ABB Relion REC670, Applications Manual

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17.10.3 Setting guidelines
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The settings tAlarm and tWarning are user settable limits defined in hours. The
achievable resolution of the settings is 0.1 hours (6 minutes).
tAlarm and tWarning are independent settings, that is, there is no check
if tAlarm > tWarning .
The limit for the overflow supervision is fixed at 99999.9 hours.
The setting tAddToTime is a user settable time parameter in hours.
17.11 Estimation of transformer insulation life LOLSPTR
(26/49HS)
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GUID-A3D72F4B-9567-4DF0-867A-9F657A7E9291 v1
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Estimation of transformer winding
insulation life
LOLSPTR
3Ihp>T
26/49HS
17.11.1 Application
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A typical power transformer is composed of:
• Laminated steel core with copper or aluminium windings
• Solid refined paper insulation
• Highly refined mineral oil as insulating and cooling medium for the entire
transformer
The oil is cooled by a separate cooling system using air or water. The core, windings
and insulation have specific thermal capabilities.
Losses in the winding and core can cause temperature rises in the transformer, which is
transferred to the insulating oil. Failure to limit these temperature rises to the thermal
capability of the insulation and core materials can cause premature failure of the
transformer.
A transformer is rated at the power output. It can continuously deliver at rated voltage
and frequency without exceeding the specified temperature limit. This temperature rise
is based on thermal limitations of the core, winding and insulation. Therefore,
1MRK 511 401-UUS A
Section 17
Monitoring
Bay control REC670 2.2 ANSI 545
Application manual