Measurement Setup; Connecting Test Cables To Transformer Terminals - Raytech mini-ATOS Instruction Manual

5 Measurement Setup

5.1 Connecting Test Cables to Transformer Terminals

This part explains the setup measurement for almost all possible measurements of a power
transformer.
Connect the mini-ATOS to the transformer under test with the labelled test leads using the
connection guide in Table 3 and Table 4.
When you want to perform a measurement in which tertiary winding is involved (e.g., Turns ratio
between primary and tertiary), you have to connect the mini-ATOS X Cables to the tertiary side.
Because of safety, take care when you perform tests between secondary and tertiary. The voltage
may transform to a very dangerous level at the primary side during the measurements. Always
keep distance and never touch the test object.
Check the nameplate information of the transformer. If the nameplate is missing it is still possible to
test the transformer by a trial-and-error method. The mini-ATOS test set is designed to detect
errors in transformer hook-ups. Contact Raytech Service & Support department if you need
assistance.
WARNING!
Take care when you test between secondary and tertiary! The voltage
may transform to a very dangerous level at the primary side during the
measurements. Always keep distance and never touch the test object!
Table 3: Test cables connection guide for a Single (1) phase transformer or auto-transformer
Voltage Level
Primary
Secondary
Tertiary
1
Dot can be a letter. For example: 1U1
90297-0.22 Instruction Manual mini-ATOS
mini-ATOS
Test Cable
Label
H1
H2
X1
X2
X1
X2
Transformer Marking Standard
IEEE IEC
1
H1 1.1
H2 1.2
X1 2.1
X2 2.2
Y1 3.1
Y2 3.2
BS
U1 A1
U2 A2
u1 a1
u2 a2
3U1 3A1
3U2 3A2
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