WEG SRW 01, User Manual

Page: 95 / 148

Parameterization
SRW 01 | 5-49
5
NOTE!
The thermal memory, in case of switching off, is not enabled when the cooling time is being used.
If the Cooling Time is being executed, the parameter P007 bit 4 - Relay Status 2 (binary) will indicate the value 1.
Motor
on
(a)
(b)
(c)
Off
Without
cooling time
With
cooling time
Cooling time
t
t
t
Trip level
Trip level
Figure 5.26: (a) to (c) Overload protection with and without cooling time
5.7.14 Overload Parameterization
5.7.14.1 Tripping Class Programming Suggestion
1. Determine the correct starting time.
2. Find the average current during the starting time. An average current can be found for any type of starting
control.
E.g.:
Starting an 80 A motor, the starting current is 480 A, dropping to the nominal after 6 s.
480 A / 80 A = 6 x motor In
So: 6 x In @ 6 s.
Use the data found in the previous example (6 x In) and the 6 s time ( Figure 5.23 on page 5-46 in order to find the
minimum tripping class necessary to start the cold motor, as described at the parameter 640.
t(s)
15
10
5
xIn
6 x motor In
0
6 s
Cold
F.S.=1
Figure 5.27: Cold start tripping class verification