Figure 3.23 – Rockwell Automation 825 Smart Motor Manager User Manual User Manual
Page 69
Functions 3-36
Publication 825-UM001B-EN-P January 2001
Figure 3.23 Current and Temperature Curves for Warm and Cold Motor Starts and
the Smart Motor Manager Tripping Limits
,
A
Starting current
1
First start (cool)
,
e
Rated current
2
First warm start
ϑ
e
Permissible temperature
3
Second warm start
of the motor in conti-
4
Cold start (after the motor
nuous operation and
has cooled down)
normal tripping limit
t
1
Minimum time before first
of 825-M for continuous
start is possible
operation
(t1 > 10t
6
,
e)
ϑ
1
Motor temperature
t
w
Minimum waiting time
permissible for a short
warm starts (4…60 min.)
time and tripping limit
of 825-M with modified
characteristic for warm start
An attempt to start may be made before the time has elapsed. The Smart Motor Manager will
trip during starting if the thermal capacity available is not sufficient.
ATTENTION
!
The motor manufacturer's instructions must be complied with,
especially regarding the minimum wait between two starts
I
A
I
e
ϑ
1
ϑ
e
t
1
t
w
t
w
t
w
I
ϑ
t
t
1
2
3
4