Power+™ trip units chapter 2. trip unit setup, 2–1 overview, 2–2 long-time pickup – GE Industrial Solutions WavePro Manuel d'utilisation

Page 11: 2–3 long-time delay

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Power+™ Trip Units

Chapter 2. Trip Unit Setup

5

2–1 Overview

All of the Trip Unit protective functions are set with the
rotary selector switches on the front of the unit. Table 7
contains a summary of the functions and the available
settings.

Most of the selector switch scales (all but instantaneous
pickup) have a heavy curved line, with an arrowhead on
one end, connecting the low and high ends of the scale.
When the switch points anywhere within this region, the
highest value at the end of the line opposite the arrowhead
is the active setting.

WavePro circuit breakers are available with Power+™ as
well as MicroVersaTrip Plus and MicroVersaTrip PM Trip
Units. There are two different sets of abbreviations used to
describe the same TripUnit settings in the documentation
and on the Trip Unit labels. These abbreviations are listed
in Table 8.

Trip Unit Setting

Abbreviations

Rating Plug rating, A

xIn

X

Current Sensor rating, A

xCT

S

Current setting, A

xLT

C

Table 8. Comparison of Trip Unit settings abbreviations.

2–2 Long-Time Pickup

The long-time pickup set point establishes the breaker’s
nominal ampere rating, C, as a fraction of the rating plug
current, X. The choices for C are .5, .6, .7, .8, .9, .95, 1.0,
and 1.1 times X. Figure 3 illustrates the long-time pickup
settings.

Figure 3. Time-current curve illustrating long-time pickup.

2–3 Long-Time Delay

The long-time delay function allows normal momentary
overloads without nuisance tripping. The nominal time
delays at the lower limits of the bands for 600% of the
long-time current set point, C, for the four selectable bands
are listed in Table 9. Figure 4 illustrates the effect of this
delay on the trip time.

Band

Delay, sec

1

2.4

2

4.9

3

9.8

4

20

Table 9. Nominal delays for the long-time delay bands.

Parameter

Pickup Settings

Delay Settings

Delay Curve

Long-Time Trip

.5, .6, .7, .8, .9, .95, 1.0, 1.1

multiple of Rating Plug Current (X)

2.4, 4.9, 9.8, 20 seconds

(Bands 1, 2, 3, 4)

Fixed

Short-Time Trip

1.5, 2, 2.5, 3, 4, 5, 7, 9

multiple of Long-Time setting (C)

.10, .21, .35 second

(Min, Int, Max)

I

2

T In, I

2

T Out

Instantaneous Trip

1.5, 2, 3, 5, 7, 9, 10

1

, 13

1

, 15

1

multiple of Rating Plug Current (X)

No delay

N/A

Ground-Fault Trip

.2, .25, .3, .35, .4, .45, .5, .6

multiple of Sensor rating (S)

2

.10, .21, .35 seconds

(Min, Int, Max)

I

2

T In, I

2

T Out

1

Maximum setting is limited by the frame size.

2

Maximum setting is limited to 1200 A. Pickup settings are deterimined by the breaker frame size

Table 7. Summary of protective functions and setting values for each.

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