Hello Text!

Wow, another "Legacy" Thread brought back to life today! [Linked Image]

For the Volt-Amp Load to enter in a Panel Schedule, find the Apparent Power Requirements of the load(s) served. This would equate to:

E×I=VA

Where:
"E" = System's Nomimal / Rated Voltage,

"I" = Listed / Nameplate Full-Load (or Running Load) Amperes at a given System Voltage,

and

"VA" = Rated Load Volt-Amps (or Apparent Power).

The VA Ratings of equipment will be a combination of the True Power (Wattage) "Consumed" by the load, versus the Power Factor (and corresponding Reactive Power, or VARs).

A couple of examples using the 400 Watt Metal Halide Lamp/Ballast Combination are as follows:

System Nominal Voltage: 120 VAC
Lamp: 400 Watt Metal Halide (ANSI M59)

<OL TYPE=A>

[*] Nominal Power Factor Ballast (0.50 P.F.):
Listed input Amperes at 120 VAC = 6.67 Amps,


[*] Corrected Power Factor Ballast (0.8334 P.F.):
Listed input Amperes at 120 VAC = 4.0 Amps,


[*] High Power Factor Ballast (0.909 P.F.):
Listed input Amperes at 120 VAC = 3.667 Amps.
</OL>

For example "A", the Load Volt-Amps will be 800 VA. This is the value to enter in the appropriate cell of the Panel Schedule Database (the 800 Volt-Amps).

For example "B", the Load Volt-Amps will be 480 VA, so in this case the value entered into the appropriate cell will be 480 Volt-Amps.

For example "C", the Load Volt-Amps will be 440 VA, thus in this case, the value of 440 Volt-Amps would be entered into the Schedule's appropriate cell.

(BTW, these examples reflect only one Fixture, or Lamp/Ballast combination. Add VA ratings per number of Fixtures on a given Circuit, then enter that data to the Schedule's cell or cells).

FYI:
Here are the complete figures for "A" through "C" above:

<OL TYPE=A>

[*] True Power (Wattage) = 400 W,
Apparent Power (Volt-Amps) = 800 VA,
Reactive Power (Volt-Amps Reactive = 692.82 VARs


[*] True Power (Wattage) = 400 W,
Apparent Power (Volt-Amps) = 480 VA,
Reactive Power (Volt-Amps Reactive = 265.3 VARs


[*] True Power (Wattage) = 400 W,
Apparent Power (Volt-Amps) = 440 VA,
Reactive Power (Volt-Amps Reactive = 183.3 VARs
</OL>

This should be what you are looking for!

Scott35

Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!