Eaton 520 - Rating Plugs for Series NRX; Rating Plug Function; NF Frame Rating Plugs

23
Instruction Leaet IL01301051E
effective September 2013
Operating Manual for Series NRX
Trip Units - Digitrip™ 520/520M
EATON www.eaton.com
Section 6: Rating plugs
The rating plug defines the rated current (In) for the trip unit and is the
basis for the trip unit current settings:
1. The instantaneous and ground current setting (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 (Ir):
Short Delay current setting = SD x (I
r
) = SD x [LD x (I
n
)]
A rating plug value, (I
n
), that is less than the breakers maximum
continuous current rating (as listed on the nameplate of the breaker I
u
)
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, ratings plugs are defined per customer breaker selection
upon ordering and are installed in the factory. Field-installable kits are
also available as defined in Tables 9 and 10.
• WARNING
THE RATED CURRENT VALUE OF A RATING PLUG MUST NOT EXCEED
THE MAXIMUM CURRENT FRAME RATING AS LISTED ON THE BREAKER
NAMEPLATE.
For the Series NRX-NF frame, there are three groupings of rating plugs
available: Group A, Group B, Group C (Table 9). 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.
For the Series NRX-RF frame, there are four groupings of rating
plugs available: Group D, Group E, Group F and Group G (Table 10).
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.
Table 9. Series NRX 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)