Chapter 3 - Motor Overload Protection; Solid State Overload Protection - Toshiba 18 - 1250 A Instruction Manual

Low voltage digital solid state startern 18–1250a
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TE Series

Chapter 3 - Motor Overload Protection

MOTOR FLA (F001)
must be programmed
for unit to operate!
Examples:
H 100
100% Thermal Capacity
remaining at rest
H 057
57% Thermal Capacity
remaining after starting
(43% used)
Digital Solid State Soft Starters 18 – 1250A
3.1

Solid State Overload Protection

The TE Series Starter provides true U.L. listed I
Protection as a built-in function of the main digital processor for
maximum motor protection. It simulates the tripping action of a bi-
metallic overload relay, with the accuracy and repeatability of a digital
control system. It is adjustable over a wide range and can be easily
programmed for different trip curves.
3.1.1
Thermal Memory
The TE Series microprocessor uses a sophisticated "Thermal Register"
in the digital memory to keep track of motor heating and cooling over
time regardless of the starter's power status. By using non-volatile
memory, the TE Series does not "forget" that the motor has been
running even if power to the starter is turned off and turned back on.
Continuous overload protection is provided based on the true thermal
condition of the motor.
3.1.2
Thermal Capacity
The Thermal Register is displayed as a percentage. This percentage is
the motor's remaining thermal capacity. The percentage value begins at
100, showing that the motor is cool (has 100% of its capacity available).
As the motor heats up or moves toward an overload condition, the
percentage begins to drop. The Thermal Capacity is derived from the
programmed motor nameplate Full Load Amps (FLA) in Function F001,
the Service Factor rating in Function F002, and the Overload Trip Class
in Functions F003 and F004. Setting these functions to the proper
values provides maximum protection and eliminates nuisance tripping.
The Remaining Thermal Capacity can be viewed by using the UP or
DOWN arrow keys when in the Status Display mode. From the default
Phase A Current screen (dot on right side), press the UP arrow key 4
times to display [H100] meaning there is 100% of the Thermal Capacity
(H = Heat capacity) remaining in the motor. After starting or running, the
motor will use this capacity and the display will show a lower number.
For example, after a cold start, the display may read [H065] which
indicates that the motor has 65% of its thermal capacity remaining (35%
used). The Status Display screens cycle back to the beginning, so the
Down arrow keys can get to this display as well.
3.1.2.a
Motor Full Load (FLA) Setting
Use Function F001 to enter motor FLA as indicated on the motor
nameplate. (Do not calculate for service factor, this is programmed
separately in F002).
NOTE:
All TE Series starters are shipped from the factory with F001 set to
a default value of 0000. If F001 is left at the factory default, the unit
will not operate. If the user attempts to start the TE Series without
entering the motor nameplate FLA, the starter will Fault and the
display will read "nFLA" (no Full Load Amps).
11
2
t Thermal Overload

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