Setting Guidelines - ABB RELION RET670 Applications Manual

Section 15
Control
15.4.3
15.4.3.1
790
Wearing of the tap changer contacts
Two counters, ContactLife and NoOfOperations are available within the Tap changer
control and supervision function, 6 binary inputs TCMYLTC or 32 binary inputs
TCLYLTC (84). They can be used as a guide for maintenance of the tap changer
mechanism. The ContactLife counter represents the remaining number of operations
(decremental counter) at rated load.
=
ContactLife ContactLife
n+1
EQUATION1873 V2 EN-US
where n is the number of operations and α is an adjustable setting parameter,
CLFactor, with default value is set to 2. With this default setting an operation at rated
load (current measured on HV-side) decrements the ContactLife counter with 1.
The NoOfOperations counter simply counts the total number of operations
(incremental counter).
Both counters are stored in a non-volatile memory as well as, the times and dates of
their last reset. These dates are stored automatically when the command to reset the
counter is issued. It is therefore necessary to check that the IED internal time is correct
before these counters are reset. The counter value can be reset on the local HMI under
Main menu/Reset/Reset counters/TransformerTapControl(YLTC,84)/TCMYLTC:
1 or TCLYLTC:1/Reset Counter and ResetCLCounter
Both counters and their last reset dates are shown on the local HMI as service values
under Main menu/Test/Function status/Control/TransformerTapControl(YLTC,
84)/TCMYLTC:x/TCLYLTC:x/CLCNT_VALandMain menu/Test/Function status/
Control/TransformerTapControl (YLTC,84)/TCMYLTC:x/TCLYLTC:x/
CNT_VAL

Setting guidelines

TR1ATCC or TR8ATCC general settings
TrfId: The transformer identity is used to identify transformer individuals in a parallel
group. Thus, transformers that can be part of the same parallel group must have unique
identities. Moreover, all transformers that communicate over the same horizontal
communication (GOOSE) must have unique identities.
Xr2: The reactance of the transformer in primary ohms referred to the LV side.
a
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I
load
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÷
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n
I
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rated
1MRK 504 163-UUS A
SEMOD159053-376 v4
(Equation 512)
Transformer protection RET670 2.2 ANSI
Application manual
SEMOD171503-1 v1
SEMOD171501-4 v3