I sank another $200 into a new Leeson 1 hp, high tourqe, farm duty, sealed, outdoor motor. It should get here next week and than I'll see what that will do.
On a positive note I had ordered some cheep Chinese 14" blades that got here today. I replaced the Covington Gold blade, took off the spring and added 4 lb's of weight to the cutting arm (my rock hammer). With the new blade and weight it chewed threw 10 4x4" jasper slabs without to much problem. New blade still looks good.
It really needs the bigger motor because any more weight and it would have bogged out. According to Rich's calculations I should at least doubling the weight on the arm especially at the start of the cut. When I get the new motor I'll try to mount it more forward.
Tim
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Post by deb193redux on Jan 25, 2011 23:18:31 GMT -5
Life line is A GFCI. Thay`ll trip at 100th of a mill amp. a GFI trips at a 10th amp. Hart failure is about 8th of amp. So plug life in to a real GFCI. that's rate`ed by SAIF I think you are using GFI for ordinary breaker. To my understanding GFI and GFCI are the same thing. www.thecircuitdetective.com/gfis.htm
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Post by deb193redux on Jan 26, 2011 0:15:00 GMT -5
maybe you could comment on the link, or give a link to back up the difference you assert. like you said, it is a serious matter, and accuracy is important
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spokanetim
has rocks in the head
Member since October 2009
Posts: 656
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Post by spokanetim on Jan 26, 2011 1:30:34 GMT -5
It's all ok, I'm not going to use it again till I get the new sealed motor.
That said I believe my saw is going to not work with water. I contacted MK Diamond to ask about their 14" turbo blade. The rep I spoke with was very helpful and as luck would have it his brother is a manager at Barranca Diamond, the makers of the new HP saws. I've e-mailed them much of the same info and here is their response.
"I visited Val Carver at Minnesota Lapidary last August at his shop near the Twin Cities, he said without a doubt and I agree from my own conversations with many commercial lapidarists from the Pacific Northwest at the Madras Show each July and during the Quartzsite-Tucson shows its next to impossible to expect any diamond blade to cut dense cryptocrystalline silica like Brazilian and Montana agates, thunder eggs, jaspers, geodes, jade etc. using water or water based coolants with any saw with a 12" in diameter (even the folks with 10" power feed saws have a problem cutting with water). Problem with tile blades like MK415 is that the bond just isn't formulated for many of the dense high silica gemstones and it'll require frequent blade sharpening. The Japanese, Koreans, Germans and even the De Beers folks who make industrial diamonds and blades tell me only petroleum based lubricants like mineral and machining oils seem to cut best and promote the longest blade life as the oil tends to draw away the buildup of heat off the cutting matrix of the blade kerf (edge) metals namely nickel-tungsten carbide-silver as the diamonds conduct and transmit heat from the molecular abrasion and for whatever reason oil and its slipperiness properties tends to work best just like in your engine of your car. When I worked in gold mining and exploration in the 1980s thru 1997, the diamond core drillers always told me that use of highly refined machining mineral petroleum based oils worked best down the hole where the diamond studded bits had to cut continuously at low speeds to keep the bit head cool. Even the petroleum exploration drills use oil down the hole in some cases but they've moved to synthetics due to environment concerns about ground water contamination."
So, I guess I'll either have to switch it back to oil with a pump or ditch the project and cut my losses.
Tim
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Post by parfive on Jan 26, 2011 2:17:29 GMT -5
Jack, lapidaryrough: Hogwash!! deb193redux: You’re correct on GFCI and GFI being the same thing, but for the typo.
A Class A (designed to protect people) GFI/GFCI will trip in the range of 4 mA – 6 mA (milliamps). So call it 0.005 amps.
That requirement is in the National Electrical Code. Devices are tested and listed by Underwriters Laboratories, UL.
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Post by Jack, lapidaryrough on Jan 26, 2011 11:29:28 GMT -5
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Post by deb193redux on Jan 26, 2011 12:45:13 GMT -5
Jack thanks for the links, but it is just not clear what you are reading. Looking at the links you provide, they both refer to a typical sensitivity (required by codes) of 5 mA A typical circuit breaker interrupts the circuit at 20 amperes, but it takes only about 100 milliamperes to electrocute a person in such a scenario. The GFI is designed to detect currents of a few milliamperes and trip a breaker at the receptacle or at the breaker panel to remove the shock hazard.
...The UL requirement for a GFI is that it trip when there is 5 mA of leakage current.
The only reference to 100 mA is what it takes to electrocute someone. Nowhere, nohow do these links say GFI=100 and GFCI=5 - so I repeat my original statement that GFCI=GFI, and speculate you were confused between GFI and a normal circuit breaker. Since electricity is serious, and people read this board for advice, I think we need to correct misstatements when they crop up.
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Post by parfive on Jan 26, 2011 15:31:56 GMT -5
Class A GFI/GFCI protect people, 4-6 mA trip Class B GFI/GFCI protect equipment, typically 20 or 30 mA trip
Apparently, some try to make that distinction by using GFCI for Class A and GFI for Class B. That is wrong, the distinction is Class A or Class B, not GFCI or GFI.
Besides which, Class B GFI/GFCIs are properly called GFPE or GFPD, Ground-Fault Protection of Equipment/Device.
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