Download Leakage Reactance Interface

M4110
Leakage Reactance Interface
Detect transformer winding distortion easily with
the M4110 Leakage Reactance Interface
Patented* Test Method to detect
Transformer Winding Distortion.
Easy Comparison of Baseline
Data to Future Test Data.
Measurement Comparable to
Factory Nameplate Data
Good Repeatability of Test
Results
Simple to Use
The leakage reactance measurement is a test that is
easy to perform and serves as a reliable indicator of
transformer winding distortion. Winding distortion,
caused by the mechanical forces of an overcurrent
event, can lead to immediate failure. Although a
transformer can remain in service with partially
deformed windings, its reliability is reduced.
Winding distortion is not readily picked up by other
AC field tests and should therefore be included during maintenance testing. The test is also recommended during acceptance testing, to uncover damage incurred during shipment.
If one winding in a transformer is short-circuited,
and test voltage is applied to another winding, the
magnetic flux path includes the space between and
within the windings. Reactance measured under
these conditions is determined by the reluctance of
that space, and is referred to as leakage reactance.
Leakage reactance is sensitive to winding distortion
and insensitive to temperature or presence of contamination. The M4100 instrument, together with
the M4110 Leakage Reactance Interface, performs
the leakage reactance measurement on transformers
of any size and various winding configurations.
The three-phase Leakage Reactance measurement
can be compared to the short-circuit impedance
nameplate value obtained at the factory. Individual
phases can also be tested. The M4110 Leakage
Reactance Interface contains the circuitry necessary
to convert the voltage and current measured during
a Leakage Reactance test on a transformer into a
form that can be measured by the M4100
Instrument. It also contains a variac to obtain the
proper test voltage.
When using this interface, the standard M4000 safety switch and safety strobe are used. The required
current and voltage cables are provided for connection to the transformer, along with the necessary
software.
*U.S. Patent 5,818,245. Australian Patent AU-52 105/93. European Patent Pending
Doble Engineering Company 85 Walnut St. Watertown, MA USA 02472-4037 Tel +1 617.926.4900 Fax +1 617.926.0528
M4100 Instrument and M4110 Leakage Reactance Interface Test Connections
Safety Switch
Safety Strobe
M4100 Low Voltage Lead
M4100 Low Voltage Lead
M4110 Voltage Source
M4110 Voltage sense leads
Black
White
Short-circuiting jumper should be rated
for the current it will carry during the test.
M4110 Specifications
Impedance Measurement:
Inductance:
Range: 0.1 to 700 ohms
Inductance Range
Accuracy
(@ 60 Hz at less than 10% Power Factor)
Resistance:
250 µH to 1.8 H
1% of reading or ± 10 µH
Resistance Range
Accuracy
(greater than 90% Power Factor)
0.1 to 700 ohms
AC Input Requirements:
Source Output Capability:
1% of reading or ± 10 milliohms
120 or 240 V at 10 A (50/60 Hz)
240 V rms Input
0-280 V rms Output Voltage
2.6 kVA Output VA Continuous
Accuracy N.A.
120 V rms Input
Short time overload current (120/240 V input)
0-280 V rms Output Voltage
25 A rms 4-8 minutes before thermostat shuts output off
1.2 kVA Output VA Continous
Physical:
Dimensions
Weight
12”H x 10”D x 13.5”W
35 lbs.
(31 cm H x 25 cm D x 34 cm W)
15.9 kG
For more information, contact: Doble Engineering Company
MRKT-SL-80 rev B
85 Walnut Street
Watertown, MA 02472-9107 USA
T. 617.926.4900
F. 617.926.0528
www.doble.com