Rockwell-automation 140U N-Frame Circuti Breakers Instruction Leaflet Instrukcja Użytkownika Pobierz pdf (Strona 2)

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ature operating range. Consult Allen-Bradley for recom-

mendations.

Molded Case Switches: The Molded Case Switch is

similar to the Circuit Breaker except that it does not have

a replaceable rating plug and has a different tripping

characteristic. There is a fixed instantaneous trip at

15,000 Ampere but there is no overload short delay or

ground fault trip. As a result sections 2.6, 2.7, 4, 5, 6.8

and 7 are not applicable. In the remaining sections the

term circuit breaker shall also include the molded case

switch.

100 Percent Rated N-Frame Circuit Breaker:

Circuit breakers are suitable for continuous

operation at 100 percent of the frame rating in an

enclosure which measures at least 42” height, 22 3/4”

width and 11 1/2” depth. The 800A version requires no

ventilation. The 1200A version requires 224 inch

ventila-

tion on the front face of the enclosure (72 sq. in. top, 72

sq. in. bottom, 40 sq. in. left and 40 sq. in. right). Further-

more the 1200A version has to be used with the supplied

conductor extensions and terminal barriers as shown in

Figure 2-2. Use only 90°C rated wire with ampacity

based on 75°C rated conductors. Use Copper only or

AL9CU terminals only.

Overcurrent Trip: In accordance with standards require-

ments, the trip unit initiates a trip of the circuit breaker

within two hours for an overcurrent of 135 percent, and a

trip in less time for higher overloads.

A “Thermal Memory” effect prevents the breaker from

being re-energized immediately after an overcurrent. A

“cooling off” period of up to 5 minutes is required, which

allows time for cabling to cool off.

Short delay/Instantaneous Trip: For short circuit condi-

tions that exceed the short delay pick-up settings, the trip

units initiates a trip after a delay prescribed by the I

ramp function for trip units designated L and G. A flat

response time delay action is provided by trip units desig-

nated H unless the instantaneous (I) setting is selected.

➀ Fixed rating plugs available, see table 1-2.

➁ Optional four-setting adjustable rating plugs available, see table 1-2.

➂ Using trip unit with adjustable delay (H), instantaneous pick-up is achieved when the lowest time delay set-

ting (I) is selected.

➃ Override setting fixed at frame withstand rating.

TABLE 1-1: ELECTRONIC RMS TRIP UNIT TYPES

Trip Unit Functions Electronic

L H G S

Long Time Fixed Ampere Rating ➀ with Fixed

Long Delay

Adjustable Ampere Setting with Fixed

Long Delay➁

●

Short Time Adjustable Short Time Pick-up with

Short Time Delay I

t Ramp

Adjustable Short Time Delay➂ with

Adjustable Short Time Pick-up, or

Adjustable Instantaneous Pick-up➂

●

Instantaneous Fixed Instantaneous (Override)➃●●●

Ground Fault Adjustable Ground Fault Pick-up with

Adjustable Ground Fault Time

●

40752-093(1) Effective 5/02

1 2 3 4 5 6 7 ... 15 16

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