High-Capacitance Cables - Control Techniques Commander SE Advanced User's Manual

4.10.3 SE Inrush resistor
Drive
SE11200025
SE11200037
SE11200055
SE11200075
SE2D200075
SE2D200110
SE2D200150
SE2D200220
SE23200400
SE23400075
SE23400110
SE23400150
SE23400220
SE23400300
SE23400400
*Commander SE size 5 uses a resistor as its inrush current limiting resistor. Its value remains constant as the temperature
increases.
NOTE
The Commander SE sizes 1 to 4 use surge guards as its inrush current limiting resistors. The ohmic values are
o
given at 25 C. This ohmic value reduces as the surge guards temperature increases.
4.11

High-capacitance cables

Most cables have an insulating jacket between the cores and armour or shield; these cables have low capacitance and are
recommended. Cables that do not have an insulating jacket tend to have high capacitance; if a cable of this type is used, the
maximum cable length is half that quoted in the table. The drawing below shows how to identify the two types.
Figure 4-10 Cable construction influencing the capacitance.
Normal capacitance
Shield or armour
separated from the cores
Maximum motor cable lengths
The capacitive loading of the drive by the motor cable means that the cable length limits shown in the table must be
observed. Failure to do so can result in spurious OI.AC tripping of the drive. If longer cable lengths are required, consult your
local Drive Centre or distributor.
The capacitance of the cable used for the maximum cable lengths and EMC testing on Commander SE was measured at
412pF/m when using method 1 and 130F/m when using method 2, as below.
Method 1
By connecting the 3 phases together as one node and connecting the screen and earth (if any) as the other node and
measuring the capacitance between these two points.
130
Inrush resistor
Drive
o
Ω at 25
C
10 SE33200550
10 SE33200750
10 SE33400550
10 SE33400750
20 SE43401100
20 SE43401500
20 SE43401850
30 SE53402200
30 SE53403000
20 SE53403700
20
20
20
30
30
High capacitance
Shield or armour close
to the cores
412pF
Inrush resistor
o
Ω at 25
C
30
30
30
30
30
30
30
22*
22*
22*
Commander SE Advanced User Guide
Issue Number: 4