Ratings; Output Circuit And Motor Protection; Table 4-7 Fuse Ratings And Cable Sizes; Table 4-8 Maximum Ac Input Fusing - Emerson Digitax ST User Manual

Safety Product Mechanical
Information information installation
4.6

Ratings

Fuses
The AC supply to the drive must be installed with suitable protection against overload and short-circuits. The following section shows
recommended fuse ratings. Failure to observe this requirement will cause risk of fire.
WARNING

Table 4-7 Fuse ratings and cable sizes

No of
Model input
phases
DST1201 1
DST1202 1
DST1203 1
DST1204 1
DST1201 3
DST1202 3
DST1203 3
DST1204 3
DST1401 3
DST1402 3
DST1403 3
DST1404 3
DST1405 3
Control cable
NOTE
PVC insulated cable should be used.
Installation class (ref: IEC60364-5-52:2001)
B1 - Separate cables in conduit.
B2 - Multicore cable in conduit
C - Multicore cable in free air.
NOTE
Cable sizes are from IEC60364-5-52:2001 table A.52.C with correction
factor for 40°C ambient of 0.87 (from table A52.14) for cable installation
method B2 (multicore cable in conduit).
Cable size may be reduced if a different installation method is used, or if
the ambient temperature is lower.
The recommended cable sizes above are only a guide. The mounting
and grouping of cables affects their current-carrying capacity, in some
cases smaller cables may be acceptable but in other cases a larger
cable is required to avoid excessive temperature or voltage drop. Refer
to local wiring regulations for the correct size of cables.
N
NOTE
The recommended output cable sizes assume that the motor maximum
current matches that of the drive. Where a motor of reduced rating is
used the cable rating may be chosen to match that of the motor. To
ensure that the motor and cable are protected against overload, the
drive must be programmed with the correct motor rated current.
N
NOTE
UL listing is dependent on the use of the correct type of UL-listed fuse,
and applies when symmetrical short-circuit current does not exceed
100kA. See Chapter 14 UL listing information on page 198 for sizing
information.
An MCB (miniature circuit breaker) may be used in place of fuses under
the following conditions:
• The fault-clearing capacity must be sufficient for the installation
2
• The I T rating of the MCB must be less than or equal to that of the fuse
rating listed above.
A fuse or other protection must be included in all live connections to the
AC supply.
24
Electrical Getting Basic
installation started parameters
Typical input Maximum
current continuous input
current
A A
4.0
7.6
9.0
13.4
3.1 3.5
6.4 7.3
8.6 9.4
11.8 13.4
2.6 2.8
4.2 4.3
5.9 6.0
7.9 8.0
9.9 9.9
www.controltechniques.com
Running the SMARTCARD
Optimization
motor Operation
Fuse rating
IEC class
Class CC
gG
6 10
10 10
16 15
16 20
6 10
10 10
16 15
16 20
4 10
6 10
8 10
10 10
12 15
For a parallel DC bus system the maximum AC input fusing is shown in
Table 4-8 below.

Table 4-8 Maximum AC input fusing

Fuse rating
IEC class gG
Model
All
NOTE
Refer to the supplier of your drive for further information regarding DC
bus paralleling.
4.7

Output circuit and motor protection

The output circuit has fast-acting electronic short-circuit protection which
limits the fault current to typically no more than five times the rated
output current, and interrupts the current in approximately 20µs. No
additional short-circuit protection devices are required.
The drive provides overload protection for the motor and its cable. For
this to be effective, Pr 0.46 Motor rated current must be set to suit the
motor.
Pr 0.46 Motor rated current must be set correctly to avoid a
risk of fire in the event of motor overload.
WARNING
There is also provision for the use of a motor thermistor to prevent over-
heating of the motor, e.g. due to loss of cooling.
4.7.1 Motor cable size and maximum lengths
Since capacitance in the motor cable causes loading on the output of the
drive, ensure the cable length does not exceed the values given in Table
4-9.
Use 105°C (221°F) (UL 60/75°C temp rise) PVC-insulated cable with
copper conductors having a suitable voltage rating, for the following
power connections:
Onboard Advanced Technical
PLC parameters Data
Cable size
Input
2
AWG
mm
0.75 16
1 16
2.5 14
2.5 12
0.75 16
1 16
2.5 14
2.5 12
0.75 16
0.75 16
0.75 16
1 16
1.5 14
≥0.5
20
Fuse rating
Input cable size
class CC
A A
mm
20 20 4.0
Digitax ST User Guide
UL listing
Diagnostics
information
Output
2
AWG
mm
0.75 24
0.75 22
0.75 20
0.75 18
0.75 24
0.75 22
0.75 20
0.75 18
0.75 24
0.75 24
0.75 22
0.75 20
0.75 18
2
AWG
12
Issue: 3