Figure 4-7: Manual/Automatic Switchover - Siemens sirius System Manual

Recovery time
Manual-automatic
Resetting
Tripping characteristics
SIRIUS System Manual
GWA 4NEB 430 0999-02b
Automatic reset
Manual reset
Table 4-6: Recovery time
1) Dependent on the setting range
The following figure shows how to switch between manual and automatic
for the 3RU11 and 3R10 using the example of the 3RU11, frame size S00:
MANUAL
AUTO

Figure 4-7: Manual/automatic switchover

The 3RU11 thermal overload relay can also be reset manually after the
bimetals have cooled down (after approx. 3 to 5 minutes), or it can reset
itself automatically after this time when the AUTO position is set.
The 3RB10 electronic overload relay can be reset at any time by pressing the
RESET button. The recovery time for the automatic reset is 4 minutes.
3RU11
The time-current characteristics show the dependency of the tripping time
from a cold state on the multiple of the set current I
When the relay is at operating temperature, preloaded with 1x I
ping times are reduced to around 25 %. In the case of a single-pole load, the
tripping characteristics lie between the characteristics. In normal operation,
all three bimetal strips of the overload relay must be heated.
The 3RU overload relays are suitable for protecting motors with phase con-
trol.
To protect single-phase or direct current loads, all three main conducting
paths must be connected in series. The minimum tripping current in the
case of a three-pole symmetric load lies between 105 % and 120 % of the
set current.
3RU11, 3RB10, and 3RB12 overload relays
3RU11
1)
3 to 5 min
1)
3 to 5 min
.
e
3RB10
4 min
Immediate
, the trip-
e
4-17