Atec Megger-550005 - Manual

Single-phase, Hand-cranked TTR
®
Transformer Turns Ratio Test Set
n Used for testing single phase power and
distribution transformers
n Design based on precision bridge
measuring technique
n Unmatched accuracy (±0.1%) in a
portable design
DESCRIPTION
The Single-phase TTR ® Transformer Turns Ratio Test Set
measures the turns ratio and exciting current of windings
in power, potential and current transformers. Deviations
in turns ratio readings indicate problems in one or both
windings or the magnetic core circuit.
The TTR test set aids in identifying:
n Shorted coils
n Open circuits
n Incorrect connections
n Internal faults or tap-changer defects in step regulators as
well as in transformers.
The single-phase, hand-cranked model measures highly
sensitive turns ratios of up to 129.99:1 with accuracy of
±0.1%. An optional auxilary transformer extends the ratio
range to 329.99:1.
The TTR set operates on the principle that the voltage ratio
of the transformer at no load is practically equal to the true
turns ratio.
The major source of error in a transformer is a primary
impedance drop due to magnetizing current, which is kept
to a minimum by excitation at a fraction of rated voltage.
By employing a design that meets both of these conditions
along with the use of a null balance system, the turns ratio
of a transformer can be determined accurately.
When measuring the turns ratio of distribution and power
transformers, the accuracy is well within 0.1%.
APPLICATIONS
The single phase model is primarily used for testing single-
phase power and distribution transformers, for low-ratio
readings up to 129.99:1, or up to 329.99:1 with an auxiliary
transformer. It can be used to test three-phase transformers
by connecting and testing each phase separately.
FEATURES AND BENEFITS
n Provides unmatched accuracy (±0.1%) in a portable de-
sign.
n Packaged in a rugged, compact case.
n Measures highly sensitive turn ratios up to 129.99:1. An
optional auxiliary transformer extends this ratio range to
329.99:1.
SPECIFICATIONS
Output
8 V, 50/60 Hz
Metering
Four decade dials
Turns Ratio Range
0.001 to 129.999
Exciting Current
0 to 1 A (divide by 5 switch for increased resolution)
Accuracy
±0.1%
Dimensions
7.5 H x 14 W x 12 D in. (189 H x 353 W x 302 D mm)
Weight
16 lb (7.3 kg)
Single-phase, Hand-cranked TTR ®
Transformer Turns Ratio Test Set