Installation, Operation and Maintenance Instructions
Flowserve Corporation1350 N. Mountain Springs Parkway1978 Foreman Dr.
Flow Control DivisionSpringville, Utah 84663-3004Cookville, TN 38501
www.flowserve.comPhone: 801 489 2233Phone: 931 432 4021
Automax Logix Series 1000 Digital Positioner
GENERAL INFORMATION
The following instructions are designed to assist in
unpacking, installing and performing maintenance as
required on Logix™ Series 1000 Digital Positioners.
Series 1000 is the term used for all the positioners
contained herein; however, specific numbers indicate
features specific to a model (i.e., Logix 1200 indicates
that the positioner uses HART
and maintenance personnel should thoroughly review
this bulletin prior to installing, operating, or performing
any maintenance on the positioner. For quick calibration
instructions, see page 11.
To avoid possible injury to personnel or damage to
valve parts, users must strictly adhere to WARNING
and CAUTION notes. Modifying this product,
substituting non-factory or inferior parts, or using
maintenance procedures other than outlined could
drastically affect performance and be hazardous to
personnel and equipment, and may void existing
warranties.
WARNING: Standard industry safety practices must be
adhered to when working on this or any other process
control product. Specifically, personal protective and
lifting devices must be used as warranted.
®
protocol). Product users
Logix 1200 Positioner Overview
The Logix 1200 positioner is a two-wire, 4-20 mA input,
digital valve positioner which utilizes the HART protocol
to allow two-way remote communications with the
positioner. The positioner can control both double and
single-acting actuators and operates with a signal as
low as 3.2 mA. Below 3.2 mA, the operation and
communication are suspended (3.2 mA is required
to restart the positioner).
Since the positioner is insensitive to supply pressure
changes and can handle supply pressures from 35 to
150 psig, a supply regulator is usually not required;
however, an air filter is required due to the close
clearances in the spool assembly.
NOTE: The air supply should conform to ISA Standard S7.3
(a dew point at least 18 degrees Fahrenheit (7° C) below
ambient temperature, particle size below five microns, and
oil content not to exceed one part per million).
Positioner Operation
The Logix 1000 positioner is an electric feedback
instrument. Positioning is based on a balance of two
signals: one proportional to the command input signal
and the other proportional to the valve stem position.
The supply pressure for the positioner pressure
modulator is tapped off the main supply and is filtered
as it passes through a field-replaceable, coalescing filter
element in the module. Next it passes through an internal
pressure regulator that regulates it to approximately
22 psig. The air then passes through an orifice that
restricts the flow and air consumption.
The pressure modulator further controls the air to
6-12 psig, using a spring-diaphragm flapper that is
attracted by an electromagnet to a nozzle. A temperature
compensated hall effect sensor mounted on a circuit
board senses the spool valve position. The hall effect
sensor and circuitry create an inner feedback loop,
which determines how much current to send to the
electromagnet for a desired spool valve position. The
electromagnet in the feedback loop varies the nozzleflapper spacing, which regulates the output pressure to
6-12 psig, proportional to the digital position algorithm.
When the command and stem position signals are equal,
the system will be in equilibrium and the valve stem will
be in the position called for by the command signal.
If these opposing signals are not equal, the spool valve
will move up (or down) and, by means of the pressure
modulator, change the output pressures and flow rate.
This causes the actuator pistons to move until the signal
of the position sensor equalizes with the command signal.
Installation, Operation and Maintenance Instructions
Flowserve Corporation1350 N. Mountain Springs Parkway1978 Foreman Dr.
Flow Control DivisionSpringville, Utah 84663-3004Cookville, TN 38501
www.flowserve.comPhone: 801 489 2233Phone: 931 432 4021
Detailed Sequence of Positioner Operations
An increase in the command signal causes the modulator
pressure to increase, pushing the spool assembly upward
from its equilibrium position. This opens the spool valve
ports, supplying air to Output 1 and exhausting air from
Output 2 (Figure 1). This causes the actuator shaft to rotate.
The shaft rotation is transmitted back to the positioner
through the stem position feedback linkage, changing
proportionally to the valve stem position. The actuator
shaft continues to rotate until the stem position signal
of the sensor increases sufficiently to counter the signal
being sent to the control algorithm. At this point, the
spool is at its equilibrium position as the pressures in
the cylinder stabilize and the air flow to the actuator
decreases. The computer will then make small null
adjustments to fine-tune the desired position and
compensate for changes in dynamic loading. A decrease
in the command signal reverses the described actions.
Mounting the Positioner
CAUTION: Positioner shaft is spring-loaded and features
mechanical stops at each end of stroke. Failure to
follow these procedures carefully may result in severe
damage to positioner. Read through entire procedure
before starting.
3. Stroke the actuator to determine direction of rotation
as shown in Figure 3. Pay specific attention to the slot
that will engage positioner shaft.
4. Carefully grasp positioner shaft with pliers as shown in
Figure 4. Turn shaft to determine direction of rotation.
Figure 3: Actuator Shaft
1. Attach positioner mounting bracket to actuator using
fasteners supplied with bracket (Figure 2). Tighten
bolts finger-tight only at this time.
2. Install coupler (if required – coupler is not required
for NAMUR mounting) on actuator shaft, making sure
it is centered.
Figure 4: Turn Positioner Shaft
5. Making sure positioner shaft rotation matches actuator
shaft rotation, place positioner on mounting bracket
(Figure 5). Make sure shafts engage. Do not insert
fasteners into positioner at this time.
6. Double-check actuator and positioner rotation. Hold
positioner against bracket with fingertips as shown in
Figure 6.
Installation, Operation and Maintenance Instructions
Flowserve Corporation1350 N. Mountain Springs Parkway1978 Foreman Dr.
Flow Control DivisionSpringville, Utah 84663-3004Cookville, TN 38501
www.flowserve.comPhone: 801 489 2233Phone: 931 432 4021
WARNING: Keep away from positioner sides, as
positioner will suddenly rotate on bracket if not
properly aligned and cause injury.
Slowly rotate the actuator. If the positioner shaft is
properly aligned, the shaft will rotate freely. If not, the
mechanical stops will grab, causing the positioner body
to rotate on bracket.
Figure 5: Positioner on Mounting Bracket
7. If the shaft is not properly aligned, repeat steps 3-6.
Otherwise, attach positioner to bracket with fasteners
included with bracket. Tighten bolts finger-tight only at
this time.
8. Stroke actuator/positioner several times to align shafts.
Tighten all fasteners.
Grounding Screw
The green grounding screw that is located inside the
termination cap should be used to provide the unit with an
adequate and reliable earth ground reference. This ground
should be tied to the same ground as the electrical
conduit. Additionally, the electrical conduit should be
earth grounded at both ends of its run.
NOTE: The green grounding screw must not be used to
terminate signal shield wires.
Compliance Voltage (Figure 7)
Output compliance voltage refers to the voltage limit that
can be provided by the current source. A current loop
system consists of the current source, wiring resistance,
barrier resistance (if present), and the Logix Series 1200
impedance. The Logix 1200 positioner requires that the
current loop system allow for a 12 VDC drop across the
positioner at maximum loop current. The 12 VDC drop
across the Logix 1200 positioner terminals is generated
by the positioner from the 4-20 mA loop current input.
CAUTION: Never connect a voltage source directly
across the positioner terminals. This could cause
permanent circuit board damage.
Tubing Positioner to Actuator
Proper tubing orientation is critical for the positioner to
function correctly and have the proper failure mode. Referring
to Figure 1, note that for air-to-open valves, the Output 1 port
of the positioner manifold, is tubed to the ‘open’ side of the
actuator. The Output 2 port of the positioner manifold is tubed
to the ‘closed’ side of the actuator. For air-to-close valves the
above configuration is reversed.
Wiring and Grounding Guidelines
Input Cable Shielding (Figure 8)
The input loop current signal to the Logix 1200 positioner
should be in shielded cable. The shields must be tied to a
ground at only one end of the cable to provide a place for
environmental electrical noise to be removed from the cable.
In general, shield wire should be connected at the source.
Installation, Operation and Maintenance Instructions
Flowserve Corporation1350 N. Mountain Springs Parkway1978 Foreman Dr.
Flow Control DivisionSpringville, Utah 84663-3004Cookville, TN 38501
www.flowserve.comPhone: 801 489 2233Phone: 931 432 4021
Figure 7: Compliance Voltage
Cable Requirements
The Logix 1200 positioner utilizes the HART Communication
protocol. This communication signal is superimposed on the
DC 4-20 mA current signal. The two frequencies used by the
HART protocol are 1200 Hz and 2200 Hz. In order to prevent
distortion of the HART communication, cable capacitance
and cable length restrictions must be calculated. The cable
length must be limited if the capacitance is too high.
Selecting a cable with lower capacitance/foot rating will allow
longer cable runs. In addition to the cable capacitance, the
network resistance also affects the allowable cable length.
In order to determine if the loop will support the Logix 1200
positioner, perform the following calculation.
Voltage =
Compliance Voltage (@Current
- Current
Shielded
Cable
)
MAX
*(R
barrier+Rwire
MAX
Field Terminations
HART Connection
Terminals
Housing EARTH
Terminal
Connect Shield at Source
4-20 mA Current Source
)
Ground
The calculated voltage must be greater than 12 VDC in
order to support the Logix 1200 positioner.
Example:DCS Compliance Voltage = 19 VDC
R
= 300 Ω
barrier
R
= 25 Ω
wire
CURRENT
= 20 mA
MAX
Voltage = 19 VDC - 0.020 A*(300 Ω + 25 Ω)
= 12.5 VDC
The voltage 12.5 VDC is greater than the required
12 VDC; therefore, this system will support the Logix
1200 positioner. The Logix 1200 positioner has an input
resistance equivalent to 600 Ω at a 20 mA input current.
In order to calculate the maximum network capacitance,
use the formula shown in the next column. (NOTE: To
control cable resistance, No. 24 AWG cable should be used
for runs less than 5000 feet. For cable runs longer than
5000 feet, No. 20 AWG cable should be used.)