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7.0 AUXILIARY POWER MODULE
The Auxiliary Power Module or APM (Cat No.
PRTAAPM), illustrated in Fig. 7, is an encapsulated
power supply that requires a 1 20 Vac input at either 50 or
60 Hz. It provides an output of 32 Vdc (nominal 40 Vdc
open circuit) which can be used for testing a Digitrip RMS
5 1 0 Trip Unit.
When a drawout circuit breaker is equipped with a Digitrip
RMS 51 0 Trip Unit, it can be conveniently set and tested
while the circuit breaker is out of its cell or in its cell in the
'Test", "Disconnect" or "Withdrawn" positions by using the
Auxiliary Power Module.
The Auxiliary Power Module is equipped with a unique
plug-in connector suitable only for plugging into the keyed
receptacle in the upper right corner of a Digitrip RMS Trip
U nit as shown in Fig. 1 . This prohibits the possible use of
an incorrect type power module.
8.0 FRAME RATINGS, (WHERE APPLICABLE,
SENSOR RATINGS) AND RATING PLUGS
The
Frame Rating
of a circuit breaker is the maximum
RMS current it can carry continuously. The maximum
Short-Circuit Current Rating of the Circuit breaker are
usually related to the Frame Rating as well.
It is often times desirable to be able to choose a current
value (In), less than the full frame rating, to be the basis
for the coordination of the circuit breaker's protection
functions, without affecting its short-circuit current capa
bility. For the Digitrip 51 0 trip unit this is implemented by
changing the
Rating Plug
(and/or
Current Sensors,
where applicable - See your circuit breaker instructions
(listed in Section 9.0 below) to determine if this applies to
your circuit breaker) .
The
(Current) Sensor Rating
(where applicable) is the
maximum RMS current the circuit breaker can carry with
the specified current sensors installed. The Sensor Rat
ing can be the same or less than the Frame Rating, but
not greater.
The
Rating Plug
(See Fig. 6) fits into a special cavity to
complete the trip unit (See Fig. 1 ). Rating plugs have two
current ratings listed on their covers (See Fig. 6):
1 )
the "Must be used with Frame Rated" cur-
I.L. 29-8858
rent value (or "Sensor Rated", if applica
ble),
and 2)
"In
(Rated I)
= "
current value.
This latter value, (In) is the basis for the trip unit current
settings:
1 )
2)
3)
The Instantaneous and G round Current
Settings (if provided) are multiples of (In)
(See Sections 4.6 and 4.8)
The Long Delay Current Setting, lr , is a
multiple of (In). Long Delay Current Setting
=
lr
=
LD x (In). (See Section 4.2)
The Short Delay Current Setting (if pro
vided) is indirectly dependent upon (In) ,
because it is a multiple of lr, which in turn
is a multiple of (In).
Short Delay Current Setting
=
SD x lr
=
SD
X
LD
X
(In).
(See Section 4.4)
Rating Plugs for the Digitrip RMS 5 1 0 trip units are
marked for and may be applied on both 50 and 60 Hz
systems.
A
CAUTION
BEFORE YOU FIT THE RA TING PLUG INTO THE TRIP
UNIT,
BE SURE TO CHECK THAT THE
BREAKER
TYPE
AND
FRAME RA TING
(OR
SENSOR RA TING
IF
APPLICABLE), MA TCH THOSE PRINTED ON THE
RA TING PLUG
COVER.
INSTALLING A RA TING PLUG
THAT DOES NOT MA TCH THE BREAKER TYPE AND
FRAME RA T/NG (OR SENSOR RA TING, IF A PPLICA
BLE}, CAN PRODUCE SERIOUS MISCOORDINA TION
AND/OR FAILURE OF THE PROTECTION SYSTEM.
Complete catalog descriptions of all available rating plugs
are given in the applicable circuit breaker supplementary
instruction leaflets. (See Section 9)
Note: Rating plugs from Digitrip models 500/600nool
800 CAN NOT be used with model 5 1 0 trip units. The
connection pins are located in different positions, so
that one cannot accidentally use the incorrect kind of
plug.
Effective May 1 997
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