![background image](http://html1.mh-extra.com/html/eaton/nrx-digitrip-1150i/nrx-digitrip-1150i_instruction-leaflet_524886034.webp)
Section 10: Frame ratings and rating
plugs
The maximum current the circuit breaker can continuously carry
(In) is stated on the front label. This frame rating also indicates
the largest rating plug that can be installed in that circuit
breaker.
A rating plug value, (I
n
), that is equal to or less than the
maximum continuous current rating may be chosen to be
the basis for the coordination of the protection function of
the circuit breaker without affecting its short-circuit current
capability.
Generally rating plugs are defined per customer breaker
selection upon ordering and are installed in the factory. Field-
installable kits are available as defined in
Table 11
and
Table 12
.
For the Series NRX-NF frame, there are three groupings of
rating plugs available: Group A, Group B, Group C (see
Table
11
). For example, NA800T is for the NRX-NF Frame, Series
NRX-NF frame Group A, 800A Trip. It is important to select the
proper group when choosing another replacement rating plug
for a particular circuit breaker application. The identification label
on the cover of the circuit breaker will identify the proper group
rating plug required.
Table 11. NRX Type NF Frame Rating Plugs
Group A
Group B
Group C
Frame Size
630A
*
800A
1000A
*
1200A
1250A*
1600A
RP I
n
Catalog Number
Catalog Number
Catalog Number
400
x
x
NA400T
IZMX_RP40A-400
x
x
x
NB400T
IZMX_RP40B-400
-
-
500
x
x
NA500T
IZMX_RP40A-500
x
x
x
NB500T
IZMX_RP40B-500
-
-
600
x
x
NA600T
IZMX_RP40A-600
x
x
x
NB600T
IZMX_RP40B-600
-
-
630
x
*
x
*
NA630T
IZMX_RP40A-630
x
*
x
*
x
*
NB630T
IZMX_RP40B-630
-
-
800
-
x
NA800T
IZMX_RP40A-800
x
x
x
NB800T
IZMX_RP40B-800
x
NC800T
IZMX_RP40C-800
1000
-
-
-
x
x
x
NB1000T
IZMX_RP40B-1000
x
NC1000T
IZMX_RP40C-1000
1200
-
-
-
-
x
x
NB1200T
IZMX_RP40B-1200
x
NC1200T
IZMX_RP40C-1200
1250
-
-
-
-
-
x
*
NB1250T
IZMX_RP40B-1250
x
*
NC1250T
IZMX_RP40C-1250
1600
-
-
-
-
-
-
-
x
*
NC1600T
IZMX_RP40C-1600
* IEC Only - (not UL Listed)
For the Series NRX-RF frame (
Table 12
) there are four
groupings of rating plugs available: Group D, Group E, Group
F, Group G. The identification label on the cover of the circuit
breaker will identify the proper group rating plug required if a
replacement rating plug is desired.
This value, (I
n
), is the basis for the trip unit current settings.
Refer to
Section 6: Programming Settings:
1.
The instantaneous and ground current settings (if provided)
are multiples of (I
n
).
2.
The long delay current setting, (I
r
), is a fractional multiple of
(I
n
): LONG DELAY CURRENT SETTING = (I
r
) = LD x (I
n
).
3.
The short delay current setting is a multiple of (I
r
): short
delay current setting = SD x (I
r
) = SD x [LD x (I
n
)].
ote:
N
The 400A minimum rating plug for the Digitrip 1150/1150i on a
Series NRX NF frame circuit breaker is set by the lowest level of current
protection operation.
•
WARNING
THE RATED CURRENT VALUE OF A RATING PLUG MUST NOT EXCEED
THE MAXIMUM CURRENT FRAME RATING ON THE CIRCUIT BREAKER
NAMEPLATE.
34
EATON
www.eaton.com
Effective September 2013
Instructional Leaflet IL01301064E
Operating Manual for Series NRX
Digitrip Trip Units 1150 / 1150i