molded case circuit breakers - Eaton Canada

266
SWITCHGEAR (TRIP UNIT RETROFIT KITS)
Digitrip RMS Retrofit Kits for
Allis Chalmers LA Breakers
INTRODUCTION AND DESCRIPTION
Allis Chalmers LA 600 Gold Breaker Retrofitted
with Digitrip RMS 810 Retrofit Kit
REPLACEMENT AND UPGRADE
Choose or create the Digitrip RMS Retrofit
Kit catalog number to match the Allis
Chalmers LA breaker type, retrofit kit type,
protection function, rating plug type, current
sensor type, CPT, and type of kit
required for application. See the example
provided on page 267.
Application Notes for Allis Chalmers LA
Power Circuit Breakers
1. Retrofit kits are for use on 50 and 60
Hz distribution systems.
2. All retrofit kits are designed for Drawout
Power Circuit Breakers only. Refer
all fixed mounted breaker applications
to the Cutler-Hammer Digitrip Retrofit
Kit Technical Service Center at
1-800-937-5487.
3. The breaker compartment doors on
the switchgear assembly must be free
of panel mounted instruments
Typical RMS 810 Retrofit Kit for Allis Chalmers
LA 600 Gold Power Circuit Breaker
(i.e. meters, instruments, control
switches, indicating lamps, etc.) or the
retrofitted breaker may interfere with
these devices when the compartment
door is closed.
4. When the Ground Fault (G) option is
selected, please observe the following:
a. For 3-phase, 3-wire solidly grounded
systems, choose quantity three current
sensors in the catalog number
development.
b. For 3-phase, 4-wire solidly grounded
systems, choose quantity four current
sensors in the catalog number
development. Three sensors are
mounted on the breaker and one
sensor is mounted on the switchgear
neutral. Hardware to mount
the current sensor on the switchgear
neutral and provisions to wire
it into the trip unit circuit (including
Digitrip RMS Retrofit Kits for Allis Chalmers,
LA power circuit breakers were first introduced
in 1991. For a complete description
of the Digitrip RMS trip system and the
features of models RMS 510, 610, 810, and
910, see page 247.
Ratings
Digitrip RMS Retrofit Kits are applied on
Allis Chalmers breakers from 600A
(LA 600) to 3000A (LA 3000). The rating
plug and the current sensor act in concert
to provide for a wide spectrum of overload
and short circuit settings.
Chronology
Digitrip RMS Retrofit Kits and replacement
trip units for Allis Chalmers LA breakers
became available in 1991. The Digitrip
RMS 510 model is the modern day replacement
for electromechanical trip device or
peak sensing solid state trip systems.
a required pair of breaker secondary
disconnecting contacts) are not
included in the kit.
5. RMS 510 Zone, 610, 810, and 910
Retrofit kits include a cell terminal
block assembly that must be installed
in the switchgear assembly. Internal
switchgear wiring to accommodate
the customer application schemes
must be added in the field.
6. RMS 610, 810, and 910 Retrofit Kits
require a customer supplied 120 Vac
source connected to the cell terminal
block assembly to power the Digitrip
RMS Digital Displays and Communications
functions (as applicable).
7. Refer all LAF (LA breakers with current
limiters) breakers to the Cutler-Hammer
Digitrip Retrofit Kit Technical Service
Center at 1-800-937-5487 for evaluation.
March 2001