Power Factor for AC Pumps

[mark]

is your measurement equipment accurate?

[sphelps]

Originally Posted by mark

is your measurement equipment accurate?

Seems to be. Amps matches another measurement device and while I haven't verified the wattage meter portion of it, it matches other device ratings so I assume its accurate. Either way it's unlikely the wattage used is much higher and if its lower the power factor only decreases more. So unless everything is way off the accuracy isn't that important here.

[mrhasan]

This is what I got from Enmax:

Good morning Raied,

Thank you for contacting ENMAX. My name is Nancy and I appreciate the opportunity to respond to your billing inquiry.

Please accept our apologies for the delay in response. We have been experiencing higher than normal volumes which have impacted our service levels.

Raied, ENMAX meters measure wattage usage.

Should you have any further questions or concerns, please do not hesitate to reply to this email and I will be happy to assist you. Alternatively, you may contact our Customer Care Centre at 310-2010 (Toll Free in Alberta) Monday to Friday 8:00 am to 8:00 pm and Saturday 8:00 am to 4:30 pm.

Thank you for granting ENMAX the opportunity to be of service for you.

Yours truly,


Nancy C.
Customer Correspondence Team
ENMAX and City Utilities

[sphelps]

Yeah she gave me a similar response today as well...

Good afternoon Steven,

Thank you for contacting ENMAX. My name is Nancy and I appreciate the opportunity to respond to your inquiry.

Your ENMAX electric meter measures the amount of power being utilized by your residence.

I did find an article online which may be of interest to you: http://lifeislikethat.com/?p=847.

Steven, should you have any further questions or concerns, please do not hesitate to reply to this email and I will be happy to assist you. Alternatively, you may contact our Customer Care Centre at 310-2010 (Toll Free in Alberta) Monday to Friday 8:00 am to 8:00 pm and Saturday 8:00 am to 4:30 pm.

Thank you for granting ENMAX the opportunity to be of service for you.

Yours truly,


Nancy C.
Customer Correspondence Team
ENMAX and City Utilities

[lastlight]

Originally Posted by Nancy C

Raied, ENMAX meters measure wattage usage

it took her a while to track someone down who knew what the deuce you guys were nattering about.

[sphelps]

Not only that but she really didn't answer the question at all, honestly I think she has no idea what we're talking about. This is the inquiry I sent:

Hello,

As a current customer I'm investigating some techniques for energy saving in my home and I have question relating to power factors and whether a typical residential meter measures apparent power or real power.
For example if I have a load such as pump that has a power factor of 0.5 the current in the circuit will be twice that of what the actual device is using, if the measured current is 5A then the apparent power is 575W on a 115V circuit while the real power used by the device is 288W.
The question I have is does a residential meter measure and bill for real power or apparent power? Is it worth investing in new devices with higher power factors if the goal is reduce electricity cost?

Judging by the response it's pretty clear she has no idea what we're on about and relied on google to quickly find an article that somewhat discusses power factor.

[mrhasan]

Exactly! Come on we know that the usage is based on the wattage meter but the question generally was how/what power does it read. Oh well

[Delphinus]

I'm late to this party, holy moly my head is swimming after reading it from beginning to end. Anyhow, I always thought your billing was based, more or less, on the "loss of potential". I haven't seen that term thrown about in here so now it's in there.

And electrons. I'm pretty sure electricity has something to do with electrons.

And Shaw has little robots that live in your house's wires.

Word.

[StirCrazy]

Originally Posted by sphelps

Ok now we're getting somewhere. My assumption is I'm getting billed in kWh which would include PFs so if my pump is using 82W I'm paying to 82W and not 212W. While the pump is pulling 1.8A it's not using it all, essentially most of it is going back to the grid so to speak. So it's not actually being used, hence the PF related to how effective not efficient. It would certainly be very valuable information for if you could confirm this.

nope this is not how it works
here is a simple explanation of PF I found

"Power factor is the percent of electrical power that does work. Resistive loads, such as lights and heater elements, always have unity (1.0) power factor; all power is used for work. Motors, because they are essentially large inductors, lag current and cause power factor issues. A motor with a .85 power factor uses 85 percent of the power for work. 15 percent is wasted.

For example, a 480VAC, 10HP motor with a 1.0 power factor uses 10.6 amps to run at 10HP. Lowering the power factor to .8 requires the motor to consume 13.2 amps to produce that same 10 HP."

I read up on this years and years ago and can talk about it all day (well maybe not all day) but it is hard to sit and type it out, hence the simple explanation I found. we used to be realy concerned with PF with lights to get the efficiency.


you if you have a pump that is rated at 120 watts but has a power factor of .6 in reality it will use 200 watts to do the work. the extra 80watts are lost through ineficient circuts, heat, ect... so when the power company bills you you are billed for the 200 watts. this is why the hydro companies have rebates for big business to upgrade to high PF equipment, it lowers the demand on the grid.

Steve

[mrhasan]

Originally Posted by StirCrazy

nope this is not how it works
here is a simple explanation of PF I found

"Power factor is the percent of electrical power that does work. Resistive loads, such as lights and heater elements, always have unity (1.0) power factor; all power is used for work. Motors, because they are essentially large inductors, lag current and cause power factor issues. A motor with a .85 power factor uses 85 percent of the power for work. 15 percent is wasted.

For example, a 480VAC, 10HP motor with a 1.0 power factor uses 10.6 amps to run at 10HP. Lowering the power factor to .8 requires the motor to consume 13.2 amps to produce that same 10 HP."

I read up on this years and years ago and can talk about it all day (well maybe not all day) but it is hard to sit and type it out, hence the simple explanation I found. we used to be realy concerned with PF with lights to get the efficiency.


you if you have a pump that is rated at 120 watts but has a power factor of .6 in reality it will use 200 watts to do the work. the extra 80watts are lost through ineficient circuts, heat, ect... so when the power company bills you you are billed for the 200 watts. this is why the hydro companies have rebates for big business to upgrade to high PF equipment, it lowers the demand on the grid.

Steve

Not again!!!

That's what I thought but apparently, the meters in our houses only counts the amount of power used (consumed) by the devices and the industries, in return, are charged PF penalties.