Setting Parameters
01/02 AWB8230-1415GB
154
Electronic motor protection
Using an electronically simulated bimetallic strip, the DV6
frequency inverters can provide thermal monitoring of the
connected motor. With PNU b012, you can match the electronic
motor protection to the full load current of the motor. If the values
entered here exceed the rated motor current, the motor cannot be
monitored with this function. In this case, PTC thermistors or
bimetal contacts in the motor windings must be used.
Let us assume you have a DV6-340-11K. The motor full load
current is 23 A. The setting range goes from 4.6 A = 0.2
x
23 A
to 27.6 A = 1.2
x
23 A. Figure 153 shows the tripping characte-
ristic when PNU b012 contains the value 23.
Use PNU b013 to match the overload protection to your load
conditions. You have three options (
a
Fig. 154 to Fig. 156):
• Increased overload protection; value: 00
• Normal overload protection; value: 01 (default)
• Adjustable overload protection; value: 02
Tripping characteristics at increased overload protection
With increased overload protection (PNU b013 = 00), the tripping
current is reduced, for example, by 80 % at 20 Hz (
a
Fig. 154).
Accordingly, the tripping characteristic is offset to smaller current
values (
a
Fig. 157).
Caution!
At low motor speeds, the output of the motor cooling fan
is diminished, and the motor may overheat despite its
overload protection. You should therefore provide protec-
tion with PTC thermistors or bimetal contacts.
Figure 153: Tripping current characteristic at
I
e
= 23 A
Figure 154: Increased overload protection (PNU b013 = 00)
60
0
26.7 A
116 %
34.5 A
150 %
46 A
200 %
0.5
[s]
t
I
100
80
60
5
20
60
f
[%]
[Hz]
I
Figure 155: Normal overload protection (PNU b013 = 01)
Figure 156: Adjustable overload protection (PNU b013 = 02)
Figure 157: Tripping characteristic for increased overload protection at
20 Hz and
I
e
= 23 A
100
80
90
5
2.5
60
f
[%]
[Hz]
I
PNU b020
PNU b018
PNU b016
PNU b015 b017
b019
A004
I
f
60
0
21.3 A
92.8 %
27.6 A
120 %
36.8 A
160 %
0.5
[s]
t
I
For Moeller Electric Sales and Support call KMparts.com (866) 595-9616
