HP Extech 380976 - Manual (Page 6)

380976 V3.2 4/11 6
AC Power Measurements
1Φ KW, KVA, KVAR, Power Factor & Phase Angle Measurement
1. Set the rotary switch to the ‘KW/KVA’
position.
2. Insert the test leads to the meter as
follows: Black to ‘COM’ and Red to ‘V’.
3. Connect the black lead to the neutral line.
4. Connect the red lead to the power line
and clamp onto the same lead to which
the red lead is connected.
5. The meter selects the best range
automatically.
6. Select the desired display combination
using the RANGE key. Press RANGE to
scroll through the following combination displays:
ƒ kW and HP (horsepower)
ƒ kW and PF (power factor)
ƒ kW and KVAR (reactive power)
ƒ KVA and phase angle (θ)
ƒ V and A
Note that LEAD and LAG icons are also displayed on the LCD to inform the user that the voltage is
leading or lagging the current with regard to phase.
Note: Allow 2 seconds after each RANGE key press for the meter to update the display.
1 HP = 746 Watts
PF
KW
KVA
=
= cosθ
KVA (Apparent Power) = (V*A) / 1000
KVAR (Reactive Power) = (KVA) (KW) 2 2 − = KVA * sinθ
NOTES
1. The ‘+’ sign printed on the meter must face the power source for best accuracy.
2. If the device under test is a switching mode power supply, the KW, PF, and Phase angle
measurements may not be accurate.