Building Control System(Field Sensors)
Section:Field Sensors
Field Sensors- Guide Specifications
2.1.5FIELD SENSORS
2.1.5.1Space Temperature Sensors
Space Temperature Sensors shall be 5,000 or 10,000 ohm thermistors with wall plate adapter and blank cover assembly. The sensor shall include an integral occupancy override button, and shall also include a RJ11 communications port. Temperature Sensors shall include space temperature adjustment slides where shown on theplans.The space Temperature Sensors shall be mounted approximately 60” above the floor.
2.1.5.2Duct Temperature Sensors
Duct Temperature Sensors shall be 1000 ohm averaging RTD’s, or 10,000 ohm averaging thermistors. Single point sensors shall be 5,000 ohm or 10,000 ohm thermistors.
2.1.5.3Outside Air Sensor
Outside Air Sensor shall be 5,000 or 10,000 ohm thermistor, with integral PVChousing and ½” NPT conduit connector.
Sensor shall not be located in direct sunlight, or where influenced by exhaust air.
2.1.5.4Water Temperature Sensors
Water Temperature Sensors shall be well mounted 5.000 or 10,000 ohm thermistors, or 1,000 ohm RTD’s.Locate as shown on the plans, and provide extended neck wells where applicable on insulated pipes.
Changeover thermostats shall be 10,000 ohm strap on thermistors with flexible copper plate and screw clamp for externally mounting on the pipe.
2.1.5.5Current to Pressure Transducers
Current to Pressure Transducers shall convert the 4 to 20ma analog output signal from the controller into a 3-15 PSI pneumatic output. It shall contain a 0-30 PSI manifold gauge that indicates the actual output air pressure. LED’s shall be provided to indicate power, fill or bleed status. It shall provide for minimal air consumption and feedback to the Field Installed Controller (FIC) module as to the actual output air pressure.
2.1.5.6Flow Sensors
Flow Measuring Sensors shall be complete with safety shut-off valves and all necessary connections. Flow sensors shall generate a 4-20ma proportional signal.
2.1.5.7Status Indication
Status indication for fans and pumps shall be provided by a current sensing device. The device shall be installed at the motor starter or motor to provide load indication. The device shall consist of a current transformer, a solid state current sensing circuit with adjustable trip point, and a solid state or contact switch. A red light emittingdiode (LED) shall indicate the ON OFF status of the unit. The switch shall provide a solid state or N.O. contact for wiring back to the Field Installed Controller.
2.1.5.8Filter / Status Switch
Filter Switch shall be a differential pressure type, adjustable across the range of the device, with a single pole double throw switch. The range shall be .05 to 2” water column.
2.1.5.9High Temperature Detection Thermostat
High Temperature Detection Thermostats shall be provided to stop each air handling system as indicated and shall be of the manual reset type with sensing element arranged to insert into duct or casing and shall be set for 165F. The device shall have double pole, NO, NC contacts for supply fan shutdown and remote alarming.
2.1.5.10Low Temperature Detection Thermostat
Low Temperature Detection Thermostats shall be provided to stop each air handling system as indicated and shall be of the manual reset type unless otherwise specified with sensing element not less than 20 feet long. Any one-foot of the sensing element, when subjected to temperatures below its setpoint, shall actuate the thermostatswitch regardless of temperature being sensed by the remainder of the element. The device shall have double pole, NO, NC contacts for supply fan shutdown and remote alarming. If alarming is not required, the device shall have a single pole, NC contact.
2.1.5.11Duct Relative Humidity Sensor
Duct Relative Humidity Sensors shall have a range of 0-100% RH. The sensors shall be electronic type. The measuring accuracy shall be 3% over the range of thedevice.
2.1.5.12Space Relative Humidity Sensor
Space Relative Humidity Sensors shall have a range of 0-100% RH and be provided with wall plate adapter and blank cover. The sensors shall be electronic type. The measuring accuracy shall be 3% over the range of the device. Space RH sensors shall be mounted 60” above the floor.
2.1.5.13Space CO2 Sensor with Temperature Sensor
The wall mounted combination sensors shall contain a space temperature sensor and Carbon Dioxide (CO2) sensor in a single, decorative housing. The CO2 sensor shall use single-beam absorption infrared diffusion technology, and shall haveintegral programming to perform automatic baseline calibration without user interface. The recommended manual recalibration period shall not be less than five years.The CO2 range shall be 0-2000 PPM with analog outputs of 4-20 ma or 0-10 v. the power source shall be 18-30VAC, 50/60 Hz. The accuracy shall be +/- 100 PPM at 60-90F. The sensor shall include an integral occupancy override button, a set pointadjustment potentiometer, and an RJ14 communication port.Sensor shall be located as shown on the plans and mounted approximately 60” above the floor.
2.1.5.14Duct CO2 Sensor
The Carbon Dioxide (CO2) sensor for duct mounting applications shall be use single or dual beam absorption infrared diffusion technology, and shall have integral programming to perform automatic baseline calibration without user interface. The recommended manual recalibration period shall not be less than five years. The CO2 sensor shall be mounted in an aspirator box that mounts directly to the duct. The aspirator box shall be equipped with an induction tube to direct a side-stream of air from the duct through the CO2 sensor. A hinged, clear access door shall be installed on the front of the aspirator box to permit access to the sensor and to permit viewing the sensor without opening the door.The CO2 range shall be 0-2000 PPM withanalog outputs of 4-20 ma or 0-10 volt. The power source shall be 18-30VAC, 50/60 Hz. The accuracy shall be +/- 50ppm at 60-90F. Sensor shall be located as shown on the plans.
2.1.5.15Start/Stop and Status Relays
Start/Stop and Status Relays shall be designed to plug into a screw terminal-mounting socket. Relays shall be single pole, or double pole as required with double throw contacts rated for required duty.