External Soft Start Resistor - Control Techniques Unidrive Installation Manual

3. Check that the chosen resistor can tolerate the overload
Use the maximum time tripping curve to determine the time that corresponds to a factor
(F) of 7.3
From the maximum time tripping curve you get a time of approximately 10 seconds for a
factor (F) of 7.3.
Check that the braking resistor can tolerate 9.2A for 10 seconds.
5.4

External soft start resistor

Table 5-6 Resistor values
Drive
SP1202 to SP1204
SP2201 to SP2203
SP3201 to SP3202
SP4201 to SP4203
SP1401 to SP1406
SP2401 to SP2404
SP3401 to SP3403
SP4401 to SP4403
SP5401 to SP5402
SP6401 to SP6402
SPMA1401 to SPMA1402
SPMD1401 to SPMD1404
SP3501 to SP3507
SP5601 to SP5602
SP6601 to SP6602
SPMA1601 to SPMA1602
SPMD1601 to SPMD1604
5.4.1 External soft start resistor protection
To protect the soft start resistor from becoming damaged in a failure situation a suitable
fuse needs to be fitted in series with the resistor. The fuse must meet the specification
as detailed below.
Table 5-7 Fuse values
Drive voltage rating
(V)
200
400/575/690
Alternative fuse types.
An alternative to the fuses recommended in Table 5-7 can be used providing the fuse
time vs current characteristic lies between the curves shown in the graphs below and
the voltage rating is as per the value shown in Table 5-7.
Unidrive SP Low Voltage DC Installation Guide
Issue Number: 1
Rs Power
rating
(Ω) (W)
48 148
96 296
N/A N/A
96 296
F4 current F4 DC voltage
rating rating
(A) (V)
1 500
1 1000
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Energy Resistor
rating part
(J) number
N/A
1700 1270-2483
N/A
3400 1270-2483 2x1270-2483 in series
N/A N/A
3400 1270-2483 2x1270-2483 in series
Recommended Fuse
type
(Ferraz)
ATM
A 120X
Resistor
combination
1270-2483
N/A
Alternative fuse
type
As set out below
As set out below
37