Eq5 ac drive operations manual – HP Anab EQ5 User Manual
Page 107
EQ5 AC Drive Operations Manual
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TECO – Westinghouse Motor Company Main Circuit Voltage, Current & Power Measurements 101
7-3 Main Circuit Voltage, Current, and Power Measurements.
When making main circuit voltage and current measurements, the resulting values depend on the type
of meter used due to the harmonic component included in the voltage and current of the main circuit
power (input) and the output (motor) side of the inverter. When measuring with a meter for
commercial power frequency, use the meters shown in Table 7-3-1.
The power-factor cannot be measured directly using power-factor meters commercially available at
present on the market, which measure the phase difference between voltage and current. When
power-factors must be measured, measure the power, voltage, and current on both the input side and
output side, then calculate the power-factor using the following formula:
[%]
]
[
]
[
]
[
0
0
1
A
t
n
e
r
r
u
C
V
e
g
a
t
l
o
V
3
W
r
e
w
o
P
r
o
t
c
a
f
r
e
w
o
P
Ч
Ч
Ч
=
−
Table 7-3-1 Meters Used for measuring Main Circuit Values
Item
Input (power supply) Side
Output (motor) Side
DC Link
Circuit
Voltage
(P(+) - N(-))
Voltage Current*
Voltage Current
Meter
name
Ammeter
A
R,S,T
Voltmeter
V
R,S,T
Powermeter
W
R,S,T
Ammeter
A
U,V,W
Voltmeter
V
U,V,W
Powermeter
W
U,V,W
DC voltmeter
V
Meter
type
Moving-
iron type
Rectifier
or moving-
iron type
Digital power
meter
Moving-
iron type
Rectifier
type
Digital power
meter
Moving-coil
type
Symbol
Note: When measuring the output voltage using a rectifier type meter, an error may occur.
Use a digital AC power meter to ensure accuracy.
Meter Placement Diagram