Siemens LMV5 Series Technical Instructions page 214

Technical Instructions
Document No. LV5‐1000
An error code 15 essentially means that an actuator has not reached the position it is being told
to drive to by the LMV5. The diagnostic code will detail which actuator is having the problem.
If an error code 15 is encountered, check for the following causes:
1. Binding. At full torque output, the actuator cannot move the valve or damper it is trying to
move. This is typically due to the actuator pushing against mechanical stops on the valve or
damper. Check that the actuator was properly coupled. This may also be caused by a valve
or damper that requires more torque than the actuator is capable of.
2. Temperature. All SQM... actuators are rated for a maximum operating temperature of
140°F. However, when operating temperatures exceed 120°F, the torque output of the
actuator is decreased by 15%. If this is the case, reduce the heat to the actuator.
3. Duty Cycle. All SQM... actuators are rated for a 50% duty cycle, meaning that the actuator
can only be moving half of the time. Duty cycles over 50% can cause the actuator to
overheat which reduces the torque output severely. If the actuator is constantly moving,
improve the PID settings and / or adjust parameter MinActuatorStep.
4. Flutter. This typically occurs on air or FGR dampers. Highly turbulent flow across a damper
blade can cause an alternating torque to be applied to the damper shaft. This in turn puts
an alternating torque on the actuator shaft. For example, let's say that the LMV5 is
commanding the air actuator to drive to 50.0° which is a highly turbulent spot on the air
damper. The following action may be seen:
 LMV5 sees actuator at 50.3° and repositions it counterclockwise
 LMV5 sees actuator at 49.7° and repositions it clockwise
 LMV5 sees actuator at 50.3° and repositions it counterclockwise
 LMV5 sees actuator at 49.7° and repositions it clockwise
In this scenario, eventually the LMV5 determines that the actuator cannot reach the 50.0°
position and faults with an error code 15. If a flutter is present on the air damper, a
constant torque can be applied to the air damper assembly to eliminate the effects of the
flutter.
5. Power. All of the actuators for the LMV5 run off of 24 VAC power. Measure between
terminals 12VAC1 and 12VAC2 on the actuator to ensure there are approximately 24 VAC
provided to the actuator throughout the firing range. If there are not, see Section 2 for help
on CANbus wiring. Depending on the load requirements of the system, a second
transformer may be necessary.
Section 7
Fault Positioning Actuator – Error Code 15
Page 6
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