Author Topic: Balanced vs Unbalanced  (Read 3389 times)

cschmelz

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Balanced vs Unbalanced
« on: January 05, 2015, 03:41:23 AM »
I recently moved into a fairly substantial house and the electric bills are a bit troubling, so I want to use my TED to troubleshoot. I have an older 20xxxx series TED5000 with 2 MTUs so I set it up to monitor, for now, the two heat pumps as they are likely the largest source of power suck.

I'm considering moving up to a Ted Pro with 1-2 Spyder setups so I can also monitor concurrently the water heaters x 2 and a few additional circuits (I also use Meters for iOS to manually log the power meter as often as I can to get overall data points)

The Spyder installation manual discusses it's ability to monitor 8 balanced loads vs 4 unbalanced.... So what kind of loads are balanced vs unbalanced?

Heat pumps? Balanced or Unbalanced?
Electric water heaters?
Heat strips for backup heat?

My gut says balanced loads but I can't say for sure.


jfpetesn

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Re: Balanced vs Unbalanced
« Reply #1 on: January 06, 2015, 02:03:38 AM »
Balanced loads are usually 240v motors, water heater I would prob consider it balanced.  Really you can probably use the spyder on 8 circuits, the 220v circuits will use 1 spyder leg and multiply it x2 in the setup.  You might have small inconsistencies in your totals vs using a spyder coil for each 220v leg but close enough in what I do.  If you want to be very accurate then add enough spyders to allow for 2 coils per 220v circuit (heat pumps, dryers, etc) and 1 coil for each 110v circuit. In my home I used one spyder coil for each 220v circuit and 1 coil for the 110v circuits that I chose to monitor.  Not as accurate but close enough to figure out what my big users are.

pfletch101

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Re: Balanced vs Unbalanced
« Reply #2 on: January 06, 2015, 03:23:57 AM »

I'm considering moving up to a Ted Pro with 1-2 Spyder setups so I can also monitor concurrently the water heaters x 2 and a few additional circuits (I also use Meters for iOS to manually log the power meter as often as I can to get overall data points)

The Spyder installation manual discusses it's ability to monitor 8 balanced loads vs 4 unbalanced.... So what kind of loads are balanced vs unbalanced?

Heat pumps? Balanced or Unbalanced?
Electric water heaters?
Heat strips for backup heat?

My gut says balanced loads but I can't say for sure.


I think that you are slightly misconstruing the Spyder Installation Manual. Most loads fed from a domestic 240V double breaker are more or less balanced  - the current flows from one live cable to the other, opposite phase, one. Sometimes the connected equipment may have control circuitry which is connected across 1 live 'side' and neutral, but this will rarely account for a significant amount of power consumption.

The Spyder has eight 'legs'. Each one of these is independent of the others, though their output can be summed for display and storage by the Footprints App. Each leg can monitor a separate wire. For balanced or approximately balanced 240V circuits, you can monitor one of the two live wires and double the measurement to get the circuit's total draw. For a 120V circuit, you monitor the circuit's single live wire. The only time you would need two Spyder 'legs' to monitor a single circuit would be for an unbalanced 240 V circuit, which, as I have noted, would be very unusual. Generally speaking, then, you can assume that one Spyder can monitor and give you meaningful results for the power consumption in 8 separate circuits.

If in doubt about the 'balance' of one of your 240V circuits, you can always monitor both sides for a week or so and see if there is a significant difference.
Peter R. Fletcher
TED Pro Home - main MTUs monitoring utility and PV Solar feeds; 2 Spyders monitoring selected individual circuits

RussellH

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Re: Balanced vs Unbalanced
« Reply #3 on: January 06, 2015, 09:12:59 PM »
The only time you would need two Spyder 'legs' to monitor a single circuit would be for an unbalanced 240 V circuit, which, as I have noted, would be very unusual.

Not necessarily.  Depending on how the heating elements are controlled, an electric stove could have a significant unbalanced load.  (Hi = heater on 240V.  Medium = heater on 120V.

A washer/dryer combo could have 120V motors, but use 240V for heating. 

I'd say that if a 240V load doesn't have a neutral, then it's balanced.  If it does have a neutral, then it may be unbalanced (but might be close enough for your purposes.)

pfletch101

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Re: Balanced vs Unbalanced
« Reply #4 on: January 07, 2015, 05:53:11 AM »
The only time you would need two Spyder 'legs' to monitor a single circuit would be for an unbalanced 240 V circuit, which, as I have noted, would be very unusual.

Not necessarily.  Depending on how the heating elements are controlled, an electric stove could have a significant unbalanced load.  (Hi = heater on 240V.  Medium = heater on 120V.


Theoretically true, I guess, but I haven't run into one that worked that way.

Quote

A washer/dryer combo could have 120V motors, but use 240V for heating.

 

That certainly is a possibility, though combos are still relatively unusual compared to separates.

Quote

I'd say that if a 240V load doesn't have a neutral, then it's balanced.  If it does have a neutral, then it may be unbalanced (but might be close enough for your purposes.)


No argument about that.
Peter R. Fletcher
TED Pro Home - main MTUs monitoring utility and PV Solar feeds; 2 Spyders monitoring selected individual circuits

RussellH

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Re: Balanced vs Unbalanced
« Reply #5 on: January 07, 2015, 09:30:59 PM »
The only time you would need two Spyder 'legs' to monitor a single circuit would be for an unbalanced 240 V circuit, which, as I have noted, would be very unusual.

Not necessarily.  Depending on how the heating elements are controlled, an electric stove could have a significant unbalanced load.  (Hi = heater on 240V.  Medium = heater on 120V.


Theoretically true, I guess, but I haven't run into one that worked that way.

I've seen two styles of burners:

1) A single coil burner with a dial-type controller.  This uses 240V cycled on/off to get the heat desired.

2) A dual coil burner with a push-button controller.  There's a "hi" coil and a "low" coil.  The pushbuttons select a combination of 0/120/240 to the two coils to get the desired heat.  (A total of 9 combinations possible - counting "off")

Ar_Gir

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Re: Balanced vs Unbalanced
« Reply #6 on: January 27, 2015, 11:55:08 AM »
The only time you would need two Spyder 'legs' to monitor a single circuit would be for an unbalanced 240 V circuit, which, as I have noted, would be very unusual.

Not necessarily.  Depending on how the heating elements are controlled, an electric stove could have a significant unbalanced load.  (Hi = heater on 240V.  Medium = heater on 120V.


Theoretically true, I guess, but I haven't run into one that worked that way.

Quote

A washer/dryer combo could have 120V motors, but use 240V for heating.

 

That certainly is a possibility, though combos are still relatively unusual compared to separates.

Quote

I'd say that if a 240V load doesn't have a neutral, then it's balanced.  If it does have a neutral, then it may be unbalanced (but might be close enough for your purposes.)


No argument about that.

Absolutely agree!