39
I20683 - Subject to change.
TNF
Installation Instructions
Initialization of the TNF24-SR
When power is initially applied, the microprocessor recognizes
that the actuator is at full fail-safe and uses this position as
the base for all of its position calculations. The microprocessor
will retain the initialized zero during short power failures of up
to 20 seconds. For power failures greater than 20 seconds the
actuator would naturally return to it full fail-safe position prior
to the microprocessor losing its memory. When power is
applied again, the actuator will re-initialize the zero position.
The microprocessor will keep count of these short power
failures until 16 occur. At this point, the microprocessor will
automatically drive the actuator to its zero position and
re-initialize to correct for any possible error accumulation.
Motor Position Detection
A brushless DC motors eliminate the need for potentiometers for
positioning. Inside the motor are three “Hall Effect” sensors.
These sensors detect the spinning rotor and send pulses to the
microprocessor which counts the pulses and calculates the posi-
tion to within 1/3 of a revolution of the motor.
Overload Protection
The TNF24-SR actuators are protected from overload at all
angles of rotation. The on board microprocessor constantly
monitors the rotation of the DC drive motor inside the actuator
and stops the pulses to the motor when it senses a stall con-
dition. The DC motor remains energized and produces full
rated torque to the load. This helps ensure that dampers are
fully closed and that edge and blade seals are always properly
compressed.
Brushless DC Motor Operation
The brushless DC motor spins by reversing the poles of sta-
tionary electromagnets housed inside rotating permanent
magnets. The electromagnetic poles are switched by a micro-
processor and a special ASIC (Application Specific Integrated
Circuit). Unlike the conventional DC motor, there are no
brushes to wear or commutators to foul.
Additional Operational Information for TNF24-SR Proportional Actuators
Satisfied
Control Position
Satisfied
Control Position
Minimum
Control Resolution
Minimum Reversed
Control Deadband
Prior to Normal Control
80 mV
200 mV
TNF actuator responds to a 80 mV signal
when not changing direction from stop.
TNF actuator responds to a 200 mV signal
when reversing direction from stop position.
TNF24-SR actuators have built-in brushless DC motors which provide better accuracy and longer service life.
The TNF24-SR actuators are designed with a unique non-symmetrical deadband. The actuator follows an increasing or
decreasing control signal with a 80 mV resolution. If the signal changes in the opposite direction, the actuator will not respond
until the control signal changes by 200 mV. This allows these actuators to track even the slightest deviation very accurately,
yet allowing the actuator to “wait” for a much larger change in control signal due to control signal instability.
Control Accuracy and Stability
Summary of Contents for TRANE TAF Series
Page 7: ...Notes Work Pad 7 I20683 Subject to change...
Page 27: ...27 I20683 Subject to change TAF Notes Work Pad...
Page 57: ...57 I20683 Subject to change TLF Notes Work Pad...
Page 73: ...73 I20683 Subject to change TTF Notes Work Pad...
Page 98: ...98 I20683 Subject to change Notes Work Pad...
Page 165: ...165 I20683 Subject to change Wiring Guide Notes Work Pad...
Page 166: ...Notes Work Pad 166 I20683 Subject to change...
