ELECTRIC AND PNEUMATIC CONTROL COMPONENTS FOR IAS

This article is about general and technical requirements for Electrical and Pneumatic Control Components used in Integrated Automation System or Building Automation System.

ELECTRIC AND PNEUMATIC CONTROL COMPONENTS FOR IAS

  • ELECTRIC CONTROL COMPONENTS <Modify as required to match project design>

    • Limit Switches (LS): Limit switches shall be UL listed, SPDT or DPDT type, with adjustable trim arm.  <Limit switches shall be as manufactured by Square D, Allen Bradley> or approved equal.
    • Electric Solenoid-Operated Pneumatic Valves (EP): EP valves shall be rated for a minimum of 1.5 times their maximum operating static and differential pressure.  Valves shall be ported 2-way, 3-way, or 4-way and shall be normally closed or open as required by the application.  EPs shall be sized for minimum pressure drop, and shall be UL and CSA listed.  Furnish and install gauges on all inputs of EPs.  Furnish an adjustable air pressure regulator on input side of solenoid valves serving actuators operating at greater than 30 psig.
      • Coil Enclosure: Indoors shall be NEMA 1, Outdoors shall be NEMA 3, 4, 7, 9.
      • Fluid Temperature Rating: Valves for compressed air and cold water service shall have 150 degrees F (66 degrees C) minimum rating.  Valves for hot water or steam service shall have fluid temperature rating higher than the maximum expected fluid temperature.
      • Acceptable Manufacturers: <Confirm list>
        1. Honeywell
        2. ASCO
        3. Approved equal
      • Coil Rating: EP valves shall have appropriate voltage coil rated for the application (i.e., 24 VAC, 120 VAC, 24 VDC, etc.).
    • Low Temperature Detector (‘Freezestat’) (FZ): Low temperature detector shall consist of a ‘cold spot’ element which responds only to the lowest temperature along any one foot of entire element, minimum bulb size of 1/8 inches x 20 feet (3.2mm x 6.1m), junction box for wiring connections and gasket to prevent air leakage or vibration noise.  Temperature range 15 to 55 degrees F (-9.4 to 12.8 degrees C), factory set at 38 degrees
      1. Provide one low limit thermostat for each 20 square feet or fraction thereof of coil surface area
      2. Provide Manual reset
      3. Sensor shall be DPDT 120/240 volts AC, rated at 10 Amps at 120 volts full load.(4 wire, 2 circuit)
    • High Temperature Detectors (‘Firestat’) (FS): High temperature detector shall consist of 3-pole contacts, a single point sensor, junction box for wiring connections and gasket to prevent air leakage of vibration noise, triple-pole, with manual reset.  Temperature range 25 to 215 degrees F (-4 to 102 degrees C).
    • Surface-Mounted Thermostat: Surface-mounted thermostat shall consist of SPDT contacts, operating temperature range of 50 to 150 degrees F (10 to 65 degrees C), and a minimum 10 degrees F fixed setpoint differential.
    • Low Voltage Wall Thermostat: Wall-mounted thermostat shall consist of SPDT sealed contacts, operating temperature range of 50 to 90 degrees F (10 to 32 degrees C), switch rating of 24 VAC (30 VAC maximum), and both manual and automatic fan operation in both the heat and cool modes.
    • Control Relays General:
      1. Relays other than those associated with digital output cards shall be general purpose, enclosed plug-in type with 8-pin octal plug and protected by a heat and shock resistant duct cover. Number of contacts and operational function shall be as required.
      2. Solid State Relays (SSR): Input/output isolation shall be greater than l0E9 ohms with a breakdown voltage of 1500V root mean square or greater at 60 Hz. The contact life shall be 10 x 10 E6 operations or greater. The ambient temperature range of SSRs shall be -20 to +140° Input impedance shall not be less than 500 ohms. Relays shall be rated for the application. Operating and release time shall be for 100 milliseconds or less. Transient suppression shall be provided as an integral part of the relay.
      3. Contactors: Contactors shall be of the single coil, electrically operated, mechanically held type. Positive locking shall be obtained without the use of hooks, latches, or semi-permanent magnets. Contractor shall be double-break-silver-to-silver type protected by arcing contacts. The number of contacts and rating shall be selected for the application. Operating and release times shall be 100 milliseconds or less. Contactors shall be equipped with coil transient suppression devices.
    • Control Relays: All control relays shall be UL listed, with contacts rated for the application, and mounted in minimum NEMA 1 enclosure for indoor locations, NEMA 4 for outdoor locations.
      1. Control relays for use on electrical systems of 120 volts or less shall have, as a minimum, the following:
        1. AC coil pull-in voltage range of +10 percent, -15 percent or nominal voltage.
        2. Coil sealed volt-amperes (VA) not greater than four (4) VA.
        3. Silver cadmium Form C (SPDT) contacts in a dustproof enclosure, with 8 or 11 pin type plug.
        4. Pilot light indication of power-to-coil and coil retainer clips.
        5. Coil rated for 50 and 60 Hz service.
        6. Material: Gold Flash
        7. Rating 10 amps at 120-277 VAC
        8. Provide HOA switch except in smoke control applications.
        9. Acceptable Manufacturers: <Confirm list>
          1. Honeywell
          2. Potter Brumfield
          3. Approved equal
      1. Relays used for across-the-line control (start/stop) of 120V motors, 1/4 horsepower, and 1/3 horsepower, shall be rated to break minimum 10 Amps inductive load. Relays shall be <IDEC or approved equal>.
      2. Relays used for stop/start control shall have low voltage coils (30 VAC or less), and shall be provided with transient and surge suppression devices at the controller interface.
      3. All safety circuits shall be installed to operate individual interposing relays located in the associated equipment control panel. Each safety device (i.e. Freezestat, DP safety, smoke detector, firestat, etc.) wiring circuit shall be installed with individual homeruns back to the associated control panel.  <See IAS control drawings for details>.
    • General Purpose Power Contactors: NEMA ICS 2, AC general-purpose magnetic contactor. ANSI/NEMA ICS 6, NEMA 1 enclosure. Manufacturer shall be <Square ‘D’, Cutler-Hammer, Westinghouse, or approved equal>.
    • Control Transformers: Furnish and install control transformers as required.  Control transformers shall be machine tool type, and shall be US and CSA listed.  Primary and secondary sides shall have replaceable fuses in accordance with the NEC.  Transformer shall be properly sized for application, and mounted in minimum NEMA 1 enclosure.
      • Transformers shall be manufactured by <Westinghouse, Square ‘D’, Jefferson, or approved equal>.
    • Time Delay Relays (TDR): TDRs shall be capable of on or off delayed functions, with adjustable timing periods, and cycle timing light.  Contacts shall be rated for the application with a minimum of two (2) sets of Form C contacts, enclosed in a NEMA 1 enclosure.
      • TDRs shall have silver cadmium contacts with a minimum life span rating of one million operations. TDRs shall have solid state, plug-in type coils with transient suppression devices.
      • TDRs shall be UL and CSA listed, Crouzet type.
    • Electric Push Button Switch: Switch shall be momentary contact, oil tight, push button, with number of N.O. and/or N.C. contacts as required.  Contacts shall be snap-action type, and rated for minimum 120 VAC operation.  Switch shall be 800T type, as manufactured by <Allen Bradley or approved equal>.
    • Pilot Light: Panel-mounted pilot light shall be NEMA ICS 2 oil tight, transformer type, with screw terminals, push-to-test unit, LED type, rated for 120 VAC.  Unit shall be 800T type, as manufactured by <Allen-Bradley or approved equal>.
    • Alarm Horn: Panel-mounted audible alarm horn shall be continuous tone, 120 VAC Sonalert solid-state electronic signal, as manufactured by <Mallory or approved equal>.
    • Electric Selector Switch (SS): Switch shall be maintained contact, NEMA ICS 2, oil-tight selector switch with contact arrangement, as required.  Contacts shall be rated for minimum 120 VAC operation.  Switch shall be 800T type, as manufactured by <Allen-Bradley or approved equal>.

  • PNEUMATIC CONTROL COMPONENTS <Modify as required to match project design>

    1. Analog Pressure Gauges: Gauges shall be pneumatic type, minimum 1-1/2 inches (38 mm) in diameter, with white face and black numerals.  Surface-mounted gauges shall have chrome plated trim and be a minimum of 2-1/2 inches (64 mm) in diameter.
    2. Pneumatic Actuated Pressure Switches (PE) (for 30 psig max pressure control systems): Pressure ranges and sensitivity of PEs shall match control system sequence of operation.  Switch operation shall be externally adjustable over the operating pressure range (nominal 0-20 psig, 0 to 138 KPa).  PE switches shall be SPDT type, rated for the particular application, and shall be UL listed.  <PE shall be as manufactured by Penn.>
    3. Pilot Positioners: Operating span adjustment range is from 3 to 15 psi (21 to 104 kPa), or as required for the actuator being served. Positioner shall be furnished with zero and span adjustments and a mounting bracket for attachment directly to the actuator.
    4. Pneumatic Valve/Damper Position Indicator: Potentiometer mounted in enclosure with adjustable crank-arm assembly connected to damper to transmit 0 to 100 percent valve/damper travel.

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