RE: [Repeater-Builder] Spinning disk wattmeter...
Yeah, that is a big issue with those big and heavy ferroresonant power supplies from GE and Motorola. At low loads, they are incredibly inefficient, with very low power factors- meaning the volt-amperes are much higher than the watts. Proof of this statement is found in the Files section of this group, in my Power Supply Load Test folder. You pay for electric energy in kilowatt-hours, kWh, not for volt-amperes. Regardless of what the ammeter reads, the Kill-A-Watt reading of 43 watts is what counts. If we assume that the repeater sits idle for 24 hours and consumes 43 watts, that is 1.032 kWh per day- probably 15 cents worth. I have one of those Kill-A-Watt meters, as well as some spinning-disk meters, and they agree very closely. Electricity suppliers don't like low power factors, because even though the power consumption may be low, the utility must build their infrastructure to supply those reactive amperes, meaning bigger generators, transformers, and power lines. Large industrial customers are often penalized for low power factor, to help pay for the additional capital equipment that must be installed to supply reactive amperes. That's why new commercial gear is using power-factor-corrected switchmode power supplies. The definition of "high power factor" varies, but most utilities want PF to be above 0.9. It should be emphasized that one cannot determine power consumed (watts) by separately measuring volts and amps. Separate measurements result in volt-amperes, which is also called "apparent power." To measure true power, one must use a wattmeter. A mechanical wattmeter is called an electrodynamometer, and is a meter that has two coils- instead of one coil and a permanent magnet. One coil is connected in parallel with the load, and is energized by voltage. The other coil is much heavier and is connected in series with the load, and is energized by current. The torque on the meter movement is the instantaneous sum of voltage and current in phase, result in a deflection indicative of power. An electronic wattmeter uses a circuit element known as a four-quadrant multiplier, meaning that the comparison of voltage and current is continuous through 360 degrees. I have just such an instrument, a WD-767 digital wattmeter made by VIZ. It can display true-RMS volts, true-RMS current, and true power in watts. Very handy! 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Mike Morris WA6ILQ Sent: Sunday, October 04, 2009 6:10 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Spinning disk wattmeter... A ham I know is doing some research and needs to locate a spinning disk KWH meter, with socket, cheap or free... If he turns up something interesting it will end up as a repeater-builder article. He wrote: >My concern is that the cabinet I had here last year measured at idle >1.5 amps at 120V (180VA) yet also only measured 43 Watts with >the Kill-A-Watt meter. I am looking for another device to tell me what >the electric company is actually seeing and billing. Might one of your >connections have an extra single phase KWH meter in the junk box? I suspect he has a situation involving power factor. Mike WA6ILQ
Re: [Repeater-Builder] Spinning disk wattmeter...
There is a device called a Kill a watt, that is a plug in kWh meter, should be avalible at big hardware stores. http://www.killawattplus.com On Sun, Oct 4, 2009 at 6:57 PM, Eric Lemmon wrote: > Yeah, that is a big issue with those big and heavy ferroresonant power > supplies from GE and Motorola. At low loads, they are incredibly > inefficient, with very low power factors- meaning the volt-amperes are much > higher than the watts. Proof of this statement is found in the Files > section of this group, in my Power Supply Load Test folder. > > You pay for electric energy in kilowatt-hours, kWh, not for volt-amperes. > Regardless of what the ammeter reads, the Kill-A-Watt reading of 43 watts is > what counts. If we assume that the repeater sits idle for 24 hours and > consumes 43 watts, that is 1.032 kWh per day- probably 15 cents worth. I > have one of those Kill-A-Watt meters, as well as some spinning-disk meters, > and they agree very closely. > > Electricity suppliers don't like low power factors, because even though the > power consumption may be low, the utility must build their infrastructure to > supply those reactive amperes, meaning bigger generators, transformers, and > power lines. Large industrial customers are often penalized for low power > factor, to help pay for the additional capital equipment that must be > installed to supply reactive amperes. That's why new commercial gear is > using power-factor-corrected switchmode power supplies. The definition of > "high power factor" varies, but most utilities want PF to be above 0.9. > > It should be emphasized that one cannot determine power consumed (watts) by > separately measuring volts and amps. Separate measurements result in > volt-amperes, which is also called "apparent power." To measure true power, > one must use a wattmeter. A mechanical wattmeter is called an > electrodynamometer, and is a meter that has two coils- instead of one coil > and a permanent magnet. One coil is connected in parallel with the load, > and is energized by voltage. The other coil is much heavier and is > connected in series with the load, and is energized by current. The torque > on the meter movement is the instantaneous sum of voltage and current in > phase, result in a deflection indicative of power. An electronic wattmeter > uses a circuit element known as a four-quadrant multiplier, meaning that the > comparison of voltage and current is continuous through 360 degrees. I have > just such an instrument, a WD-767 digital wattmeter made by VIZ. It can > display true-RMS volts, true-RMS current, and true power in watts. Very > handy! > > 73, Eric Lemmon WB6FLY > > > -Original Message- > From: Repeater-Builder@yahoogroups.com > [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Mike Morris WA6ILQ > Sent: Sunday, October 04, 2009 6:10 PM > To: Repeater-Builder@yahoogroups.com > Subject: [Repeater-Builder] Spinning disk wattmeter... > > > > A ham I know is doing some research and needs to > locate a spinning disk KWH meter, with socket, cheap > or free... > > If he turns up something interesting it will end up as a > repeater-builder article. > > He wrote: > >>My concern is that the cabinet I had here last year measured at idle >>1.5 amps at 120V (180VA) yet also only measured 43 Watts with >>the Kill-A-Watt meter. I am looking for another device to tell me what >>the electric company is actually seeing and billing. Might one of your >>connections have an extra single phase KWH meter in the junk box? > > I suspect he has a situation involving power factor. > > Mike WA6ILQ > > > > > > > > > > > > Yahoo! Groups Links > > > >
Re: [Repeater-Builder] Spinning disk wattmeter...
At 06:34 PM 10/04/09, you wrote: >I have one that I use every once in a while. It works well at >determining the power usage of a repeater at a site. I don't want >to give mine away, but I would lend it out to you. I will want it >back, though. It weighs about 15 pounds, so shipping and the >eventual return shipment may be more than he wants to spend. I appreciate the "loan" offer, both from you and from several others, but I think that he (or I) will want it around for making measurements in the future. >I found mine at the dump. It is a 120VAC 15 Ampere, 60 cycle, >2-wire unit. I even got the box with it, and I put an AC cord and >plug on the box. This evidently came off one of the old summer >homes that are around the local lakes of Connecticut. Many of these >summer homes were very small and sparse, no heat not running water, >from the 1920's and up in time. Electricity was a luxury and they >did have 15 Amp services. That's exactly what we need - a four-wire meter (120V in, neutral in, 120V out, neutral out) at anywhere from 15 to 60 amps. And I've seen one that looked like it had three wires (in out and neutral), but I never saw it in operation. >Maybe a local electrician around your area may have run into >something similar out where you are? This request came in saturday morning, I spent all day saturday on a deployment, and not many electricians are in their offices / shops on a sunday... I'll ask around during the week. >73, Joe, K1ike Mike WA6ILQ
Re: [Repeater-Builder] Spinning disk wattmeter...
I bought some off ebay a couple years ago I think this is the same guy. I have $25.00 into mine so it would be cheeper to get yours directly from him. tom http://cgi.ebay.com/single-GE-I70-meter-watthour-watt-electric-utility_W0QQi temZ250505742954QQcmdZViewItemQQptZBI_Electrical_Equipment_Tools?hash=item3a 534e4a6a&_trksid=p3286.c0.m14 > [Original Message] > From: Mike Morris WA6ILQ > To: > Date: 10/5/2009 3:17:23 AM > Subject: Re: [Repeater-Builder] Spinning disk wattmeter... > > At 06:34 PM 10/04/09, you wrote: > >I have one that I use every once in a while. It works well at > >determining the power usage of a repeater at a site. I don't want > >to give mine away, but I would lend it out to you. I will want it > >back, though. It weighs about 15 pounds, so shipping and the > >eventual return shipment may be more than he wants to spend. > > I appreciate the "loan" offer, both from you and from > several others, but I think that he (or I) will want it > around for making measurements in the future. > > >I found mine at the dump. It is a 120VAC 15 Ampere, 60 cycle, > >2-wire unit. I even got the box with it, and I put an AC cord and > >plug on the box. This evidently came off one of the old summer > >homes that are around the local lakes of Connecticut. Many of these > >summer homes were very small and sparse, no heat not running water, > >from the 1920's and up in time. Electricity was a luxury and they > >did have 15 Amp services. > > That's exactly what we need - a four-wire meter (120V in, neutral in, > 120V out, neutral out) at anywhere from 15 to 60 amps. And I've seen > one that looked like it had three wires (in out and neutral), but I never > saw it in operation. > > >Maybe a local electrician around your area may have run into > >something similar out where you are? > > This request came in saturday morning, I spent all day > saturday on a deployment, and not many electricians > are in their offices / shops on a sunday... I'll ask around > during the week. > > >73, Joe, K1ike > > Mike WA6ILQ > > > > > > > > > Yahoo! Groups Links > > >
Re: [Repeater-Builder] Spinning disk wattmeter...
Go buy yourself a Kill-A-Watt...less than $30. Has several modes, e.g., voltage, frequency, average power, peak power,etc. and works great for the price. de WD7F John in Tucson - Original Message - From: "Thomas Oliver" To: Sent: Monday, October 05, 2009 7:31 AM Subject: Re: [Repeater-Builder] Spinning disk wattmeter... >I bought some off ebay a couple years ago I think this is the same guy. > > I have $25.00 into mine so it would be cheeper to get yours directly from > him. > > tom > > http://cgi.ebay.com/single-GE-I70-meter-watthour-watt-electric-utility_W0QQi > temZ250505742954QQcmdZViewItemQQptZBI_Electrical_Equipment_Tools?hash=item3a > 534e4a6a&_trksid=p3286.c0.m14 > > >> [Original Message] >> From: Mike Morris WA6ILQ >> To: >> Date: 10/5/2009 3:17:23 AM >> Subject: Re: [Repeater-Builder] Spinning disk wattmeter... >> >> At 06:34 PM 10/04/09, you wrote: >> >I have one that I use every once in a while. It works well at >> >determining the power usage of a repeater at a site. I don't want >> >to give mine away, but I would lend it out to you. I will want it >> >back, though. It weighs about 15 pounds, so shipping and the >> >eventual return shipment may be more than he wants to spend. >> >> I appreciate the "loan" offer, both from you and from >> several others, but I think that he (or I) will want it >> around for making measurements in the future. >> >> >I found mine at the dump. It is a 120VAC 15 Ampere, 60 cycle, >> >2-wire unit. I even got the box with it, and I put an AC cord and >> >plug on the box. This evidently came off one of the old summer >> >homes that are around the local lakes of Connecticut. Many of these >> >summer homes were very small and sparse, no heat not running water, >> >from the 1920's and up in time. Electricity was a luxury and they >> >did have 15 Amp services. >> >> That's exactly what we need - a four-wire meter (120V in, neutral in, >> 120V out, neutral out) at anywhere from 15 to 60 amps. And I've seen >> one that looked like it had three wires (in out and neutral), but I never >> saw it in operation. >> >> >Maybe a local electrician around your area may have run into >> >something similar out where you are? >> >> This request came in saturday morning, I spent all day >> saturday on a deployment, and not many electricians >> are in their offices / shops on a sunday... I'll ask around >> during the week. >> >> >73, Joe, K1ike >> >> Mike WA6ILQ >> >> >> >> >> >> >> >> >> Yahoo! Groups Links >> >> >> > > > > > > > > Yahoo! Groups Links > > > No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.409 / Virus Database: 270.14.3/2414 - Release Date: 10/04/09 18:42:00
RE: [Repeater-Builder] Spinning disk wattmeter...
P3 Kill A Watt Electricity Load Meter and Monitor $19 from Newegg: http://www.newegg.com/Product/Product.aspx?Item=N82E16882715001 Free Shipping after Coupon Code: EMCLXNX64 (Exp 10/5). Doug K4AC From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of WD7F - John in Tucson Sent: Monday, October 05, 2009 10:52 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Spinning disk wattmeter... Go buy yourself a Kill-A-Watt...less than $30. Has several modes, e.g., voltage, frequency, average power, peak power,etc. and works great for the price. de WD7F John in Tucson
Re: [Repeater-Builder] Spinning disk wattmeter...
The original post indicated that the guy already has one of these meters. Chuck WB2EDV - Original Message - From: Doug Rehman To: Repeater-Builder@yahoogroups.com Sent: Monday, October 05, 2009 11:08 AM Subject: RE: [Repeater-Builder] Spinning disk wattmeter... P3 Kill A Watt Electricity Load Meter and Monitor $19 from Newegg: http://www.newegg.com/Product/Product.aspx?Item=N82E16882715001 Free Shipping after Coupon Code: EMCLXNX64 (Exp 10/5). Doug K4AC From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of WD7F - John in Tucson Sent: Monday, October 05, 2009 10:52 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Spinning disk wattmeter... Go buy yourself a Kill-A-Watt...less than $30. Has several modes, e.g., voltage, frequency, average power, peak power,etc. and works great for the price. de WD7F John in Tucson
Re: [Repeater-Builder] Spinning disk wattmeter...
Hey, It is good enough for the Mythbusters On Mon, Oct 5, 2009 at 8:14 AM, Chuck Kelsey wrote: > > > The original post indicated that the guy already has one of these meters. > > Chuck > WB2EDV > > > > > - Original Message - > *From:* Doug Rehman > *To:* Repeater-Builder@yahoogroups.com > *Sent:* Monday, October 05, 2009 11:08 AM > *Subject:* RE: [Repeater-Builder] Spinning disk wattmeter... > > P3 Kill A Watt Electricity Load Meter and Monitor $19 from Newegg: > http://www.newegg.com/Product/Product.aspx?Item=N82E16882715001 > > > > *Free Shipping* after Coupon Code: *EMCLXNX64* (Exp 10/5). > > > > Doug > > K4AC > > > > *From:* Repeater-Builder@yahoogroups.com [mailto: > repeater-buil...@yahoogroups.com] *On Behalf Of *WD7F - John in Tucson > *Sent:* Monday, October 05, 2009 10:52 AM > *To:* Repeater-Builder@yahoogroups.com > *Subject:* Re: [Repeater-Builder] Spinning disk wattmeter... > > > > > > Go buy yourself a Kill-A-Watt...less than $30. Has several modes, e.g., > voltage, frequency, average power, peak power,etc. and works great for the > price. > de WD7F > John in Tucson > > > > >
