J73KN-A-22 Omron, J73KN-A-22 Datasheet - Page 79

• Manufacturer Part Number: J73KN-A-22
• Description: CONTACT BLCK 2NO2NC FOR J7KNA-AR
• Manufacturer: Omron

Specifications of J73KN-A-22

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: J73KNA22

Description
J7MN circuit-breakers are compact, current-limiting circuit-breakers
which are optimised for load feeders. The circuit-breakers are used
for switching and protecting three-phase induction motors of up to
18,5 kW at AC 400 V and for loads with rated currents of up to 40 A.
Construction
The circuit-breakers are available in three sizes:
J7MN-12 overall width 45 mm. Max. rated current 12 A. Suitable for
3-phase induction motors of up to 5.5 kW at voltages of 400 V AC.
J7MN-25 overall width 45 mm. Max. rated current 25 A. Suitable for
3-phase induction motors of up to 11 kW at voltages of 400 V AC.
J7MN-50 overall width 55 mm. Max. rated current 40 A. Suitable for
3-phase induction motors of up to 18,5 kW at voltages of 400 V AC.
Releases
Circuit-breakers J7MN are equipped with bimetallic-based, inverse-
time delayed overload releases and with instantaneous overcurrent
releases (electromagnetic short-circuit releases).
The overload releases can be set in accordance with the load cur-
rent. The overcurrent releases are permanently set to a value 13
times the rated current and thus enable trouble-free start-up of
motors.
The scale cover can be sealed to prevent unauthorized adjustments
to the set current.
Operating mechanisms
circuit-breakers J7MN-12 are actuated via a switch operating mecha-
nism and circuit-breakers J7MN-25 and J7MN-50 via a rotary operat-
ing mechanism. If the circuit-breaker trips, the rotary operating
mechanism switches to the tripped position to indicate this. Before
the circuit-breaker is reclosed, the rotary operating mechanism must
be reset to the 0 position by hand, in order to prevent the former from
closing by mistake before the fault has been cleared.
In the case of circuit-breakers with rotary operating mechanisms,
there is an electrical signal via a signalling switch to indicate that the
circuit-breaker has tripped.
All operating mechanisms can be locked in the 0 position with a pad-
lock (shackle diameter 3.5 to 4.5 mm).
The J7MN circuit-breakers fulfil the isolation characteristics specified
in IEC 60 947-2.
Operating conditions
Circuit-breakers J7MN are suitable for use in any climate. They are
designed for operation in enclosed rooms under normal conditions
(e. g. no dust, corrosive vapours or harmful gases). Suitable enclo-
sures must be provided for installation in dusty or damp rooms.
Circuit-breakers J7MN can also be fed from below. The standards in
accordance with which the circuit-breakers are constructed, the per-
missible ambient temperatures, the maximum making and breaking
capacities, the tripping currents and other boundary conditions can
be found in the technical data and tripping characteristics.
Since the operational currents, starting currents and current peaks
vary as a result of the inrush current, even in the case of motors with
identical output ratings, the values specified for these output ratings
in the selection tables are intended as a guide only. The specific
rated and start-up data of the motor to be protected is always para-
mount to the choice of the most suitable circuit-breaker.
In order to prevent premature tripping due to phase failure sensitivity,
the circuit-breakers should always be connected in such a way that
current flows through all three main conducting paths.
Motor Protection Circuit Breaker (MPCB)
Short-circuit protection
The short-circuit releases of J7MN circuit-breakers disconnect the
faulty load feeder from the system in the event of a short circuit and
thus prevent any further damage.
Circuit-breakers with a short-circuit breaking capacity of 50 kA or
100 kA at a voltage of 400 V AC are practically short-circuit-proof at
this voltage, as higher short-circuit currents are not usually encoun-
tered at the installation point.
Back-up fuses are only necessary if the short-circuit current at the
installation point exceeds the rated ultimate short-circuit breaking
capacity of the circuit-breakers.
Motor protection
The tripping characteristics of J7MN circuit-breakers are designed
mainly to protect three-phase induction motors. The circuit-breakers
are therefore also referred to as motor circuit-breakers. The current
of the motor to be protected is set with the aid of the scale.
Circuit-breakers with thermal overload releases are normally
designed in accordance with release Class 10.
Line protection
J7MN circuit-breakers for motor protection are also suitable for line
protection. In order to prevent premature tripping due to phase failure
sensitivity, the three conducting paths must always be uniformly
loaded. The conducting paths must be connected in series in the
case of single-phase loads.
The J7MN circuit-breakers meet the isolation conditions of
IEC 60 947-3 as well as the additional test conditions for circuit-
breakers with isolation characteristics specified in IEC 60 947-2. Tak-
ing IEC 60 204-1 into consideration, they can thus be implemented
as main and EMERGENCY STOP switches.
Door-coupling rotary operating mechanism do not fulfil the isolation
characteristics specified in IEC 60 947-2. Door-coupling rotary oper-
ating mechanism according isolation characteristics specified in
IEC 60 947-2 on request.
J7MN
H-79