Emerson Fisher Level-Trol 2502R, Fisher Level-Trol 2502CR, Fisher Level-Trol 2502, Fisher Level-Trol 2502C, Fisher Level-Trol 2502F Instruction Manual
...
Instruction Manual
Form 1446
November 2006
2502 Series Controllers
2502 Series Level-TrolR Controller
Contents
Introduction 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Scope of Manual 1. . . . . . . . . . . . . . . . . . . . . . . . .
Description 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications 2. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Educational Services 2. . . . . . . . . . . . . . . . . . . . . .
Installation 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
249 Series Sensors 4. . . . . . . . . . . . . . . . . . . . . . .
Uncrating 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Controller Orientation 5. . . . . . . . . . . . . . . . . . . . .
Controller-Sensor Action 5. . . . . . . . . . . . . . . . . . .
Mounting Caged Sensors 6. . . . . . . . . . . . . . . . . .
Mounting Cageless Sensors 7. . . . . . . . . . . . . . .
Side-Mounted Sensor 8. . . . . . . . . . . . . . . . . . . .
Top-Mounted Sensor 8. . . . . . . . . . . . . . . . . . . .
Regulator Supply Pressure 9. . . . . . . . . . . . . . . .
Prestartup Checks 9. . . . . . . . . . . . . . . . . . . . . . . . .
Adjustments 11. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Level Set Adjustment 11. . . . . . . . . . . . . . . . . . .
Proportional Band Adjustment 11. . . . . . . . . . . .
Reset Adjustment 11. . . . . . . . . . . . . . . . . . . . . .
Differential Relief Adjustment 12. . . . . . . . . . . .
Calibration 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Precalibration Requirements 12. . . . . . . . . . . . . .
Wet Calibration 12. . . . . . . . . . . . . . . . . . . . . . . . .
Dry Calibration 12. . . . . . . . . . . . . . . . . . . . . . . . .
Controller and Torque Tube Arm
Disassembly 12. . . . . . . . . . . . . . . . . . . . . . . .
Determining Suspended Weight
for Calibration 13. . . . . . . . . . . . . . . . . . . . . . .
Calibration Procedure 14. . . . . . . . . . . . . . . . . . . .
Startup 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Principle of Operation 15. . . . . . . . . . . . . . . . . . . . .
Type 2502 Controller 15. . . . . . . . . . . . . . . . . . . . .
Type 2502F Controller with Reset
Relief Valve 17. . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting 18. . . . . . . . . . . . . . . . . . . . . . . . .
Removing Controller from Sensor 18. . . . . . . . . .
Changing Mounting Method 20. . . . . . . . . . . . . . .
Installing Controller on Sensor 20. . . . . . . . . . . . .
Changing Proportional, Reset, or
Differential Relief Valve 21. . . . . . . . . . . . . . . . .
Testing Relay Dead Band 21. . . . . . . . . . . . . . . . .
Changing Relay 21. . . . . . . . . . . . . . . . . . . . . . . . .
Introduction
Scope of Manual
This instruction manual provides installation,
operating, calibration, and maintenance procedures
for 2502 Series pneumatic controllers (figure 1) used
in combination with 249 Series level sensors.
This manual does not include regulator or sensor
installation or maintenance procedures. For this
information, refer to the instruction manual for the
appropriate regulator and 249 Series level sensor.
W8334
Figure 1. Type 2502 Controller Mounted on
Type 249B Sensor
Replacing Bellows 22. . . . . . . . . . . . . . . . . . . . . . .
Reversing Action 22. . . . . . . . . . . . . . . . . . . . . . . .
Parts Ordering 23. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Kits 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts List 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TYPE 2502
CONTROLLER
249B SERIES SENSOR
www.Fisher.com
D200126X012
2502 Series Controllers
Instruction Manual
Form 1446
November 2006
No person may install, operate, or maintain this
product without first D being fully trained and
qualified in valve, actuator, and accessory
installation, operation, and maintenance, and D
carefully reading and understanding the contents of
this manual. If you have any questions about these
instructions, contact your Emerson Process
Managementt sales office before proceeding.
Description
The Type 2502 Level-TrolR controller described in
this manual provides proportional-plus-reset and
proportional-plus-reset with differential relief valve
control. The controller output is a pneumatic signal
that operates a final control element. These
controllers are designed to control liquid level, the
level of interface between two liquids, or density
(specific gravity). Each unit consists of a 249 Series
liquid level sensor and a 2502 Series pneumatic
controller.
Refer to the Principle of Operation section for a more
comprehensive discussion of how the Type 2502
pneumatic controller operates.
Specifications
Table 1 gives general specifications for Type 2502
Series controllers.
Educational Services
Note
Neither Emerson, Emerson Process
Management, nor any of their affiliated
entities assumes responsibility for the
selection, use, and maintenance of any
product. Responsibility for the
selection, use, and maintenance of any
product remains with the purchaser
and end-user.
Installation
The 2502 Series controllers are used in combination
with 249 Series sensors, and unless ordered
separately, the controller will be attached to the
sensor.
WARNING
Wear protective eyewear, gloves and
clothing whenever possible when
performing any installation operations
to avoid personal injury.
Check with your process or safety
engineer for any additional measures
that must be taken to protect against
process media.
If installing into an existing
application, also refer to the WARNING
at the beginning of the Maintenance
section in this instruction manual.
For information on available courses for the Type
2502 Series Level-Trol Controller, as well as a
variety of other products, contact:
Emerson Process Management
Educational Services, Registration
P.O. Box 190; 301 S. 1st Ave.
Marshalltown, IA 50158−2823
Phone: 800−338−8155 or
Phone: 641−754−3771
Fax: 641−754−3431
e-mail: education@emersonprocess.com
2
WARNING
Personal injury or property damage
may result from fire or explosion if
natural gas is used as the supply
medium and preventative measures
are not taken. Preventative measures
may include: Re-evaluating the
hazardous area classification,
ensuring adequate ventilation, and the
removal of any ignition sources.
Instruction Manual
Form 1446
November 2006
2502 Series Controllers
Table 1. Specifications
Available Configurations
Type 2502: A direct-acting controller which
provides proportional-plus-reset control
Type 2502C: A Type 2502 with a level indicator
assembly
Type 2502F: A Type 2502 with a differential relief
valve
These type numbered products are also
available with reverse action. For example,
Type 2502R, Type 2502CR, and 2502FR
Input Signal
(1)
Liquid Level or Liquid-to-Liquid Interface
Level: From 0 to 100 percent of displacer
length—standard lengths for all sensors are 356
mm (14 inches) or 813 mm (32 inches). Other
lengths available depending on sensor
construction
Liquid Density: From 0 to 100 percent of
displacement force change obtained with given
displacer volume—standard volumes are 980 cm
(60 inches3) for Types 249C and 249CP sensors,
or 1640 cm
3
(100 inches3) for most other 249
Series sensors; other volumes available
depending on construction
Output Signal
(1)
0.2 to 1.0 bar (3 to 15 psig) or 0.4 to 2.0 bar (6 to
30 psig)
Action: Field reversible between direct
(increasing liquid or interface level or specific
gravity increases output pressure) and reverse
(increasing liquid or interface level or specific
gravity decreases output pressure)
Area Ratio of Relay Diaphragms
3:1
Supply Medium
Air or Natural Gas
(2)
Supply Pressure Requirement
(3)
1.4 bar
output signal or 2.4 bar
(20 psig) for 0.2 to 1.0 bar (3 to 15 psig)
(3)
(35 psig) for 0.4 to 2.0
bar (6 to 30 psig) output signal
3
(continued)
Maximum Supply Pressure
(4)
3.4 bar (50 psig)
Supply Pressure Consumption
At 1.4 bar (20 Psig)
Minimum: 0.11 normal m
proportional band setting of 0 or 200 percent
Maximum: 0.72 normal m
(5)
3
/h (4.2 scfh) at
3
/h (27 scfh) at
proportional band setting of 100 percent
At 2.4 bar (35 psig)
Minimum: 0.2 normal m
band setting of 0 or 200 percent
Maximum: 1.1 normal m
3
/h (7 scfh) at proportional
3
/h (42 scfh) at
proportional band setting of 100 percent
Performance
Hysteresis: 0.6 percent of output pressure
change at 100 percent of proportional band
Repeatability
or displacement force change
Dead Band
(1)
: 0.2 percent of displacer length
(1)
: 0.05 percent of proportional band
or span
Typical Frequency Response
(1)
: 4 Hz and
90-degree phase shift at 100 percent of
proportional band with output piped to typical
instrument bellows using 6.1 meters (20 feet) of
6.4 mm (1/4 inch) tubing
Ambient Temperature Error: $1.5 percent of
output pressure change per 50_F (28_C) of
temperature change at 100 percent of
proportional band when using sensor with
standard-wall N05500 torque tube with 249 Series
sensors
(1)
Reset
: Adjustable from 0.01 to 74 minutes per
repeat (100 to 0.01 repeats per minute)
Differential Relief (Type 2502F and 2502FR
Controllers Only): Adjustable from 0.1 to 0.48
bar differential (2 to 7 psi) to relieve excessive
difference between proportional and reset
pressures. Differential relief can be switched
between rising output pressure and falling output
pressure.
Standard Tubing Connections
1/4-inch NPT female
Maximum Working Pressures (Sensors Only)
Consistent with applicable ASME
pressure/temperature ratings
3
2502 Series Controllers
Instruction Manual
Form 1446
November 2006
Table 1. Specifications (continued)
Hazardous Area Classification
Declaration of SEP
2502 Series controllers comply with the
requirements of ATEX Group II Category 2 Gas
and Dust
Fisher Controls International LLC declares this
product to be in compliance with Article 3
paragraph 3 of the Pressure Equipment Directive
(PED) 97 / 23 / EC. It was designed and
Operative Ambient Temperatures
(4)
Standard Construction: 40 to 71_C (*40 to
manufactured in accordance with Sound
Engineering Practice (SEP) and cannot bear the
CE marking related to PED compliance.
160_F*)
High Temperature Construction: *18 to 104_C
(0 to 220_F).
See figure 2.
1. Term defined in ISA Standard S51.1.
2. Natural gas should contain no more that 20 ppm of H2S.
3. Control and stability may be impaired if this pressure is exceeded.
4. The pressure/temperature limits in this document, and any applicable standard or code limitation should not be exceeded.
5. Normal cubic meters per hour (m
AMBIENT TEMPERATURE (_C)
−18 −10
1100
_
800
400
0
USE INSULATOR (CAUTION! IF AMBIENT DEWPOINT IS
ABOVE PROCESS TEMPERATURE, ICE FORMATION MAY
PROCESS TEMPERATURE ( F)
CAUSE INSTRUMENT MALFUNCTION AND REDUCE
INSULATOR EFFECTIVENESS.)
−20 −29
0 20 40 60 80 100 120 140 160
01020
HEAT INSULATOR
REQUIRED
NO INSULATOR NECESSARY
AMBIENT TEMPERATURE (_F)
STANDARD CONTROLLER OR TRANSMITTER
3
/hr) at 0_C and 1.01325 bar. Scfh=standard cubic feet per hour at 60_F and 14.7 psia .
30 40 50 60 70
TOO
HOT
71
593
500
_
400
300
200
100
0
−18 −10
1100
_
800
400
0
PROCESS TEMPERATURE ( F)
PROCESS TEMPERATURE ( C)
−20 −29
0 20 40 60 80 100 120 140 200
NOTE: FOR SERVICE BELOW −29_C (−20_F) CONTACT FACTORY.
B1413-1/IL
However, the product may bear the CE marking
to indicate compliance with other applicable EC
Directives.
01020
HEAT INSULATOR
REQUIRED
NO INSULATOR NECESSARY
USE INSULATOR (CAUTION! IF AMBIENT DEWPOINT IS
ABOVE PROCESS TEMPERATURE, ICE FORMATION MAY
CAUSE INSTRUMENT MALFUNCTION AND REDUCE
INSULATOR EFFECTIVENESS.)
HIGH-TEMPERATURE CONTROLLER OR TRANSMITTER
AMBIENT TEMPERATURE (_C)
30 40 50 60 70
AMBIENT TEMPERATURE (_F)
80 90
TOO
HOT
180160
93
593
500
400
300
200
100
0
Figure 2. Guidelines for Use of Optional Heat Insulator Assembly
249 Series Sensors
D The Type 249, 249B, 249C, 249K, and 249L
sensors side-mount on the vessel with the displacer
mounted inside a cage (caged) outside the vessel.
D The Type 249BP and 249CP sensors
top-mount on the vessel with the displacer hanging
down into the vessel (cageless).
D The Type 249V sensor side-mounts on the
vessel with the displacer hanging out into the vessel
(cageless).
D The Type 249W sensor top-mounts on the
vessel or on a customer supplied cage.
4
External sensors provide more stable operation than
do internal sensors for vessels with internal
obstructions or considerable internal turbulence.
WARNING
When replacing the sensor assembly,
the displacer may retain process liquid
or pressure. Personal injury or
property damage due to sudden
release of pressure, contact with
hazardous liquid, fire, or explosion can
be caused by puncturing, heating, or
repairing a displacer that is retaining
Instruction Manual
Form 1446
November 2006
2502 Series Controllers
process pressure or liquid. This
danger may not be readily apparent
when disassembling the sensor or
removing the displacer. Before
disassembling the sensor or removing
the displacer, observe the more
specific warning provided in the
sensor instruction manual.
Uncrating
Unless ordered separately, the controller will be
attached to the sensor when shipped. Carefully
uncrate the assembly.
CAUTION
If the sensor has a thin-walled torque
tube, always support the displacer if
the travel stop must be removed. A
thin-walled torque tube has a T
stamped on the sensor end flange (not
visible unless the controller is
removed from the sensor).
Note
Caged sensors have a rod and block
installed on each end of the displacer
to protect the displacer in shipping.
Remove these parts before installing
the sensor to allow the displacer to
function properly.
Caged sensors will be shipped with the displacer
installed in the cage. If the sensor is ordered with a
tubular gauge glass, the gauge glass will be crated
separately and must be installed at the site. Be
certain that the cage equalizing connections are not
plugged with foreign material.
A caged sensor has a damping plate installed in the
lower screwed or flanged connection to provide
more stable operation. If the process liquid could
clog the plate opening with sediment, then remove
the damping plate. For screwed connections, use a
1/2-inch hexagon wrench to unscrew the damping
plate. For flanged connections, use a screwdriver to
pry the damping plate out of the flange.
PRESSURE
REGULATOR
1/4”-18 NPT
OUTPUT
CONNECTION
LOCKNUT
VENT
Figure 3. Pressure Connections
ADJUSTING
SCREW
1/4”-18 NPT
SUPPLY
CONNECTION
DRAIN VALVE
not attached to the displacer rod. Inspect the
displacer and replace if it is dented. A dent may
reduce the pressure rating of the displacer.
Controller Orientation
A controller is to be mounted with the vent opening
pointing downward as shown in figure 3. This
orientation is necessary to ensure draining of
accumulated moisture. The controller is attached to
the sensor in one or the other of the mounting
positions shown in figure 4: Right hand (with the
case to the right of the displacer when looking at the
front of the case) or left hand (with the case to the
left of the displacer). The mounting position can be
changed in the field if required; refer to the
appropriate sensor manual for instructions.
Changing this mounting position will change
controller action from direct to reverse, or vice versa.
All caged sensors have a rotatable head. That is, the
controller may be positioned at any of eight alternate
positions around the cage as indicated by the
numbers 1 through 8 in figure 4. To rotate the head,
remove the head flange bolts and nuts and position
the head as desired.
Controller-Sensor Action
The following controller description is for right-hand
mounting. Left-hand mounting produces an output
signal with the opposite action. Figure 4 shows cage
head mounting positions.
For right-hand mounting:
D Direct Action—Increasing liquid or interface
level, or density, increases the output signal.
A cageless sensor is shipped with the displacer
separated from the sensor assembly. A displacer
longer than 813 mm (32 inches) is crated separately.
A shorter displacer is crated with the sensor, but is
D Reverse Action—Decreasing liquid or interface
level, or density, increases the output signal. A
factory-supplied reverse-acting unit has the suffix
letter R added to the type number.
5
2502 Series Controllers
Instruction Manual
Form 1446
November 2006
RIGHT-HAND MOUNTING
STYLE 1: TOP
AND BOTTOM
SCREWED: S1
FLANGED: F1
STYLE 2: UPPER
AND LOWER SIDE
STYLE 2: TOP
AND LOWER SIDE
SCREWED: S2
FLANGED: F2
STYLE 2: UPPER
SIDE AND BOTTOM
AH9150−A
A2613−2/IL
Figure 4. Cage Head Mounting Positions
LEFT-HAND MOUNTING
Mounting Caged Sensor
Note
The cage must be installed plumb so
that the displacer does not touch the
cage wall. Should the displacer touch
the cage wall, the unit will transmit an
erroneous output signal.
Note
If the controller is not mounted on the
sensor, refer to the Installing
Controller on Sensor section. This
section also provides instructions for
adding a heat insulator to a unit.
A1271−2/IL
SCREWED: S3
FLANGED: F3
Figure 5. Cage Connection Styles
SCREWED: S4
FLANGED: F5
Cage connections will normally be either 1-1/2 or
2-inch screwed or flanged. Figure 5 shows the
combinations. With flanged connections, use
standard gaskets or other flat-sheet gaskets
compatible with the process liquid. Spiral wound
gaskets without compression-controlling centering
rings cannot be used for flanged connections.
Mount the cage by running equalizing lines between
the cage connections and the vessel (figure 6). A
shutoff or hand valve with a 1-1/2 inch diameter or
larger port should be installed in each of the
equalizing lines. Also install a drain between the
cage and shutoff or hand valve whenever the bottom
cage line has a liquid-trapping low point.
On liquid or interface level applications, position the
sensor so that the line marked FLOAT CENTER on
the cage is located as close as possible to the center
of the liquid level or interface level range being
measured. Also consider installing a gauge glass
either on the vessel, or on the sensor cage (if the
cage is tapped for a gauge).
6
Instruction Manual
Form 1446
November 2006
CENTER OF
LIQUID OR
INTERFACE
LEVEL
SHUTOFF
VALVES
VENT
EQUALIZING
LINE
2502 Series Controllers
DRAIN
DF5379-A
A6771/IL
Figure 6. Caged Sensor Mounting
Mounting Cageless Sensor
Note
If a stillwell is used, it must be
installed plumb so that the displacer
does not touch the wall of the stillwell.
Should the displacer touch the wall
while the unit is in service, the unit will
transmit an erroneous output signal.
Since the displacer hangs inside the vessel, provide
a stillwell around the displacer if the liquid is in a
state of continuous agitation to avoid excessive
turbulence around the displacer.
W0645-1
SIDE (SHOWING STILLWELL)
TOP
MOUNTED
Note
Displacers used in an interface level
application must be completely
submerged during operation. If
displacers aren’t completely
submerged they will not calibrate or
perform properly. To obtain the
desired controller sensitivity may
require using either a thin-wall torque
tube, an oversized displacer, or both.
CF5380-A
A3893/IL
TOP
Figure 7. Cageless Sensor Mounting
7
2502 Series Controllers
Note
Instruction Manual
Form 1446
November 2006
If the controller is not mounted on the
sensor, refer to the Installing
Controller on Sensor section. This
section also provides instructions for
adding a heat insulator to a unit.
Attach a cageless sensor to a flanged connection on
the vessel as shown in figure 7. For interface or
liquid level applications, install a gauge glass on the
vessel.
CAUTION
If the displacer is to be inserted into
the vessel before being attached to the
displacer rod, provide a suitable
means of supporting the displacer to
prevent it from dropping into the
vessel and suffering damage.
To help support a Type 249BP or 249CP displacer,
install the displacer stem and stem end piece, or a
threaded rod, into the 1/4 inch-28 UNF threaded
hole in the displacer spud or stem end piece (figure
8). On the Type 249BP with optional travel stop, the
stem end piece pins will secure the displacer as long
as the travel stop plate is installed and the sensor
head is in position.
Side-Mounted Sensor
DISPLACER
STEM
END PIECE
DISPLACER ROD
DISPLACER
STEM
EXTENSION
W0229-1A/IL
DISPLACER
SPUD
W0228-1A/IL
Figure 8. Displacer/Displacer Rod Connections
TYPE 249V
ALL OTHER TYPES
COTTER SPRING
LOCKING NUTS
DISPLACER SPUD
COTTER SPRING
DISPLACER ROD
If an extension is used between the displacer spud
and the displacer stem end piece, make sure the
nuts are tight at each end of the displacer stem
extension. Install and tighten suitable bolting or cap
screws in the flanged connection to complete the
installation.
If a stillwell is required (figure 7), the displacer must
be attached to the displacer rod from inside the
vessel. Connect the displacer as shown in figure 8,
locking the assembly with the cotter spring provided.
If a stillwell is not required, the displacer can be
attached to the displacer rod before mounting the
sensor to the vessel connection. The displacer may
then be swung out horizontally for insertion into the
vessel. However, once the sensor is installed and
the displacer drops to a vertical position, the
displacer may not be capable of being withdrawn for
servicing later. Be sure there is another access to
the displacer to permit swinging it to a horizontal
position or to permit disconnecting it from the
displacer rod.
8
Top-Mounted Sensor
Figure 7 shows the installation of a top-mounted
cageless sensor. The displacer may be attached to
the displacer rod before installing the sensor on the
vessel. Where the displacer diameter is small
enough, it may be desirable to install a long or
sectionalized displacer through the sensor head
access hole after the sensor is installed on the
vessel. Connect the displacer as shown in figure 8,
locking the assembly with the cotter springs
provided. If a stem is used between the displacer as
shown in figure 8, lock the assembly with the cotter
springs provided. If a stem is used between the
displacer spud and the stem end piece, make sure
Instruction Manual
Form 1446
November 2006
2502 Series Controllers
the nuts are tight at each end of the stem. Install and
tighten suitable cap screws in the flanged connection
to complete the installation.
Regulator Supply Pressure
WARNING
Do not overpressurize any system
component. Personal injury or
property damage may occur due to
sudden pressure release or explosion.
To avoid damage, provide suitable
pressure-relieving or pressure limiting
devices if supply pressure can exceed
the maximum supply pressure listed in
table 1.
Personal injury or property damage
may occur from an uncontrolled
process if the supply medium is not
clean, dry, oil-free, or non-corrosive
gas. While use and regular
maintenance of a filter that removes
particles larger than 40 microns in
diameter will suffice in most
applications, check with an Emerson
Process Management field office and
industry instrument air quality
standards for used with corrosive gas
or if you are unsure about the proper
amount or method of air filtration or
filter maintenance.
Standard 2502 Series controllers come complete
with supply and output pressure gauges and an
integrally mounted Type 67CFR regulator to reduce
supply pressure from a maximum of 17.3 bar (250
psig) to the 1.4 or 2.4 bar (20 or 35 psig) required.
This regulator has built-in relief and a standard
40-micron to remove particles from the supply
source.
The output pressure connection is on the back of the
controller case (figure 3). Pipe the supply pressure
to the in connection of the regulator mounted to the
case back. Provide a clean, dry, and noncorrosive
air or gas supply to the controller as follows:
After pressure connections have been made, turn on
the supply pressure and check all connections for
leaks.
Prestartup Checks
WARNING
The following procedure requires
taking the controller out of service. To
avoid personal injury and property
damage caused by an uncontrolled
process, provide some temporary
means of control for the process
before taking the controller out of
service.
Adjustment locations are shown in figure 9 unless
otherwise indicted. When performing the checks
open loop conditions must exist. To obtain open-loop
conditions:
D make sure there is no process flow through the
final control element, or
D disconnect the controller output signal line and
plug the output connection.
During startup, it is necessary to change process
levels to position the displacer from its maximum to
its minimum range of operations. Provide a means to
change the process level or interface. If the process
variable cannot be varied sufficiently, follow the
instructions in the Calibration section to simulate the
process variable changes required for these checks.
Make sure that the RAISE LEVEL dial on the
controller is mounted with the correct side facing out.
The dial is printed on both sides with the arrow on
one side pointing to the left and the arrow on the
other side pointing to the right. Figure 9 shows the
dial arrow positioned for a sensor that is mounted to
the left of the controller; the arrow points to the left. If
the sensor is to the right of the controller, remove the
two mounting screws, turn the dial over so the arrow
points to the right, then reinstall the mounting
screws.
On a controller with optional level indicator assembly
the travel indicator plate is printed on both sides. If
the sensor is to the left of the controller (right-hand
mounting), use the side of the plate that has the
arrow pointing to the left. If displacer is to right of
controller (left-hand mounting), use the side of the
plate that has the arrow pointing to the right.
9
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