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Section 1
Model 581A Differential 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)
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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
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Additional 2% is applicable near the switch setpoints (±10% span).
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neering Report 9A-CR3-580A-29.
Design Basis Event (DBE) Performance Error
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(% of calibrated span):
Radiation (1 x 10
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Rads) ................ ±10%
Seismic (12.5 Gs):
During Event ................................... ±10%
Following Event .............................. ±5%
Harsh Environment (≤ 200°F):
During Event ................................... ±10%
Following Event .............................. ±10%
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Includes the cumulative effect of accelerated aging.