- 39 -
UMC100-FBP
Universal Motor Controller
UMC100-FBP
Technical Description
FieldBusPlug / Issue: 03.2012
Electronic Overload Protection
The UMC protects three-phase AC motors in compliance with IEC 60947-4-1. The tripping class can be
set to class 5, 10, 20, 30 or 40. The advanced thermal motor model considers both the copper and iron
parts of the motor thus providing the best protection of the motor.
Before an electronic overload trip actually happens, a pre-warning can be generated. During high over-
load situations the prewarning might be raised just a few seconds before the actual trip happens.
The presently used thermal capacity (0...100%) of the motor is available to the user and thus a prediction
of the time to trip for the current load situation. If the motor is switched off the time to trip shows 6553
sec (never trips). If the motor is running the predicted trip time is updated regularly. The smaller the value
the earlier the trip happens.
After an overload trip, the remaining cooling down time (=time to restart) is calculated regularly and also
available to the user. The motor can be restarted if the cooling time is 0 sec.
Block Diagram:
I/I
e
[%]
Thermal
Motor
Model
Cooling
Time
Running
Load >
Restart
Level
Trip
&
Cooling Mode =
Load based
>
T
cooling
&
Cooling Mode =
Time-based
Load
Trip
Load >
Warning
Level
Prewarning
Thermal
Overload
Signal flow of the thermal overload protection
The thermal information of the motor is cyclically stored (thermal memory)
1)
.
After a thermal overload trip the motor must cool down before it can be started again. There are two op-
tions to define the necessary duration of the cooling time.
•
Fixed cooling time: The user has to specify a fixed duration e.g. 15 minutes. After a thermal overload
trip a further motor start is inhibited for that time. The time that has to be adjusted depends on: Motor
size, motor with or without ventilation, the environment temperature etc. Considering these points the
appropriate cooling time can be estimated. Some examples of motor cooling time constants (t.c.) (motor
standstill) can help:
Size
1 kW - 1
pole
5 kW -1 pole 5 kW - 2
pole
20 kW - 2
20 kW - 3
100 kW - 3
c.t.
10 min
15 min
20 min
30 min
40 min
70 min
•
Thermal capacity based cooling: The user specifies to which level (e.g. 60%) the thermal load level must
drop before a motor start is possible again.
1)
If the UMC was switched off while the cooling time was running the UMC restarts the cooling timer with
the remaining cooling time if the power down time was shorter than 20min.
Summary of Contents for UMC100-FBP
Page 1: ...Technical Description Universal Motor Controller UMC100 FBP ...
Page 157: ......