Departure From Reference Setting; Departure From Reference Frequency; Departure From Reference Temperature; High Set Overcurrent Function - Siemens 7SG164 Ohmega 400 Series Manual

8.6 Departure from reference setting

The class index plus an error not exceeding the class index.

8.7 Departure from reference frequency

Over the range of 47 – 52 Hz (50Hz nominal) or 57 – 62 Hz (60Hz nominal), the variations in accuracy are the
class index plus an error not exceeding the class index.

8.8 Departure from reference temperature

The variations in accuracy over the operating temperature range is the class index plus an error not exceeding the
class index.

8.9 High Set Overcurrent Function

Operating Current
≤ ±5% of setting
Reset current
>95% of operating current
Overcurrent Time (OCT)
≤ ±1% or ±10ms (whichever is greater)

8.10 Forward and Reverse Directional Earth Fault Functions

Operating Current
≤ ±5% of setting
Reset Current
>95% of operating current
Definite Time Lag
≤ ±1%
DEF DTL Timers (DEFF, DEFR)
≤ ±1% or ±5ms (whichever is greater)

8.11 Power Swing (PS) Impedance Variation Setting Range

Characteristic or Impedance Variation
≤ ±5% error

8.12 Timing

Figures 1, 2 and 3 shown typical timing curves.

8.13 Fault locator

Accuracy is dependant upon circuit configuration and power flow conditions.

8.14 Thermal Withstand

Continuous and Limited Period Overload
AC Current Inputs
12A
15A
30A
AC Voltage Input –3.5Vn
Short Term Overload
340A
©2011 Siemens Protection Devices Limited
7SG164 Ohmega 400 Series Performance Specification
Continuous
for 10 minutes
for 2 minutes
Continuous
for 1 sec
Chapter 5 Page 8 of 13