Brochure

PowerPact H-, J-, and L-Frame Circuit Breakers
Circuit Breakers
27
02/2016
© 2011–2016 Schneider Electric
All Rights Reserved
Special Applications
Protection of Industrial Control Panels
PowerPact H-, J-, and L-frame circuit breakers are also used in industrial control panels. They serve as
an incoming devices or can be combined with contactors to protect motor feeders:
• compliance with worldwide standards including IEC 60947-2 and UL 508 / CSA C22.2 N°14
• overload and short-circuit protection
• installation in universal and functional type
PowerPact H-, J-, and L-frame circuit breakers equipped for motor protection functions as described in
the following pages can be used in industrial control panels. The accessories for the PowerPact H-, J-,
and L-frame circuit breakers are suitable for the special needs of these applications.
400 Hz Applications
Impact on Protective Devices
The current in 400 Hz systems have higher losses caused by eddy currents and an increase in the skin
effect (reduction in the useful cross-sectional area of conductors). The higher losses cause additional
temperature rise in circuit breakers subjected to the higher frequency current. To remain within the
rated temperature-rise limits of devices, current derating is required. For circuit breakers equipped with
Micrologic electronic trip units, only the current rating (Ir) must be derated. See Table 14. On circuit
breakers equipped with thermal-magnetic trip units, the current rating (In) must be derated and the
magnetic trip setting Im must be increased. See Table 15.
Breaking Capacity in 400 Hz, 480 V Systems
The power levels of 400 Hz applications rarely exceed a few hundred kW with relatively low short-
circuit currents, generally not exceeding four times the rated current.
Micrologic Electronic Trip Units
Micrologic™ 3.2/3, 5.2/3 A or E and 6.2/3 with A or E measurement functions are suitable for 400 Hz.
The use of electronics offers the advantage of greater operating stability when the frequency varies.
However the units are still subject to temperature rise caused by the frequency.
The practical consequences are:
• limit settings: see the I
r
derating table below
• the long-time, short-time and instantaneous pick-ups are not modified (see pages 87 or 89)
• the accuracy of the displayed measurements is 2% (Class II)
Circuit Breaker Max. Breaking Capacity AIR at 400 Hz
H-frame 10 kA
J-frame 10 kA
L-frame 10 kA
Table 14: Current Derating Maximum I
r
Setting
Circuit Breaker Maximum Setting Coefficient Max I
r
Setting at 400 Hz
H-Frame, 150 A 0.9 135
J-Frame, 250 A 0.9 225
L-Frame, 400 A 0.8 320
L-Frame, 600 A 0.65 390