Is 250 VAC too high for my 220 stuff? - Page 2

Xringer · 11-30-10, 10:23 AM

This morning, I saw 128vac with peaks up to 129vac (258vac on the 220 line)..

I called the NStar service line and the truck came out.
He drove around measured 127 (254) for a few miles around here..
Woburn, Burlington & Lexington on the same section of grid.

Not much they can do I guess. The 'engineers' told him to take out some capacitors
on our local transformer. Now we are getting 125.. 250.. Under the Sanyo 253 spec!!

Doing some testing now.. Need to heat up this cool house!

Daox · 11-30-10, 10:52 AM

I think its odd that a high voltage like that would cause the excessive power usage you see. But, I hope that fixes it for you.

Xringer · 11-30-10, 11:27 PM

Quote:

Originally Posted by Daox

I think its odd that a high voltage like that would cause the excessive power usage you see. But, I hope that fixes it for you.

Why odd? It's simple.. Simple as pie. P=IE

Increase the voltage (E), or current (I) and you get an increase in P (Power)..

See my ideas about the power supply (above) and it sure seems like P=IE
is going to apply to simple transformer-less AC-to-DC power supplies.

The peak DC voltage is going to depend on the peak AC voltage.
My wild guess is that 250vac * 1.414 is going to provide about 353 VDC
to the FETs driving the motors.

We lost another CFL the other day.. I wonder if it was the high line voltage.?.
The bulb was less than two years old..

Xringer · 12-01-10, 08:56 AM

Made it through the night! Set for 21C with an increase to 22C at 7AM.
It's 8:30AM and the total power used since midnight was 2.78 kWh 0.58 USD.
It wasn't too cold over night. Average temp during that time was 46.5 °F

That seems a bit low.

Daox · 12-01-10, 09:50 AM

If anything, I'd think the relatively small increase in AC voltage would translate into a relatively small increase in power consumption, not the huge jumps that you are seeing.

Glad to see it working smoothly again though. That is abnormally high voltages. If anything, at my house I see maybe 1V over/under nominal.

Xringer · 12-01-10, 02:16 PM

Yeah, it's kinda strange. But, sometimes when transistors get hot they start to saturate and go into thermo-runaway..

My joy was short-lived. Early this morning, a big crew of NStar guys came and replaced the service cable between the house & pole..

It's working so good, that now I've got that old high voltage problem again..

Right now, it's 127.9 volts.. (255.8 for the 220).

That Sanyo really needs to be under 253 to work right..
I need a 3KW step-down transformer that will give me 220!

I also noticed my 42" Panasonic plasma TV is rated for 110 to 127.
Maybe my wife will decide not to fall asleep while watching TV..

No wonder the PS on this PC is so warm!!

Xringer · 12-01-10, 04:53 PM

I found a gizmo!

Seven Star 5000 Watt Deluxe Automatic Voltage Regulator, Voltage Converter Transformer (CE Mark), 110220Volts.com,

"In addition to converting 220/230/240 volts to 110/120 volts and visa versa, these voltage regulator transformers will stabilize either 120 volts or 220 volts.
What that means is they will provide stabilized 120 volts when the input is 120 as well as providing a constant stabilized 220 volts when the input is 220/230/240 volts. The input parameters for stabilization (regulation) of power are 80 volts - 140 volts and 120 volts - 240 volts. The output is stabilized to either 110 volts or 220 volts +/- 4%."

It's a $198 gamble? What do you guys think??

Daox · 12-01-10, 05:06 PM

I wonder what the efficiency hit is?

RobertSmalls · 12-01-10, 05:57 PM

It's the power company's job to provide you with good quality power that meets the requirements of your appliances. If they're not doing an adequate job, get on their case!

However, if your heat pump says it can take 258VAC, then it can take 258V without any issues. It can probably take 270V or more, but that's akin to overclocking.

Higher voltage means higher compressor RPM and higher instantaneous power draw, but since the compressor provides cooling commensurately faster, I really don't see how it could have any impact on your average power draw.

Xringer · 12-01-10, 06:38 PM

Wouldn't it be a great world if everybody actually did their jobs..
I am on their case. I just sent another email to NStar Customer Service.

I think their main problem is, they are always on the defensive.
Always explaining why it's not their fault, or that nothing can be done etc.
They seem to look at the customers as the enemy..
We shall see if the get back to me by Friday. If not, I'll place another service call.

~~
I wish it could take 258VAC, but the spec is 187 to 253 volts..

Once it gets up over 253, the power has to be carefully watched.
Once the power gets up around 2.5kW, the rate of increase gets faster.
It can jump up another 500w in a matter of 12 seconds..
Over 3kW and something is going to pop.

My alarm only works in 1kW increments, so I hear beeps when it hits 2kW.
The display update is every 6 seconds.
If I see it's moving rapidly towards 3kW, I back off the temperature request.
Wait a while and try again. It's a PITA when the line voltage is too high.

"Higher voltage means higher compressor RPM and higher instantaneous power draw, but since the compressor provides cooling commensurately faster, I really don't see how it could have any impact on your average power draw. "

It's not the average power draw that worries me.
It's the quick increase to over 2,490 watts that scares me.

Last December the power shot up one cold morning, and RPMs went into Turbo mode, blowing a little pin-hole in a copper tube above the compressor.
It took months to get a replacement unit.
I figured it was bad firmware, but it's really just the design..
The compressor motor controller board, thinks that all voltage is a warm and gentle 220..
Seems like they forgot to put in a top-speed limit subroutine.
I can hear the programmer now, "We never expected it to see more than 253 volts"..

11-30-10, 10:52 AM	#12
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	I think its odd that a high voltage like that would cause the excessive power usage you see. But, I hope that fixes it for you. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

12-01-10, 09:50 AM	#15
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	If anything, I'd think the relatively small increase in AC voltage would translate into a relatively small increase in power consumption, not the huge jumps that you are seeing. Glad to see it working smoothly again though. That is abnormally high voltages. If anything, at my house I see maybe 1V over/under nominal. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

12-01-10, 05:06 PM	#18
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	I wonder what the efficiency hit is? __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

11-30-10, 10:23 AM	#11
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	This morning, I saw 128vac with peaks up to 129vac (258vac on the 220 line).. I called the NStar service line and the truck came out. He drove around measured 127 (254) for a few miles around here.. Woburn, Burlington & Lexington on the same section of grid. Not much they can do I guess. The 'engineers' told him to take out some capacitors on our local transformer. Now we are getting 125.. 250.. Under the Sanyo 253 spec!! Doing some testing now.. Need to heat up this cool house!

12-01-10, 08:56 AM	#14
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Made it through the night! Set for 21C with an increase to 22C at 7AM. It's 8:30AM and the total power used since midnight was 2.78 kWh 0.58 USD. It wasn't too cold over night. Average temp during that time was 46.5 °F That seems a bit low.

12-01-10, 02:16 PM	#16
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Yeah, it's kinda strange. But, sometimes when transistors get hot they start to saturate and go into thermo-runaway.. My joy was short-lived. Early this morning, a big crew of NStar guys came and replaced the service cable between the house & pole.. It's working so good, that now I've got that old high voltage problem again.. Right now, it's 127.9 volts.. (255.8 for the 220). That Sanyo really needs to be under 253 to work right.. I need a 3KW step-down transformer that will give me 220! I also noticed my 42" Panasonic plasma TV is rated for 110 to 127. Maybe my wife will decide not to fall asleep while watching TV.. No wonder the PS on this PC is so warm!!

12-01-10, 04:53 PM	#17
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	I found a gizmo! Seven Star 5000 Watt Deluxe Automatic Voltage Regulator, Voltage Converter Transformer (CE Mark), 110220Volts.com, "In addition to converting 220/230/240 volts to 110/120 volts and visa versa, these voltage regulator transformers will stabilize either 120 volts or 220 volts. What that means is they will provide stabilized 120 volts when the input is 120 as well as providing a constant stabilized 220 volts when the input is 220/230/240 volts. The input parameters for stabilization (regulation) of power are 80 volts - 140 volts and 120 volts - 240 volts. The output is stabilized to either 110 volts or 220 volts +/- 4%." It's a $198 gamble? What do you guys think??

12-01-10, 05:57 PM	#19
RobertSmalls Journeyman EcoRenovator Join Date: May 2009 Location: Buffalo, NY Posts: 344 Thanks: 3 Thanked 17 Times in 15 Posts	It's the power company's job to provide you with good quality power that meets the requirements of your appliances. If they're not doing an adequate job, get on their case! However, if your heat pump says it can take 258VAC, then it can take 258V without any issues. It can probably take 270V or more, but that's akin to overclocking. Higher voltage means higher compressor RPM and higher instantaneous power draw, but since the compressor provides cooling commensurately faster, I really don't see how it could have any impact on your average power draw.

12-01-10, 06:38 PM	#20
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Wouldn't it be a great world if everybody actually did their jobs.. I am on their case. I just sent another email to NStar Customer Service. I think their main problem is, they are always on the defensive. Always explaining why it's not their fault, or that nothing can be done etc. They seem to look at the customers as the enemy.. We shall see if the get back to me by Friday. If not, I'll place another service call. ~~ I wish it could take 258VAC, but the spec is 187 to 253 volts.. Once it gets up over 253, the power has to be carefully watched. Once the power gets up around 2.5kW, the rate of increase gets faster. It can jump up another 500w in a matter of 12 seconds.. Over 3kW and something is going to pop. My alarm only works in 1kW increments, so I hear beeps when it hits 2kW. The display update is every 6 seconds. If I see it's moving rapidly towards 3kW, I back off the temperature request. Wait a while and try again. It's a PITA when the line voltage is too high. "Higher voltage means higher compressor RPM and higher instantaneous power draw, but since the compressor provides cooling commensurately faster, I really don't see how it could have any impact on your average power draw. " It's not the *average power draw* that worries me. It's the quick increase to over 2,490 watts that scares me. Last December the power shot up one cold morning, and RPMs went into Turbo mode, blowing a little pin-hole in a copper tube above the compressor. It took months to get a replacement unit. I figured it was bad firmware, but it's really just the design.. The compressor motor controller board, thinks that all voltage is a warm and gentle 220.. Seems like they forgot to put in a top-speed limit subroutine. I can hear the programmer now, "We never expected it to see more than 253 volts"..