Cutler-Hammer Digitrip OPTIM 550 Manuel d'instructions d'installation - Page 5

Parcourez en ligne ou téléchargez le pdf Manuel d'instructions d'installation pour {nom_de_la_catégorie} Cutler-Hammer Digitrip OPTIM 550. Cutler-Hammer Digitrip OPTIM 550 12 pages. Series c circuit breaker

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I.L. 29C508B

Source

Load

Figure 3-4 Connection Diagram

Figure 3-5 Rating Plug Installation

Effective 9/00

Grey

White

Make sure interphase barriers are properly seated in the

base and sliding handle barrier is properly seated in the

cover.

Install circuit breaker covers and pan-head

screws.Install the rating plug into the trip unit (Figure 3-5

and Table 3.1). The pins on the circuit board must line

up with the sockets in the rating plug and require only

minimal pressure to install. Do NOT attempt to force the

rating plug into the trip unit.

NOTICE

The pins on the circuit board are specifically cut,

and the sockets in the rating plug are specifically

filled to prevent an incorrect rating plug from being

installed.

Screw in and tighten the rating plug screw to secure the

rating plug.

Reset circuit breaker by moving handle to the reset

position. Move handle to the ON position. Circuit break-

er handle should remain at the ON position.

Press Push-to-trip button to check the manual tripping of

the circuit breaker.

4.0 PRINCIPLE OF OPERATION

In open air at 40°C, a L-Frame circuit breaker with a

Digitrip OPTIM 550 Trip Unit installed will carry continu-

ously up to 600 amperes without exceeding a 50°C rise

at the terminals. The calibration of the trip unit is insen-

sitive to ambient temperatures over a range of -20° to

+55°C. However the trip unit contains thermal tempera-

ture protection circuitry that initiates a trip operation for

self-protection if the internal ambient temperature at the

printed circuit board (PCB) reaches approximately

100°C. This may occur for open air temperatures above

40°C with circuit breaker currents near full load.

For ambient conditions above 40°C and where the maxi-

mum ampere rating plug has been installed, derating of

the circuit breaker frame should be considered to avoid

exceeding a safe terminal temperature operating range.

Consult Cutler-Hammer for recommendations.

4.1 GENERAL

The Digitrip OPTIM 550 Trip Unit provides a tripping sig-

nal to the flux transfer shunt trip when current and time

delay settings are exceeded. This is accomplished by

employing the Cutler-Hammer custom designed inte-

grated circuit Sµre™chip, which includes a microcom-

puter to perform its numeric and logic functions.

In the Digitrip OPTIM 550 Trip Unit, all required sensing

and tripping power to operate its protection function is

derived from the current sensors in the circuit breaker.

The secondary currents from these sensors provide the

correct input information for the protection functions, as

well as tripping power, whenever the circuit breaker is

carrying current. These current signals develop analog

voltages across the appropriate calibrating resistors.

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