GE AKR-30S Manual page 17
Akr series, low voltage power circuit breaker
Hide thumbs
Also See for AKR-30S:
- Installation and maintenance instructions manual (40 pages) ,
- Manual (63 pages) ,
- Installation instructions manual (28 pages)
Table of Contents
Advertisement
Trip Devices
MicroVersaTnp" RMS-9 Tripping Functions
Long-Time Functio n
Moving from left to right on
the current axis, Figure 1 6.1,
the upper part of the time
current curve is the long
time pickup. This is the func
tion used to protect a circuit
against low magnitude over
currents. The breaker trips
because the current has
exceeded the long-time
setting. If a breaker is pro
tecting a motor, the start-up
surge (in-rush current) can
be accommodated by setting
the breaker to allow for a
momentary delay while the
motor has a chance to reach
its normal operating speed
or full load current.
Short-Time Fu nction
The middle portion of the
curve is the short-time func
tion. It is used to protect
against higher magnitude
overcurrents and low-level
short circuit faults. Overcur
rent due to short circuits is
generally in the order of 1 0
o r more times full-load cur
rent, and is measured as
symmetrical RMS (root
mean square) short-circuit
current.
Instantaneou s Fu n ction
At the bottom of the time
current curve is the protect
ive device's instantaneous
function. The instantaneous
trip point determ ines the
level at which the breaker
will trip without an intentional
time delay. This immediate
interruption occurs only as
a result of a severe overcur
rent condition, such as a
high-level short circuit, that
would damage the electrical
system if not interrupted. An
instantaneous trip can be
adjustable, depending upon
the application.
16
CURRENT SETTING
1 1X
LONG-TIME
PICKUP
7 . 1 11
10 a
.. a
" a
.
a
.
Ttme
long
" a
.. a
" a
" a
" 0
9 '
' 0
7 0
a
0
0
0
'
7
'
9
'
MULTIPLES OF CURRENT SETTING (C)
LONG-TIME
DELAY
'I
1/1
lnt
AOJUSTAaLt
MULTIPLES OF INSTANTANEOUS PICKUP
INSTANTANEOUS
PICKUP
{0
3X SX
1.5X
15X 13X
flltE.D
Appltrdl•<'ln
Det
.. ,,.,,ne�
End 01 Cu'v�
02
C2
.
5
&
11910
"
"
Hide quick links:
Advertisement
Table of Contents
