There are ways to extend your existing service panel for more breakers, if the service to the panel is sufficient (and already 200A service), by simply installing a sub-panel. Cheaper and less work than replacing the panel. But to be safe and in conformance, you'd have to confirm the panel service is adequate.
Of course in the "real world" it would be very rare at a residence to max out the service drop since we almost never (and usually, literally never) use all appliances at once. For safety and fire prevention, stuff's rated as though it is all being used at once, which is a good idea and of course it "might be."
But in my case, for example, the pool pumps only run 6AM to noon every day, and although they draw about 40A when running, when they're not running they draw nothing. So if I wanted to sub some other 40A appliance between noon and 6AM, I wouldn't be overloading anything. My spa heater is on a timer and it runs 2 hours per day, between 3AM and 5AM. It draws 20A and keeps the spa (with the cover on) at 105F all the time. So there's another 20A available at all hours except those. I have an electric cooktop which, which all burners running, can draw 40A at 240V. But I've never, ever, even once used all the burners. It's possible to do that, but we just never do. So, there's surplus power there.
The air conditioning draws close to 40A when it's running full tilt, but that only happens in the summertime (and maybe a bit in the spring and fall) and virtually never in the winter. So, there's 40A available in wintertime, anyway.
It's all a bit overkill for most, like you and me. You'd probably be very safe running a sub-panel, which if you do it yourself costs about $50.
Sounds nice. Here in the summertime it is so humid that some days both heat-pumps are running continuously, but since they tie in outside I don't believe the 100A sub-panel is affected. Same story in mid-winter though much less often, if the outside temperature drops much below freezing, both heat pumps will have the auxiliary heating elements kick in. But most of the year it is mild and neither heat pump is actually running much.
And I wouldn't be running more than one of the dryer, stove, or amplifier at a time.
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73, Peter N4UP
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A gentleman is a man who can play the accordion but doesn't.
Duct tape is like the force. It has a light side, a dark side, and it holds the universe together. ~Carl Zwanzig
Just an update. For now I am using the 120V 20A dedicated line. So far no problems running the amplifier at 450W. Will be gradually increasing to 1000W to check for RFI. The drain voltage does drop during transmission, as expected, but it stays within the "green" zone. So far so good.
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73, Peter N4UP
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A gentleman is a man who can play the accordion but doesn't.
Duct tape is like the force. It has a light side, a dark side, and it holds the universe together. ~Carl Zwanzig
If you have a 200A drop and only a 100A panel, I vote for upgrading panel to 200A and forever be done with the issue. Your electrician's hourly rate is a bargain.
Yes, that seems to be the consensus. I will bring the electrician back to do the upgrade.
But here's a question I should know the answer to before he comes back, as I figure you guys know more about this than he does ( and more than me ) ...
After he upgrades the panel, can he use the same Romex 12-2 cable ( with ground ) from the radio room to a 240V breaker? Or would he need to thread a 12-3 cable ( with ground ) from the radio room to the breaker?
And on the radio end of things --- The amplifier has a three-prong IEC320C13 connector for either 120V or 240V so I assume we wouldn't need 12-3?
Now I am NOT the expert on any of this, but I believe the IEC320C13 amplifier connector is common on 120V appliances ( computers, monitors, printers, radio equipment, etc. ) and I have been unable to find a cable anywhere that goes from any "normal" 240V outlet to the IEC320C13. So I could ( a ) keep the existing 120V 20A outlet but wire it to a 240V breaker and switch the amplifier to 240V OR ( b ) replace the 120V outlet with a 240V outlet and buy a 240V plug and solder the three leads from the IEC320C13 to the 240V plug. I'm guessing ( a ) is dumb and I should go with ( b ).
It just seems strange that the amplifier would have that connector in the first place. i.e., a common 120V connector to be used for either 120V or 240V.
I finally got the right image to insert, but now I am stuck with two "attachments" that I don't know how to delete.
Last edited by N4UP; 06-12-2012 at 04:23 PM.
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73, Peter N4UP
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A gentleman is a man who can play the accordion but doesn't.
Duct tape is like the force. It has a light side, a dark side, and it holds the universe together. ~Carl Zwanzig
As long as the 120v line he ran originally is "dedicated" to that one outlet you have for the amp now AND he did not add any other 120v outlets on the same feed, then all he has to do is remove the white wire from the neutral bar and add a 2 dpole 240v 20A breaker and convert the line to a dedicated 240v line. Then change the outlet on the end to a 240v style outlet. Get a matching plug for the outlet and cut the plug off the amp and put the new 240v plug on it. Then go inside the amp and make the 240v change according to the manual. You DO NOT need a new cord on the amp, just a plug.
As long as the 120v line he ran originally is "dedicated" to that one outlet you have for the amp now AND he did not add any other 120v outlets on the same feed, then all he has to do is remove the white wire from the neutral bar and add a 2 dpole 240v 20A breaker and convert the line to a dedicated 240v line. Then change the outlet on the end to a 240v style outlet. Get a matching plug for the outlet and cut the plug off the amp and put the new 240v plug on it. Then go inside the amp and make the 240v change according to the manual. You DO NOT need a new cord on the amp, just a plug.
Thank you. That makes sense to me. He did not run any other outlets on the new feed to the radio room. So will plan to do as you advise.
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73, Peter N4UP
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A gentleman is a man who can play the accordion but doesn't.
Duct tape is like the force. It has a light side, a dark side, and it holds the universe together. ~Carl Zwanzig
Yes, that seems to be the consensus. I will bring the electrician back to do the upgrade.
But here's a question I should know the answer to before he comes back, as I figure you guys know more about this than he does ( and more than me ) ...
After he upgrades the panel, can he use the same Romex 12-2 cable ( with ground ) from the radio room to a 240V breaker? Or would he need to thread a 12-3 cable ( with ground ) from the radio room to the breaker?
And on the radio end of things --- The amplifier has a three-prong IEC320C13 connector for either 120V or 240V so I assume we wouldn't need 12-3?
Now I am NOT the expert on any of this, but I believe the IEC320C13 amplifier connector is common on 120V appliances ( computers, monitors, printers, radio equipment, etc. ) and I have been unable to find a cable anywhere that goes from any "normal" 240V outlet to the IEC320C13. So I could ( a ) keep the existing 120V 20A outlet but wire it to a 240V breaker and switch the amplifier to 240V OR ( b ) replace the 120V outlet with a 240V outlet and buy a 240V plug and solder the three leads from the IEC320C13 to the 240V plug. I'm guessing ( a ) is dumb and I should go with ( b ).
It just seems strange that the amplifier would have that connector in the first place.
I finally got the right image to insert, but now I am stuck with two "attachments" that I don't know how to delete.
Here you go.
Elecarft sells one for their KPA500.
PWR-US240 IEC-U.S. 240V Power Cord w/fuses (NEMA 6-15P suitable for 6-15R and 6-20R receptacles
CW is a manually controlled, message asynchronous, simplex chat mode used without FEC.
"The democracy will cease to exist when you take away from those who are willing to work and give to those who would not." -- Thomas Jefferson
Now I understand why my search failed. I was searching "240V IEC" when I should have been searching "NEMA 6-15 IEC" ... It sure helps to know the correct terminology. And it sure helps to be on QRZ forums. Thanks Very.
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73, Peter N4UP
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A gentleman is a man who can play the accordion but doesn't.
Duct tape is like the force. It has a light side, a dark side, and it holds the universe together. ~Carl Zwanzig
May I suggest that you tap the line to a seldom used 240 volt appliance, a cloths dryer for instance. I would assume that cloths dryer is on its own circuit.
The only time that you couldn't operate is when the dryer is on. Maybe you only operate at night
Code around here requires Electric dryer be on a dedicated line. Need to look into that before going that route.
Originally Posted by WB2WIK
There are ways to extend your existing service panel for more breakers, if the service to the panel is sufficient (and already 200A service), by simply installing a sub-panel. Cheaper and less work than replacing the panel. But to be safe and in conformance, you'd have to confirm the panel service is adequate.
