GE C70 Instruction Manual page 494

CONTROL ELEMENTS
The reset time of the thermal overload protection element is also time delayed using following formula:
where
τ = thermal protection trip time constant
rst
T = a minimum reset time setting
min
5
The thermal overload protection element estimates accumulated thermal energy E using the following equations
calculated each power cycle. When current is greater than the pickup level, I
thermal energy:
5-290
Figure 5-159: IEC 255-8 sample operate and reset curves
C70 CAPACITOR BANK PROTECTION AND CONTROL SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
> k × I , element starts increasing the
n B
Eq. 5-25
Eq. 5-26