GE Power Break II, Руководство пользователя

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Power+™ Trip Units
Long-Time Protective Functions
Long-Time Function
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Current Setting (Standard)
The adjustable long-time setting is based on multiples of "X",
the rating plug a m p rating. There are 7 possible settings from
50% to 100% of rating plug amps. This setting establishes
the current setting of the breaker, which is the current the
breaker will carry continuously without tripping. M ultiplying
the long-time setting by the rating plug value establishes the
value of "C". For example, a breaker with a 95% long-time
setting and 500-amp rating plug (X), would have a 475-amp
current setting, or value of C.
( Long-time current setting (C)= (0.50 to 1.00) x rating plug (X))
7
.8
Long-time function or current setting
Long-Time Delay (Standard)
Long-time delay varies the time it will take the breaker to trip
under sustained overload conditions. It permits the breaker
to ride through momentary predictable overloads (e.g., mo­
tor starting) without tri pping. There are 4 time bands that
provide nominal delays from 3 to 25 seconds at 600% of the
breaker's current
setting, or value of
C.
Long-time delay
10
Instantaneous Function (with Power+ Trip Units)
All Power Break® II breakers have the standard instanta­
neous tri p function. The instantaneous trip point establishes
the value of current that will tri p the breaker without inten­
tional time delay. Instantaneous tri p times are 50 millisec­
onds, or less. Instantaneous trips are the result of severe
overcurrent or short-circuit conditions. and damage to the
power system is m inimized by immediate tripping. Standard
settings are adjustable in multiples of the rating plug amp
value (X). See Table 11.1 for allowable values. The trip unit will
limit the instantaneous trip level so that the breaker with­
stand r ating is not exceeded. Maximum setting is dependent
on breaker frame size.
1.5
10 I 9
Standard instantaneous function
Short-Time Functions (Optional)
Short-Time Pickup
The short-time pickup function controls the level of high cur­
rent the breaker will withstand for short periods of time to
allow downstream devices to clear fau lts without tri pping the
breaker. Settings are adjustable in increments of the breaker
curre
nt
setting
(C).
See Table 11.1
for allowable val ues.
If
the
instantaneous setting is set for lower values of current than
the short-time function. the instantaneous function prevails.
,-1-.5
I
2.5
I
_
Short-time pickup function
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