Danfoss TI 180 E, Manual

Page: 7 / 32

DKACT.PS.C20.A1.6D
7
Example 2
I
e
= 8.7 A
Motor cable looped four times (see fig. 4) =
4
×
8.7 A = 34.8 A. Setting 35 A.
Slide switches 4 and 5 moved to right
Contact 4 = 5 A
Contact 5 = 10 A
Basic value = 20 A
I
e
= 35 A
Star-delta starting
With star-delta starting, setting must be in
accordance with the phase current in delta
operation and motor protection relay TI 180 E
must be connected to the phase leads (fig. 9).
Rated operating current I
e
must therefore be
multiplied by the factor 0.58 (1:
√
_
3).
With looped connection also multiply by the
number of loops: I
e
×
0.58
×
no. of loops.
Setting l
e
using overcurrent indication of
unit
If the rated motor operating current is not
known, set in accordance with the actual
operating current: with motor running under full
load reduce the current setting on TI 180 E (fig.
7, L) until the overcurrent indicator flashes (fig.
7, G). The set value corresponds to 91% of the
operating current. If this value is now increased
by 10% = (91%+9,1%=100%) the unit is set at
the rated motor operating current I
e
.
Example, fig. 10:
Indication (flashing) at 95 A; I
e
= 95
×
1.1 =
A. Setting: 104 A.
Setting of thermal relay trip time, fig. 7, K
Setting range: 2-30 s in steps of 2 s.
The trip time t
6
×
I
e
at six times rated operating
current I
e
can be determined from the time/
current trip curves, fig. 3, a-f. The permissible
locked rotor time (from cold start) given by the
motor manufacturer must be converted to trip
time t
6
×
I
e
as shown in the interpolation
example, pos. f. This value, rounded down to
the next smaller even number, must be set on
TI 180 E.
Legend for fig. 3:
Ultimate trip values to IEC 947-4
curve a trip curve from cold state with highest
possible trip time setting t
6
×
I
e
= 30 s
curve b trip curve from cold state with normal
trip time setting t
6
×
I
e
= 10 s
curve d trip curve from cold state with lowest
possible trip time setting t
6
×
I
e
= 2 s
curve d trip curve with load I
e
at lowest and
highest possible trip time setting
t
6
×
I
e
= 30 s and 2 s respectively.
curve e trip curve with load I
e
at normal trip
time setting t
6
×
I
e
= 10 s
Interpolation example:
Locked rotor current = 8.5
×
I
e
. Permissible
locked rotor time (from cold state) = 17 s
The nearest trip curve (a) is parallel-displaced
through point (17 s/ 8.5
×
I
e
) and intersects line
6
×
I
e
. This gives 25 s. The slide switches
(fig. 7, K) must therefore be set on 24 s
(fig. 12).
Trip time setting with unknown locked rotor
time
In general, the normal setting for standard
motors t
6
×
I
e
= 10 s can be used if the locked
rotor time is not given.
For special motors, e.g. thermally-critical
submersible pumps, the following procedure
can be used if the locked rotor time is un-
known:
- Start with setting at 2 s
If the thermal relay trips, allow the motor to
cool down and repeat the start attempt with a
4 s setting.
- Continue in the same way setting increased
by 2 s until the motor starts.
Factory-set functions:
- Single-phasing and asymmetry (fig. 7, H)
- Overcurrent indication (flashing red at 1.1
×
I
e
), (fig. 7, G)
- Automatic reset (option)
Commissioning
Connect supply voltage. The output relay pulls
and the green LED (fig. 7, F) signals ready.
Hold pushbutton (Test 6
×
I
e
) down until the
thermal relay trips, after the set time t
6
×
I
e
(fig. 7, K). This opens the output relay and the
red LED (fig. 7, G), thermal overload, will light
up. The green LED will go out at the same
time.
After a cooling time of about 6
×
t
6
×
I
e
(i.e. 60 s
with t
6
×
I
e
= 10 s) press the reset button
(fig. 7, E).
Reset occurs immediately.
Test of thermistor overtemperature protec-
tion
Short-circuit thermistor inputs P1, P2 (fig. 7, D)
for about 0.5 seconds. The output relay will
drop out and the red LED (fig. 7, I) will light up
while the green LED (fig. 7, F) will go out.
Pressing the reset button (fig. 7, E) resets the
motor protection relay immediately.
The motor can now be started.