Voltech AT360, User Manual

Page: 332 / 470

T
ESTS AND
T
EST
C
ONDITIONS
P
AGE
7-34 V
OLTECH
AT
I
U
SER
M
ANUAL
7.1.8 RLS, RLP – AC R
ESISTANCE
(S
ERIES AND
P
ARALLEL
C
IRCUIT
)
Measurement
Range
Test
Voltage
Test
Frequency
Basic
Accuracy
10
µΩ
 to 10M
Ω
1mV to 5V 20Hz to 3MHz 0.05%
The equivalent AC resistance of a winding may be different to that
measured at DC. The resistive part of the complex winding impedance
will be modified by in phase core losses and skin and proximity effects.
The transformer I
2
R losses will then be different to those calculated
using the DC resistance.
Where Used
The equivalent series or parallel resistance test is used to determine the AC
equivalent resistances of a transformer. As opposed to the DC resistance test,
R, which uses DC voltages, the RLS and RLP tests apply AC voltages at a
specified voltage and frequency.
The measurement of AC resistance at a particular frequency helps to ensure
that the winding has been correctly wound with the correct gauge of wire and
correctly assembled onto the correct type of core material.
Normally, the equivalent resistance test would follow an inductance test on the
same winding. Using the same test conditions for both tests will speed the
execution of the program.
AT Series
Tester
Rp
Ls
Rs
Lp