SIERRA CIRCUIT BREAKERS, LLC.
"The Circuit Breaker Specialist"
Sierra Circuit Breaker is a leader in supplying Square D SEF and SED
insulated case breakers to the commercial and industrial markets. We
have a wealth of experience working with these breakers and can
repair most models.

If you have an older vintage Sierra Circuit Breake
r can help retrofil
existing switchgear with the newer Square D Micrologic™  Series trip
unit models. We have new surplus and reconditioned models in stock.
All our circuit breakers carry a full 1 year warranty. If you need
something in a hurry feel free to call us anytime
24hr/day we can get
you up and running same day in most cases.
SED364000LSG SQUARE D
Service and Repair
Recondition Test and Calibrate
Retrofit to existing switchboards
Shunt trips, Undervoltage devices, Auxillary Contacts
Square D type SEF breakers
Catalog #        frame  mounting        trip unit
SEF36250LSG     400A FIXED MT.  L,S,I,G functions   
SEF36800LSG     800A FIXED MT.  L,S,I,G functions
SEF361200LSG 1200A FIXED MT.  L,S,I,G functions
SEF361600LSG 1600A FIXED MT.  L,S,I,G functions
SEF362000LSG 2000A FIXED MT.  L,S,I,G functions
SEF362500LSG 2500A FIXED MT.  L,S,I,G functions
SEF363000LSG 3000A FIXED MT.  L,S,I,G functions
SEF364000LSG 4000A FIXED MT.  L,S,I,G functions
Trip unit suffix can be specified as :
L = long time
S= short time
I = instantaneous
G = Ground fault    *All models come with adjustable Long time and Instantaneous trip settings.
SED and SEF catalog in PDF format
General Information for tech weenies:

Square D electronic trip insulated case circuit breakers are
equipped with the MICROLOGIC Full-function Trip System. This
trip system provides adjustable tripping functions and characteristics
using true root-mean-square (rms) current sensing.
MICROLOGIC trip systems use a set of current transformers
(called CTs or sensors) to sense current, a full-function trip unit
to evaluate the current, and a tripping solenoid to trip the circuit
breaker. Adjustable rotary switches on the trip unit allow the
user to set the proper overcurrent or ground current protection
required in the electrical system. If current exceeds a set value
for longer than its set time delay, the trip system opens the
circuit breaker.
Circuit breakers are shipped with the long-time pickup switch
set at 1.0 and all other trip unit adjustments set at their lowest
settings. Actual settings required for a specific application must
be determined by a qualified consultant or plant engineer. A
coordination study is recommended to provide coordination
between all circuit breakers in the distribution system.

RMS Sensing

The sensing system on an electronic trip insulated case circuit
breaker responds to the flow of current through the circuit
breaker. Electronic trip circuit breakers are limited to ac systems
because the electronic trip system uses current transformers to
sense the current.

The MICROLOGIC trip system samples the current waveform
33 times per cycle on a 60 Hz system. It then uses this data to
calculate the true rms current through the 13th harmonic.
This true rms sensing gives accurate values for the magnitude
of a non-sinusoidal waveform. Therefore, the heating effects of
harmonically distorted waveforms are accurately evaluated.
Electronic trip circuit breakers with MICROLOGIC trip systems
can be used on 50/60 Hz systems with alternating current (ac)
to direct current (dc), dc to ac, and ac to ac converters. This
includes applications that use silicon-controlled rectifiers
(SCRs) and adjustable frequency controls.

Rating Plugs

Rating plugs are used to determine the circuit breaker ampere
rating (P) according to the following equation:
The ampere rating and the long-time pickup switch are then
combined to determine the circuit breaker continuous current
rating. For example:
Rating plugs are available with multiplier values ranging from
0.40 to 1.00. If the rating plug is not installed, the circuit breaker
will operate safely, but the trip unit will default to a rating plug
multiplier of 0.40.
Rating plugs and ammeter/trip indicators are subject to damage
from static charge. Internal damage can result if these devices
are handled by their contacts. If either device is removed from
the trip unit, it must be held against grounded metal, such as the
metal circuit breaker enclosure, for at least two seconds before
reinstalling.
Square D type SED breakers
Catalog #        frame  mounting        trip unit
SED36250LSG     400A DRAW OUT  L,S,I,G functions  
SED36800LSG     800A DRAW OUT  L,S,I,G functions
SED361200LSG 1200A DRAW OUT  L,S,I,G functions
SED361600LSG 1600A DRAW OUT  L,S,I,G functions
SED362000LSG 2000A DRAW OUT  L,S,I,G functions
SED362500LSG 2500A DRAW OUT  L,S,I,G functions
SED363000LSG 3000A DRAW OUT  L,S,I,G functions
SED364000LSG 4000A DRAW OUT  L,S,I,G functions
SQUARE D SED AND SEF
INSULATED CASE CIRCUIT BREAKERS
SED36200LI
SED36250LI
SED36300LI
SED36350LI
SED36400LI
SED36200LS
SED36250LS
SED36300LS
SED36350LS
SED36400LS
SED36200LIG
SED36250LIG
SED36300LIG
SED36350LIG
SED36400LIG
SED36200LSGS
ED36250LSG
SED36300LSG
SED36350LSG
SED36400LSG
SEHD36200LI
SEHD36250LI
SEHD36300LI
SEHD36350LI
SEHD36400LI
SEHD36200LS
SEHD36250LS
SEHD36300LS
SEHD36350LS
SEHD36400LS
SEHD36200LIG
SEHD36250LIG
SEHD36300LIG
SEHD36350LIG
SEHD36400LIG
SEHD36200LSG
SEHD36250LSG
SEHD36300LSG
SEHD36350LSG
SEHD36400LSG
SED36600LI
SED36800LI
SED36600LS
SED36800LS
SED36600LIG
SED36800LIG
SED36600LSG
SED36800LSG
SEHD36600LI
SEHD36800LI
SEHD36600LS
SEHD36800LS
SEHD36600LIG
SEHD36800LIG
SEHD36600LSG
SEHD36800LSG
SED361000LI
SED361200LI
SED361000LS
SED361200LS
SED361000LIG
SED361200LIG
SED361000LSG
SED361200LSG
SEHD361000LI
SEHD361200LI
SEHD361000LS
SEHD361200LS
SEHD361000LIG
SEHD361200LIG
SEHD361000LSG
SEHD361200LSG
SED361400LI
SED361600LI
SED361400LS
SED361600LS
SED361400LIG
SED361600LIG
SED361400LSG
SED361600LSG
SEHD361400LI
SEHD361600LI
SEHD361400LS
SEHD361600LS
SEHD361400LIG
SEHD361600LIG
SEHD361400LSG
SEHD361600LSG
SED361800LI
SED362000LI
SED361800LS
SED362000LS
SED361800LIG
SED362000LIG
SED361800LSG
SED362000LSG
SEHD361800LI
SEHD362000LI
SEHD361800LS
SEHD362000LS
SEHD361800LIG
SEHD362000LIG
SEHD361800LSG
SEHD362000LSG
SED363200LI
SED364000LI
SED363200LS
SED364000LS
SED363200LIG
SED364000LIG
SED363200LSG
SED364000LSG
SEHD363200LI
SEHD364000LI
SEHD363200LS
SEHD364000LS
SEHD363200LIG
SEHD364000LIG
SEHD363200LSG
SEHD364000LSG
SEF36200LI
SEF36250LI
SEF36300LI
SEF36350LI
SEF36400LI
SEF36200LS
SEF36250LS
SEF36300LS
SEF36350LS
SEF36400LS
SEF36200LIG
SEF36250LIG
SEF36300LIG
SEF36350LIG
SEF36400LIG
SEF36200LSGS
EF36250LSG
SEF36300LSG
SEF36350LSG
SEF36400LSG
SEHF36200LS
SEHF36250LS
SEHF36300LS
SEHF36350LS
SEHF36400LS
SEHF36200LIG
SEHF36250LIG
SEHF36300LIG
SEHF36350LIG
SEHF36400LIG
SEHF36200LSG
SEHF36250LSG
SEHF36300LSG
SEHF36350LSG
SEHF36400LSG
SEF36600LI
SEF36800LI
SEF36600LS
SEF36800LS
SEF36600LIG
SEF36800LIG
SEF36600LSG
SEF36800LSG
SEHF36600LI
SEHF36800LI
SEHF36600LS
SEHF36800LS
SEHF36600LIG
SEHF36800LIG
SEHF36600LSG
SEHF36800LSG
SEF361000LI
SEF361200LI
SEF361000LS
SEF361200LS
SEF361000LIG
SEF361200LIG
SEF361000LSG
SEF361200LSG
SEHF361000LI
SEHF361200LI
SEHF361000LS
SEHF361200LS
SEHF361000LIG
SEHF361200LIG
SEHF361000LSG
SEHF361200LSG
SEF361400LI
SEF361600LI
SEF361400LS
SEF361600LS
SEF361400LIG
SEF361600LIG
SEF361400LSG
SEF361600LSG
SEHF361400LI
SEHF361600LI
SEHF361400LS
SEHF361600LS
SEHF361400LIG
SEHF361600LIG
SEHF361400LSG
SEHF361600LSG
SEF361800LI
SEF362000LI
SEF361800LS
SEF362000LS
SEF361800LIG
SEF362000LIG
SEF361800LSG
SEF362000LSG
SEHF361800LI
SEHF362000LI
SEHF361800LS
SEHF362000LS
SEHF361800LIG
SEHF362000LIG
SEHF361800LSG
SEHF362000LSG
SEF363200LI
SEF364000LI
SEF363200LS
SEF364000LS
SEF363200LIG
SEF364000LIG
SEF363200LSG
SEF364000LSG
SEHF363200LI
SEHF364000LI
SEHF363200LS
SEHF364000LS
SEHF363200LIG
SEHF364000LIG
SEHF363200LSG
SEHF364000LSG
Square D SE Possible Catalog numbers for the SED and SEF circuit
breakers Micrologic trip units are listed below for you reference. Sierra
Circuit Breaker can help you match equivalent configurations to help
you keep your system up and running. Call or email anytime.