7PG2113/4/5/6 Commissioning & Maintenance
©2012 Siemens Protection Devices Limited
Chapter 6 Page 52 of 77
2.13
Thermal Overload (49)
Figure 2.13-1 Thermal Overload
Voltage Inputs:
n/a
Current Inputs:
I
L1
(I
A
), I
L2
(I
B
), I
L3
(I
C
),
Disable:
51, 50, 37, 50CBF
Map Pickup LED:
49Alarm
The current can be applied from a 3P balanced supply or phase by phase from a 1P supply. Alternatively the 3
phase current inputs can be connected in series and injected simultaneously from a single 1P source.
The Thermal Overload Setting and Time Constant Setting can be considered together to calculate the operating
time for a particular applied current.
The following table lists operate times for a range of Time Constant Settings for an applied current of 2x the
Thermal Overload setting. Ensure that the thermal rating of the relay is not exceeded during this test.