The standard measurement on a phase shifting transformers shall be from input terminal to output
terminal on each phase and from the neutral of the shunt winding to the output terminal on each phase,
each on neutral tap and on each extreme tap, a total of 18 measurements. If the phase shifting transformer
is of the two-core type that has external interconnections that can be removed on site, then it shall be
treated as two separate transformers.
Series reactors shall be measured from input terminal to output terminal on each phase, a total of three
measurements for a three-phase reactor. Shunt reactors shall be treated as a star winding on a transform-
er, a total of three measurements for a three-phase reactor without taps and six for a reactor with taps.
Sample connections
IEC and ANSI/IEEE Alternative ANSI/IEEE
End-to-End open Open Circuit Self Admittance (oC)
End-to-End Short-Circuit Short Circuit Self Admittance (SC)
Capacitive Inter-Winding (CIW) Inter-Winding (IW)
Inductive Inter-Winding (IIW) Transfer Admittance (TA)
IEC and ANSI/IEEE Example IEC Example ANSI/IEEE
End-to-End open 1u-1n [open] H1-H0 [open]
End-to-End Short- Circuit 1u-1n [short] H1-H0 [short]
Capacitive Inter- Winding (CIW) 1u-2u [CIW] H1-X1 [IW]
Inductive Inter- Winding (IIW) 1u-2u [IIW, GND
1n, 2n]
H1-X1 [TA, GND H0,X0]
1. In the “End-to-End” (open Circuit Self Admittance, oC) the signal is applied to one end of each winding
in turn, and the transmitted signal is measured at the other end. The low frequency range of this test is
basically a low voltage measurement of the voltage dependent single-phase excitation current.
2. The “End-to-End Short-Circuit (Short Circuit Self Admittance, SC) is measured as the “End-to-End open”
measurement but with one or more windings shorted. The low-frequency range of this test is basically a
low voltage measurement of the single-phase impedance.
Appendix
60 FRAX-series www.megger.com
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