16
Instruction Leaflet
I. L. 29-886B
Effective August 2011
Instructions for Digitrip RMS 610 Trip Unit
eaton corporation
www.eaton.com
3.3 Long Delay Time Setting
There are eight (8) available Long Delay Time Settings, as illustrated
in Figure 13, ranging from 2 to 24 seconds . These settings are the
total clearing times in seconds, when the current value equals six
(6) times
I
r
. The (LS) Time-Current Curve applicable for your circuit
breaker gives complete details (see Section 5) .
otee:
N
In addition to the standard Long Delay Protection Element, the Digitrip
RMS 610 Trip Unit also has a Long Time Memory (LTM)function, which serves
to protect load circuits from the effects of repeated overload conditions . If
a breaker is re-closed soon after a Long Delay Trip, and the current again
exceeds the Long Delay Current Setting,
I
r
, the
LTM
automatically reduces
the time to trip, to allow for the fact that the load circuit temperature is
already higher than normal, due to the prior overload condition . Repeated
overload can cause LTM to trip the breaker after a time delay less than the
“Long Delay Time Setting” . When the load current returns to normal, the
LTM
begins to reset; and after about 10 minutes it has reset fully, so that
next Long Delay trip time will again be the "Setting" value . To reset the
LTM
quickly, see Section 4 .4, Item 3 .
Figure 13. Long Delay Time Settings.
3.4 Short Delay Current Setting
There are eight (8) available Short Delay "Pick-up" Current Settings,
as illustrated in Figure 14 . Six settings are in the range from 2
to 6 times
I
r
and the other two settings are "S1" or "S2" times
I
r
(REMEMBER:
I
r
is the Long Delay Current Setting) . The values that
"S1" and "S2" have depend upon the type of circuit breaker, and are
specified both on the rating plug label (see Figure 9) and on the
applicable (LS) Time-Current Curve referenced in Section 5 .
Figure 14. Short Delay Current Settings.
.
,
,
Available Settings
12, 15, 20, 24
I...
Seconds at
6 Times
,
.
. .
.
.
6
x
Long
Time
Delay
Sec.
at 6 x
I
r
I
r
4
(I )
r
Long Delay Setting
2, 4, 7, 10,
. .
S1 and S2
2, 2.5, 3, 4
Available Settings
. .
.
Setting
In Multiples of
Long Delay Setting
Values are Specified on Rating Plug
5, 6, S , S
1
2
I
r
(I )
r
3.5 Short Delay Time Setting
As illustrated in Figure 15, there are two different Short Delay curve
shapes, i .e ., fixed time (flat) and I
2
t response . The shape selected
depends on the type of selective coordination chosen . The I
2
t
response will provide a longer time delay in the low-end of the short
delay current range than will the flat response .
Five flat ( .1, .2, .3, .4, .5 sec .) and three I
2
t ( .1*, .3*, .5* sec .)
response time delay settings are available . The I
2
t response settings
are identified by the suffix asterisk (*) that appears in the setting
viewing window . The I
2
t response is applicable to currents less than
eight (8) times I
r
the Long Delay Setting . For currents greater than 8
times
I
r
the I
2
t response reverts to the flat response .
otee:
N
See also Section 1 .1 .5, Zone Interlocking .
Figure 15. Short Delay Time Settings.
3.6 Instantaneous Current Setting
There are eight (8) available lnstantaneous Current Settings, as illus-
trated in Figure 16 . Six settings are in the range from 2 to 6 times
the rating plug value (I
n
), and the other two settings are "M1" and
"M2" times (I
n
) . The values that "M1" and "M2" have depend upon
the type of circuit breaker, and are specified both on the rating plug
label (see Figure 9), and on the applicable (I) Time-Current Curve ref-
erenced in Section 5 .
Figure 16. Instantaneous Current Settings.
.1*, .3*, .5*
.1, .2, .3, .4, .5,
:
,
Short Delay
Time
Available Settings
Seconds with
:
Flat Response
.......
.
.
.
Shape
Returns
to
Flat
Response at Currents
Higher than
. .
,
.
.-----
“*” In Viewing Window
I
Indicates
Shape
I t
2
8 x
I
r
I t
2
8 x
I
r
Seconds with
I t
2
Shape
Available Settings
:-----
6 X
In Multiples of
Rating Plug
Amperes
M1 and M2 Values are Specified o
n Rating Plug
I
n
Setting Inst.
(I )
n
5, 6, M , M
2, 2.5, 3, 4,
1
2
