ITT BARTON 581A User manual

BARTON®NUCLEAR MODEL 581A
DIFFERENTIAL PRESSURE
SWITCH
User Manual
Part No. 9A-C10766, Rev. 01
October 2011
Model 581A-0
Contents
Safety............................................................................................................ 2
Section 1—Introduction................................................................................. 3
General ......................................................................................................... 3
Wiring ........................................................................................................ 5
Differential Pressure Unit .......................................................................... 5
............................................................................................... 6
General:..................................................................................................... 6
............................................................................... 6
......................................................................... 7
.............................................................................. 7
Section 2—Installation................................................................................... 9
Mounting/Piping/DPU Installation ................................................................. 9
Electrical Connection .................................................................................... 9
Switch Use.................................................................................................... 9
Startup ........................................................................................................ 10
Switch Wiring .............................................................................................. 10
Section 3—Maintenance and Calibration....................................................11
Tools.............................................................................................................11
Bezel/Lens Assembly or Cover Installation and Removal........................... 12
Pointer Installation and Removal ................................................................ 13
Pointer Installation .................................................................................. 13
Pointer Removal...................................................................................... 14
Scale Plate Installation and Removal ......................................................... 14
Indicator Calibration.................................................................................... 15
Drive Arm Tightness Test......................................................................... 17
Drive Arm Stop Adjustment ..................................................................... 17
Switch Calibration ..................................................................................... 17
Calibration Setup..................................................................................... 18
Linkage Calibration Procedure ............................................................... 18
Changing Switch Set Point ........................................................................ 20
................................................................................. 20
Best Practices for Set Points................................................................... 20
Changing Set Point of an In-Service Instrument ..................................... 20
Changing Set Point of an Out-of-Service Instrument .............................. 21
Range Changes ...................................................................................... 22
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Model 581A Dierential Pressure Switch Section 1
Section 1—Introduction
General
The 581A Differential Pressure Switch actuates single or dual signal circuits
-
nected to the process or vessel by tubing or piping. Changes in differential
pressure (DP) at the DPU produce a mechanical output which moves a pointer
and switch actuation controls.
and low-pressure sides of a primary device in the process run. Normally the
For liquid level measurement applications, the instrument is connected to
measure changes in differential pressure caused by variations in hydrostatic
pressures of the liquid in a tank.
The 581A switch is available in three model variations:
• Indicating Switch (Model 581A-0). This model, shown on the manual
cover, has a thick tempered plate glass lens and provides a visual indica-
tion of the difference in the two monitored pressures.
• Blind Switch (Model 581A-2).This model has a solid metal cover and
provides no visual indication of differential pressure.
• Blind Switch with Internal Indicator. Unlike the indicating model with
the glass lens, there is no externally visible indicator. However, internally,
components are the same as in Model 581A-0. With the cover removed, a
user can use the internal indicator to determine DPU input pressure when
making adjustments to the switch setpoints.
The Model 581A uses two independently adjustable single-pole double-throw
(SPDT) snap-acting switches that are rated for high temperatures. Both sides
of the switchesare wired, enabling the switchesto serve both normally-open
and normally-closed applications. The direct-set switch contactsare adjustable
overa scale range of10-90%nominal. Switchesand all adjustmentsare read-
ily accessible when the coveris removed (see Figures 1.1and 1.2,page 4).
IEEE 344-1975, IEEE 381-1977and NUREG 0588, Rev. 1 for either Func-
tional and/or Pressure Boundary Integrity service in limited harsh environ-
ment applications.
The switch case is drawn stainless steel with a sealed glass header for the
electrical interface with the switches. No additional conduit seals are required
to ensure the integrity of the instrument.

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Section 1 Model 581A Dierential Pressure Switch
Left Switch Right Switch
Pointer
Left Switch
Lock Screw
Plunger Screw
Actuating Cam
Left Switch
Adjustment
Assembly*
Switch Adjust Linkage
Plunger Screw
Right Switch
Lock Screw
Drive Arm
Stop Bracket
Movement Assembly
Terminal Strip
Switch Adjust Linkage
Right Switch
Adjustment
Assembly*
Range Adjust
* Switch Adjustment Assembly includes crank, index shaft, and index pointer.
Figure 1.1—581A (with indicator), internal components
Left Switch Right Switch
Left Switch
Lock Screw
Plunger Screw
Actuating Cam
Left Switch
Adjustment
Assembly*
Switch Adjust Linkage
Plunger Screw
Right Switch
Lock Screw
Terminal Strip
Switch Adjust Linkage
Right Switch
Adjustment
Assembly*
Cam Actuator
* Switch Adjustment Assembly includes crank, index shaft, and index pointer.
Figure 1.2—581A (without indicator), internal components
The cam rotates counterclockwise with increased pressure. In Figure 1.3, page
5, the LOW switch (typically set to alarm at decreasing pressure) is set at 25%
differential pressure while the HIGH switch (typically set to alarm at increas-
ing pressure) is set at 75% differential pressure.

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Model 581A Dierential Pressure Switch Section 1
1000
50
Zero DP
1000
50
Maximum DP
DER
Y OLLE W
B UL E
B CAL K
NEERG
WHITE
1000
50
SW I T C H "A"
(LEFT)
SW I T C H "B"
(RIGHT)
CAM
TERM I NAL
BLO C K I N
CAS E
BO T H S W I TCHES RELAX ED
SWITCH
PLUNGER
SC REW
Mid-point DP
HIGHLOW
SW I T C H "A" AC T UAT ED/S WITCH "B" RELAX ED
SW I T C H "A" RELAX ED/SW I T CH "B" AC TUAT ED
SWITCH CLOSED
CONTACTS
OPEN
CONTACTS
GREEN/WHITE GREEN/BLACK
A (LEFT)
B (RIGHT)
YELLOW/BLUE YELLOW/RED
SWITCH CLOSED
CONTACTS
OPEN
CONTACTS
GREEN/WHITE GREEN/BLACK
A (LEFT)
B (RIGHT)
YELLOW/RED YELLOW/BLUE
SWITCH CLOSED
CONTACTS
OPEN
CONTACTS
GREEN/WHITEGREEN/BLACK
A (LEFT)
B (RIGHT)
YELLOW/BLUE YELLOW/RED
SW I T C H "A"
(LEFT)
SW I T C H "B"
(RIGHT)
SW I T C H "A"
(LEFT)
SW I T C H "B"
(RIGHT)
Notes:
1. CAM ROTATES COUNTER-CLOCKWISE WITH INCREASED DIFFERENTIAL PRESSURE
2. EACH SWITCH MAY BE SET AT ANY POINT FROM 10% TO 90% OF DP RANGE
3. WIRES: No. 22 AWG (Internal) and No. 18 AWG (External)
Figure 1.3—Switch wiring connections and actuation example
Wiring
Each switch is wired internally to a glass-sealed header using No. 22 AWG
®) insulated wire for radiation service per
IEEE Standard 393-1974. Externally, from the header, permanently color
coded No. 18 AWG Tefzel®wires exit through a female conduit connection.
Differential Pressure Unit
For detailed information on the Model 199 DPU, see Appendix A.

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Section 1 Model 581A Dierential Pressure Switch
General:
Actuating Unit (DPU) ...................... Model 199 DPU
Dial Size ......................................... 6 inches (150 mm)
Service Conditions (Normal)........... 40°F (4.4°C) to +180°F (+57.2°C) @ <90% R.H.
Switch Repeatability ....................... ±1% of calibrated span
Switch Set-point Range.................. 10 to 90% of calibrated span
Switch Deadband ........................... ±10% of calibrated span (maximum)
Switch Type .................................... Mechanical, Snap-Acting; both switches are SPDT
Activation........................................ Increasing or decreasing scale
Switch Contact Rating:
5.0 Amps @ 125 VAC
5.0 Amps @ 250 VAC
3.0 Amps @ 30 VDC (resistive)
1.0 Amp @ 30 VDC (inductive w/arc suppression)
0.4 Amp @ 125 VDC (resistive)
0.2 Amp @ 125 VDC (inductive w/arc suppression)
Input Range.................................... 0-10" WC to 0-115 psid
Indicator Accuracy .......................... ±2.0% of calibrated span (for ranges to 400 psid)1
Indicator Repeatability.................... ±0.5% of calibrated span
Safe Working Pressure................... 3000 psig
Maximum Overrange...................... To safe working pressure
Process Connections...................... 1/4" NPT top and bottom
1/2" NPT top and 1/4" NPT bottom
Electrical Connections.................... Female, 3/4" NPT, 20 ft., color-coded Tefzel®
insulated 18 AWG wire (40 ft. leads available by
special order)
Torque Tube Rotation ..................... 8° (nominal)
Accuracy of Repeatability............... ±0.5% of calibrated span
1Additional 2% is applicable near the switch setpoints (±10% span).
-
neering Report 9A-CR3-580A-29.
Design Basis Event (DBE) Performance Error1(% of calibrated span):
Radiation (1 x 107Rads) ................ ±10%
Seismic (12.5 Gs):
During Event................................... ±10%
Following Event .............................. ±5%
Harsh Environment (≤ 200°F):
During Event................................... ±10%
Following Event .............................. ±10%
1Includes the cumulative effect of accelerated aging.

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Model 581A Dierential Pressure Switch Section 1
-
cation testing, which found the devices suitable for functional service in a
limited harsh environment. The service conditions associated with the limited
• 1normal conditions of 104°F and 0 psig
• Radiation exposure to 1 x 107Rads (TID)
• 85 days @maximum DBE conditions of 200°F, 10 psig ambient pressure
and ≥ 95% R.H.
•
– OBE @ 6.25 Gs (series of 5)
– SSE @ 12.5 Gs
– 5% critical damping
– No resonance in frequencies below 33 Hz
• Mechanical aging included:
– 25,000 pressure cycles during accelerated aging
– 12,500 electrical cycles during accelerated aging
– Vibration cycling using 0.2 G sinusoidal sweeps over the 1 to 200
Hz range at 1.0 octave/min.
1
governed by factors such as environmental temperature, radiation exposure, and activa-
tion energy.
Storage per ANSI N45.2.2-1978 Level B at 70°F (21°C) ±20°F (±11°C) in
factory sealed package for 2.5 years maximum will not affect installed service
life.

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Section 1 Model 581A Dierential Pressure Switch

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Model 581A Dierential Pressure Switch Section 2
Section 2—Installation
The instrument should be inspected at time of unpacking to detect any dam-
age that may have occurred during shipment.
IMPORTANT: The DPU was checked for accuracy at the factory. Do not change any of
the settings during examination or accuracy could be affected.
For applications requiring special cleaning/precautions, a polyethylene bag
is used to protect the instrument from contamination. This bag should be
removed only under conditions of extreme cleanliness.
Mounting/Piping/DPU Installation
Mount the instrument with four 5/16" (8mm) bolts, Grade 5 or greater,
torqued to 17 ft/lbs (see Figure 7.1). Mounting structures should be designed
Response spectra at mounting surface of the instrument shall not exceed those
conduit shall be supported by the same mounting as the DP instrument base
in order to minimize relative motion of the DP instrument and connections.
Dimensional drawings are provided in Section 5, page 32.
See Appendix A for Model 199 DPU installation and maintenance informa-
tion.
Electrical Connection
Units are supplied with dual alarm switches. The direct-set switch contacts
are adjustable over 10% to 90% of the scale range.
The high switch and low switch set point adjustment procedures are covered
in Changing Switch Set Point, page 20.
For physical location of switches, see Figures 1.1 and 1.2, page 4.
Switch Use
temperature, humidity, airborne contamination, vibration, amount of plunger
travel, cycling rate, and rate of plunger travel (and others), as well as by the
electrical (circuit) characteristics.
IMPORTANT: Arc suppression for inductive loads will prolong the life of the switch
contacts.

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Section 2 Model 581A Dierential Pressure Switch
Startup
For startup procedures, warnings, and other information, refer to Appendix A.
IMPORTANT: To ensure the unit calibration is within factory-set calibration tolerances,
perform the Calibration Check procedure on page 12.
Switch Wiring
IMPORTANT: Figure 2.1 shows switch contacts in the relaxed (shelf) condition, the low
switch set to trip at a position below the pointer scale position, and the
high switch set to trip at a position above the pointer scale position. NO
= Normally Open in (shelf) condition. NC = Normally Closed in (shelf)
condition. C= Common.
LOW & HIGH SPDT SWITCHES
NO NOC CNC NC
RED YELLOW BLUE
RED YELLOW BLUE
WHITE GREEN BLACK
WHITE GREEN BLACK
1 2 3 4 5 6 7 8 9 10
Figure 2.1—Low/high SPDT switch diagrams
Table 2.1—Switch Wire Color Coding
581A Current
NO C NC
Low Red Yellow Blue
High Black Green White

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Model 581A Dierential Pressure Switch Section 3
Section 3—Maintenance and Calibration
The following checks are recommended for preventive maintenance:
• Periodically inspect the alarm switch mechanism to verify that all mount-
ing screws are seated properly.
• Inspect linkage for wear.
• Inspect integrity of electrical circuits. Tighten as necessary.
When repairs are necesssary, review this section for maintenance procedures
such as bezel/lens installation and removal, pointer installation and removal,
indicator calibration, switch calibration, and switch set point changes. Refer
Figure 3.1—Model 581A adjustment controls
IMPORTANT: See Appendix A for related warning/caution notices and instructions
on DPU inspection, cleaning, service, repair, range change, and BUA
replacement. Never perform maintenance/repair on the Model 581A
differential pressure switch or DPU without reviewing all proce-
dures and warning/caution notices in Appendix A.