Elecraft

KPA-500 110 or 220?

Classic

List

Threaded

10 messages Options

Richard Fjeld

KPA-500 110 or 220?

Bill wrote;

I would like to hear opinions on if it makes any difference to configure the
KPA-500 for 220 volts? Is it any more efficient? Seems to me that 110
would be the way to go for portability as long as efficiency is the same or
nearly the same.

73 Bill NZ0T
________________

I have read that an Electric Meter (wattage meter) will run up the bill more if the load is not balanced across the two feeders in the meter. By running things on 220 Volts when possible, it may help to balance the load and the meter becomes more efficient for the consumer. YMMV

Richard Fjeld, N0CE

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

WB4SON

Re: KPA-500 110 or 220?

Electric meters measure current consumption on both 120v legs when
calculating total watt hour consumption. So it matters not one bit if the
loads are balanced or unbalanced from a billing point of view. Rumors to
the contrary are simply not correct.

The reason for running the amplifier at a higher voltage is that it will
reduce the IR voltage drop. Because the operating voltage has doubled, the
required current has been cut in half. Therefore the IR drop (loss in the
wiring) has been cut in half.

73, Bob, WB4SON
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

73, Bob, WB4SON

Milt -- N5IA

Re: KPA-500 110 or 220?

In reply to this post by Richard Fjeld

-----Original Message-----
From: Richard Fjeld
Sent: Monday, August 06, 2012 9:53 AM
To: elecraft posting
Subject: [Elecraft] KPA-500 110 or 220?

I have read that an Electric Meter (wattage meter) will run up the bill more
if the load is not balanced across the two feeders in the meter. By running
things on 220 Volts when possible, it may help to balance the load and the
meter becomes more efficient for the consumer. YMMV

Richard Fjeld, N0CE

-------------------------------------------

NOT TRUE!!!!!!!!!!!!!

The kWh (kiloWatt hour = energy consumed [thousands of Watts] over a period
of time [an hour]) meters are NOT designed in that manner. And, your Public
Utility Commission (PUC) would NOT approve them for use if they were design
defective in that manner.

PUCs require periodic testing of ALL kWh meters to assure they are
registering power consumed, within the State specified range (typically +-
1.5%), for loading across a single leg (120 V) or across both legs (240 V).

In the past (and where they are still used) the electro-mechanical kWh meter
typically would slowly slow down over time due to wear on the disc jewels
and spindle, or due to dust affecting those same points. Most meters found
out of tolerance are running SLOWWWWWER; an advantage to the consumer. But,
the percentage of kWh meters found out of tolerance during routine testing
is very small (less than 1 percent). And that 'out of tolerance' value
typically is less than 2 percent. The electro-mechanical kWh meter is truly
a marvel. It is a highly accurate, long lived instrument which operates in
a relatively hostile environment for years without requiring maintenance.

Today's electronic kWh meters overcome the wear/dust problem as there are no
moving parts. However, change of component values over time may cause
similar problems; either under registering or over registering. So,
periodic testing of kWh meters is still mandatory. The main advantage of
electronic meters is the capability of including remote reading, load
monitoring, etc., which all contribute to a more efficient, accurate (no
manual meter reading person) and less costly operation.

Mis dos centavos.

de Milt, N5IA

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Jim Brown-10

Re: KPA-500 110 or 220?

In reply to this post by WB4SON

On 8/6/2012 11:21 AM, Ron D'Eau Claire wrote:
> If the voltage rises too much the amp will shut itself down to prevent
> damage. If the key down voltage drops below 60V IMD increases and the
> maximum power available may be less than 500 watts.

This mostly an issue on 6M, where the output devices are least
efficient, and thus requiring the most current to produce rated output.
I get 540W out on 6M running from a 20A 120V circuit, and the DC voltage
is a bit below the 60V keydown. I could probably get 600W by going to
240V, and the devices would probably run a bit cooler. One of these
days I may do that -- I have 240V in the shack for my Titan amps.

73, Jim K9YC
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

MontyS

Re: KPA-500 110 or 220?

In reply to this post by WB4SON

Actually it's "I-squared R drop", and a 1/2 reduction in current results in a 75% loss reduction.
Monty K2DLJ

On Aug 6, 2012, at 1:27 PM, Bob <[hidden email]> wrote:

> Electric meters measure current consumption on both 120v legs when
> calculating total watt hour consumption. So it matters not one bit if the
> loads are balanced or unbalanced from a billing point of view. Rumors to
> the contrary are simply not correct.
>
> The reason for running the amplifier at a higher voltage is that it will
> reduce the IR voltage drop. Because the operating voltage has doubled, the
> required current has been cut in half. Therefore the IR drop (loss in the
> wiring) has been cut in half.
>
> 73, Bob, WB4SON
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

vk4tux

Re: KPA-500 110 or 220?

E=IR in a circuit. To determine volt drop in a circuit it is a simple
circuit resistance multiplied by the current. Simple ohms law and nothing
squared.
Bob refers to IR loss in the circuit feeding the amp as per above line and
not meter efficiency equations.

Circuit; 1 ohm x 20 amp = 20v volt drop (120v)

To halve current we doubled the voltage and reduced load by half with the
same circuit(tap change etc).

Circuit; 1 ohm x 10 amp = 10v volt drop (240v)

Looks like a 50% loss(read reduction in volt drop) with current halved not
75%

As far as power improvement(You see I removed the voltdrop at load end
equation);

100 x 20 = 2000w

230 x 10 = 2300w

So a 300w or 15% power improvement, and a much higher IMD improvement no
doubt.

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Monty Shultes
Sent: Tuesday, 7 August 2012 5:00 AM
To: [hidden email]
Subject: Re: [Elecraft] KPA-500 110 or 220?

Actually it's "I-squared R drop", and a 1/2 reduction in current results in
a 75% loss reduction.
Monty K2DLJ

On Aug 6, 2012, at 1:27 PM, Bob <[hidden email]> wrote:

> Electric meters measure current consumption on both 120v legs when
> calculating total watt hour consumption. So it matters not one bit if
> the loads are balanced or unbalanced from a billing point of view.
> Rumors to the contrary are simply not correct.
>
> The reason for running the amplifier at a higher voltage is that it
> will reduce the IR voltage drop. Because the operating voltage has
> doubled, the required current has been cut in half. Therefore the IR
> drop (loss in the
> wiring) has been cut in half.
>
> 73, Bob, WB4SON
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net Please help support this email
> list: http://www.qsl.net/donate.html

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Don Wilhelm-4

Re: KPA-500 110 or 220?

In reply to this post by MontyS

The thing that matters is the voltage reduction under load.
"IR" is correct for the voltage reduction.
"I squared R" would represent the power reduction from the power panel
to the shack.

73,
Don W3FPR

On 8/6/2012 2:59 PM, Monty Shultes wrote:
> Actually it's "I-squared R drop", and a 1/2 reduction in current results in a 75% loss reduction.
> Monty K2DLJ
>
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Eric Swartz - WA6HHQ

Re: KPA-500 110 or 220?

Administrator

Let's end this thread at this time.

73,

Eric
---
www.elecraft.com

On 8/6/2012 1:43 PM, Don Wilhelm wrote:

> The thing that matters is the voltage reduction under load.
> "IR" is correct for the voltage reduction.
> "I squared R" would represent the power reduction from the power panel
> to the shack.
>
> 73,
> Don W3FPR
>
> On 8/6/2012 2:59 PM, Monty Shultes wrote:
>> Actually it's "I-squared R drop", and a 1/2 reduction in current results in a 75% loss reduction.
>> Monty K2DLJ
>>
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

Jim Brown-10

Re: KPA-500 110 or 220?

In reply to this post by MontyS

On 8/6/2012 11:59 AM, Monty Shultes wrote:
> "I-squared R drop",

I'm sorry, but you are mistaken. Voltage drop is IR. The POWER lost in
the resistance of the wire is I squared R.

To complicate things even more, the current drawn by any power supply
with a capacitive input filter is a pulse, not a sine wave, so the power
is the INTEGRAL of the current squared. The current is a pulse because
it must recharge the filter cap on each cycle, and most of the current
flows at the positive and negative peaks of each cycle.

The impulsive nature of the current causes the 60 Hz sine wave to be
distorted, creating harmonic distortion. That's why power line leakage
current is heard as "buzz" (the harmonics of 60 Hz) rather than "hum"
(pure 60 Hz). AND the impulsive nature of leakage current increases the
power lost beyond what would be predicted by simple Ohm's law applied to
a 60 Hz sine wave -- there's much more power lost at the peaks of the
charging cycle.

73, Jim K9YC
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Richard Fjeld

Re: KPA-500 110 or 220?

In reply to this post by Milt -- N5IA

Unfortunately, I do not have the article, and it was before internet (BI).
I tried to Google it, but found nothing that addressed an unbalanced load.
I don't trust everything I read, but the article was convincing. Enough so,
that I remember it well after many years. But, as a boss once told me,
"if you don't have it documented on paper, it didn't happen". Put this in
the FWIW dept.

Rich, N0CE

----- Original Message -----
From: "Milt -- N5IA" <[hidden email]>
To: "Richard Fjeld" <[hidden email]>; "elecraft posting"
<[hidden email]>
Sent: Monday, August 06, 2012 1:11 PM
Subject: Re: [Elecraft] KPA-500 110 or 220?

> -----Original Message-----
> From: Richard Fjeld
> Sent: Monday, August 06, 2012 9:53 AM
> To: elecraft posting
> Subject: [Elecraft] KPA-500 110 or 220?
>
> I have read that an Electric Meter (wattage meter) will run up the bill
> more if the load is not balanced across the two feeders in the meter. By
> running things on 220 Volts when possible, it may help to balance the load
> and the meter becomes more efficient for the consumer. YMMV
>
> Richard Fjeld, N0CE
>
> -------------------------------------------
>
> NOT TRUE!!!!!!!!!!!!!
>
> The kWh (kiloWatt hour = energy consumed [thousands of Watts] over a
> period of time [an hour]) meters are NOT designed in that manner. And,
> your Public Utility Commission (PUC) would NOT approve them for use if
> they were design defective in that manner.
>
> PUCs require periodic testing of ALL kWh meters to assure they are
> registering power consumed, within the State specified range (typically +-
> 1.5%), for loading across a single leg (120 V) or across both legs (240
> V).
>
> In the past (and where they are still used) the electro-mechanical kWh
> meter typically would slowly slow down over time due to wear on the disc
> jewels and spindle, or due to dust affecting those same points. Most
> meters found out of tolerance are running SLOWWWWWER; an advantage to the
> consumer. But, the percentage of kWh meters found out of tolerance during
> routine testing is very small (less than 1 percent). And that 'out of
> tolerance' value typically is less than 2 percent. The electro-mechanical
> kWh meter is truly a marvel. It is a highly accurate, long lived
> instrument which operates in a relatively hostile environment for years
> without requiring maintenance.
>
> Today's electronic kWh meters overcome the wear/dust problem as there are
> no moving parts. However, change of component values over time may cause
> similar problems; either under registering or over registering. So,
> periodic testing of kWh meters is still mandatory. The main advantage of
> electronic meters is the capability of including remote reading, load
> monitoring, etc., which all contribute to a more efficient, accurate (no
> manual meter reading person) and less costly operation.
>
> Mis dos centavos.
>
> de Milt, N5IA
>