Full Product Manual

Document: September1, 2009 Page 5of 10
The %Vd at 8 amps would be
• %Vd= (Vd/Vno-load) x 100
• %Vd= (5/120) x 100
• %Vd= (..0416) x 100
• %Vd= 4.16
It should be noted that the higher the current the large the IR voltage drop and % of
Voltage Drop. To check the accuracy of the UUT at 12amp, 15amp and 20 amps we will
use the impedance as found with the 8 amp load of rZ = 0.625. With this impedance we
can calculate the VD and % VD for any load current.
So for a 12 amp load with a no load voltage of 120V the %VD is :
• Vd= I x R
• Vd= 12 x .625
• Vd=7.5
• %Vd= (Vd/Vno-load) x 100
• %Vd= (7.5/120) x 100
• %Vd= (.0625) x 100
• %Vd= 6.25
STANDARDIZING A BRANCH CIRCUIT
This is the most straightforward way of standardizing a branch circuit for testing the
SureTest™. This procedure should be conducted only by qualified personnel. It is highly
recommended that a license electrician be present to assist with the measurements of the
conductors of the branch circuit being standardize
Recommended equipment:
• Constant Load of 8 to 10 amps at 1500W. It is highly recommended that this
loads be as stable as possible with little drift or error due to temperature
variations.
• High accuracy True RMS voltage meter with accuracy of .25% or better.
• AC Current meter with and accuracy of .5% or better.
• Low resistance switch, or method to move Load from High and Neutral to High
and ground during test
The following measurements should be taking on a dedicated branch circuit if possible. If
there is any change in Line voltage or load on source during test it will have an adverse
effect on the measurement.
For best results AC current should be measured using the series method on the High or
Hot conductor. The voltage and current measurements should be recorded with each step
list below.