Specifications

Information and Instructions
3
General
JD and LD-Frame Solid State Sensitrip style breakers of the
Sentron family are for use in individual enclosures, switch-
boards, and power distribution panel boards. They are
available both as 80% and 100% rated devices and in three
interruption ranges as shown in the table below.
Symetrical RMS Amperes UL Interruption Ratings
Interruption
Rating
Type 240V AC 480V AC 600V AC
Standard SJD6-SLD6 65kA 35kA 25kA
High Rating SHJD6-SHLD6 100kA 65kA 35kA
Current Limiting SCJD6-SCLD6 200kA 150kA 100kA
SCJD6 and SCLD6 type circuit breakers are designed to
meet the requirement of current limiting as outlined in the
National Electric Code, article 240-11 and UL 489 standards.
SCJD6 and SCLD6 type circuit breakers are fuseless and
therefore eliminate the requirement of locating and replacing
blown fuses should a high current fault occur. The common
trip feature of the circuit breaker is completely retained so that
all poles of the circuit breaker open when caused to trip due
to an overcurrent condition.
Pressure wire connectors, suitable for use with aluminum or
copper wire are available for all JD and LD-Frame circuit
breakers. Rear connection studs or plug-in connector as-
semblies are also available. The latter mounting arrangement
permits the removal of the circuit breaker from its leads
without physically coming in contact with either line or load
terminals. UL listed special features such as a shunt trip,
auxiliary and alarm switches and undervoltage trip devices
are available for internal mounting. The installation and/or
removal of these devices is to be accomplished by qualified
personnel only.
The chart below illustrates the functions available in all
Sentron Solid State Sensitrip circuit breakers.
Adjustments
Breaker Suffix Letters
No
Suffix
G NT NGT
Long Time Adj.
Current Setting
✓ ✓ ✓ ✓
Adj.
Long Time Delay
✓ ✓ ✓ ✓
Adj.
Instantaneous
Setting
✓ ✓ ✓ ✓
Adj.
Short Time Pick Up
✓ ✓
Adj.
Short Time Delay
✓ ✓
Adj.
Short Time I²t
Pick Up
✓ ✓
Adj.
Ground Fault
Pick Up
✓ ✓
Adj.
Ground Fault Delay
✓ ✓
NOTES: “G” suffix in catalog number denotes circuit breaker for 3 phase, 3 wire circuits. For
3 phase, 4 wire, order correct 4th wire (neutral) transformer as separate and additional item.
For 100% rated breakers, an “H” is added at the end of the normal catalog number
General Information
Circuit Breaker Operation
With the mechanism latched and the contacts open, the
operating handle will be in the OFF position. Moving the
handle to the ON position closes the contacts and establishes
a circuit through the circuit breaker. Under overload or short
circuit conditions sufficient to trip or open the breaker auto-
matically, the operating handle moves to a position between
ON and OFF. To relatch the circuit breaker after automatic
operation, move the operating handle to the extreme OFF
position. The circuit breaker is now ready for reclosing.
The overcenter toggle mechanism is trip free of the operating
handle. The circuit breaker, therefore, cannot be held closed
by means of the handle should a tripping condition exist. After
automatic operation, the handle will assume an intermediate
position between ON and OFF, thus displaying a clear
indication of tripping.
NOTE: The lockable cover shield prevents unauthorized
access to trip unit. See photo on page 53.
Manual Operation
Manual operation of the circuit breaker is controlled by the
circuit breaker handle and the PUSH-TO-TRIP button. The
circuit breaker handle has three indicating positions, two of
which are molded into the handle to indicate ON and OFF.
The third position indicates a TRIP position and is between
the ON and OFF positions.
A. Circuit Breaker Reset After tripping, the circuit breaker
is reset by moving the circuit breaker handle to the reset
position and then moving the handle to the ON position.
B. The PUSH-TO-TRIP Button PUSH-TO-TRIP button
checks the tripping function and is used to manually
exercise the operating mechanism.