MR ETOS IM - Page 246

7 Operation
Maschinenfabrik Reinhausen GmbH 2019246 5163667/06 ENETOS
®
IM
The device uses the following limit values in accordance with your selection:
Option Calculation method Limit values
K θ
h
θ
o
L
Medium power
(S < 100 MVA)
IEC 60076-7 1.8 160 °C 115 °C No limit
IEEE Std C57.91 2.0 180 °C 110 °C
High power
(S > 100 MVA)
IEC 60076-7 1.5 160 °C 115 °C
IEEE Std C57.91 2.0 180 °C 110 °C
Customer-specific IEC 60076-7 Freely configurable
IEEE Std C57.91
Table64: Limit values for short-term overload
K = load factor
θ
h
= hot-spot temperature
θ
o
= top-oil temperature
L = loss-of-life per day in %
Option Calculation method Limit values
K θ
h
θ
o
L
Medium power
(S < 100 MVA)
IEC 60076-7 1.5 140 °C 115 °C 5%
IEEE Std C57.91 2.0 140 °C 110 °C
High power
(S > 100 MVA)
IEC 60076-7 1.3 140 °C 115 °C
IEEE Std C57.91 2.0 140 °C 110 °C
Customer-specific IEC 60076-7 Freely configurable
IEEE Std C57.91
Table65: Limit values for long-term overload
K = load factor
θ
h
= hot-spot temperature
θ
o
= top-oil temperature
L = loss-of-life per day in %
Note the following limitations for the freely configurable limit values:
θ
h
: min. 140 °C (K > 1), max. 180 °C (risk of bubbling)
θ
o
: min. 110 °C (K > 1), max. 120 °C (should be less than the hot-spot tem-
perature)
To select the used limits, proceed as follows:
1. Go to Settings > Parameters > Overload > Used limits.
2. Select the desired option.
3. Press the Accept button to save the modified parameter.