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Appendix B—Protection
S811+ Soft Starter
MN03900001E—November 2012
55
Appendix B—Protection
Thermal Overload
The S811+ Soft Starter features an electronic motor overload
protection feature. This is intended to protect the motor and
power wiring against overheating caused by excessive
current for extended periods of time.
Note: Short circuit protection must be applied on the
line side of the soft starter.
Enter the motor full load current rating, using the
Mtr
Nameplate FLA
parameter in the Soft Start Config Menu to
program the trip current. It is programmable from 32–100%
of the unit’s rated current.
Overload—Adjustment Range—Inline Connected
Overload—Adjustment Range—Inside-the-Delta
Connected
Note:
Mtr Nameplate FLA
parameter is adjustable to any
point within its range.
The thermal overload is designed to protect the motor from
overheating caused by excessive current. If the motor is
overloaded, the current drawn rises and heats the motor. The
FLA sets the trip threshold and the trip class (5 to 30) is set
with the
Ovrld Trip Class
parameter.
If the device trips on a thermal overload, an internal timer is
started which inhibits a reset for three minutes. After this
timer expires, the device may be reset and the thermal fault
is cleared. At this point another internal timer is started, this
timer is 26 x 3 or 48 minutes. If another trip occurs before
this timer expires, the reset inhibit time is increased to
6 minutes.
Catalog
Number
Min
Max
Default
Notes
S811+N37…
11
37
11
Motor FLA parameter
must be set to motor
nameplate FLA to achieve
proper overload
protection
S811+N66…
20
66
20
S811+R10…
32
105
32
S811+R13…
42
135
42
S811+T18…
56
180
56
S811+T24…
75
240
75
S811+T30…
95
304
95
S811+V36…
112
360
112
S811+V42…
131
420
131
S811+V50…
156
500
156
S811+V65…
203
650
203
S811+V72…
225
720
225
S811+V85…
265
850
265
S811+V10…
312
1000
312
Catalog
Number
Min
Max
Default
Notes
S811+N37…
19
65
19
Motor FLA parameter
must be set to motor
nameplate FLA to achieve
proper overload
protection
S811+N66…
35
114
35
S811+R10…
55
182
55
S811+R13…
73
234
73
S811+T18…
97
311
97
S811+T24…
130
415
130
S811+T30…
164
526
164
S811+V36…
193
623
193
S811+V42…
227
727
227
S811+V50…
270
865
270
S811+V65…
352
1125
352
S811+V72…
389
1246
389
S811+V85…
458
1471
458
S811+V10…
539
1732
539