2.01 General
A. FLOW MEASUREMENT
Metering shall be provided to measure consumption of the main irrigation water use for each application
rate in gpm and a pulse signal that shall be wired back to the CCU. The pulse signal shall be compatible with the CCU and Satellite Controller signal specifications.
B. LOCATION OF METER
All meters shall be installed within the building, free from exposure to freezing. The meter shall to be acces-sible for ease of reading.
C. STRAINERS & TEST PORT
All meters shall be provided with Metron-Farnier strainers upstream of the meter. Test ports shall be provided downstream of the meter on installations of meters 4” and larger. The test port shall be equipped with a full port ball valve and a 2 _” M hose tread test port outlet, located so as to allow the connection of a fire hose.
D. MASTER IRRIGATION VALVE
Each building or area shall have a master irrigation valve that is used to prevent excessive irrigation water flow due to a line break or malfunction of the Satellite Controller. The valve shall fail closed upon loss of electrical power. The master valve shall operate with 24 volts ac. An isolation relay shall be installed in the panel enclosure for each Controller that operates the master valve. The master valve power supply shall be from a 120 volt ac/24 volt ac transformer fused on both sides. The transformer shall be installed in the Controller enclosure. The master valve body and port shall be sized to so that it does not restrict irrigation flow for the building or area. The master valve shall be closed by the irrigation control system upon detection of excessive flow rate. The valve shall be a bronze body with flanged ends or threaded ends rated at 150 lbs WOG and approved by the Massachusetts plumbing code.
E. MASTER VALVE INSTALLATION
The master valve shall be installed within the building, free from exposure to freezing. The contractor shall provide unions at the inlet and outlet of the master valve for threaded end valves. The valve electrical enclo-sure shall be NEMA 4. Manual shutoff ball valves shall be furnished upstream and downstream of the master valve. The shutoff valves shall be a bronze body with flanged ends or threaded ends rated at 150 lbs WOG and approved by the Massachusetts plumbing code.
F. BOOSTER PUMP APPLICATIONS
If the building or area requires a booster pump due to low supply pressure, the irrigation control system shall provide automatic operation of the booster pump motor starter. The booster pump MCC (motor starter) shall be provided with a hand-off-auto control switch. The Landscaping contractor shall wire the auto position to the associated Satellite Controller or CCU to start or stop the booster pump when there is a demand for irrigation water. Anytime the master valve is closed, the booster pump shall be stopped. The booster pump shall be started upon demand for irrigation. If adequate flow is not detected by the flow meter 60 seconds after the pump is started, the pump shall be stopped and a low flow failure alarm shall be initiated to the Central Controller head-end. The booster pump shall be stopped whenever there is no flow demand. The irrigation control system shall include an “ice cube” isolation relay with dry contacts rated at 10 amps to interface with the MCC 120 volt ac pilot circuit. The relay shall be an Allen-Bradley 700 HA series with DPDT contacts or Owner approved equal. The relay shall be located in the CCU or Satellite Controller enclosure.
G. IRRIGATION STATION ZONE VALVES
Irrigation station zone valves shall be installed for each grouping of sprinkler heads. Irrigation station zone valves shall fail closed on loss of power. The zone valves shall be wired back to the Satellite Controller.
Irrigation valves located underground shall be installed in a protective box with access at the ground surface.
3 CCU and SATELLITE CONTROLLER PANEL ENCLOSURES 3.01 General
A. REQUIREMENTS
Enclosures shall be provided to house the Satellite Controllers and CCUs and miscellaneous devices. The Landscaping Contractor may elect to furnish a common enclosure for both Satellite Controllers and CCUs if there is adequate space. The enclosure shall be wall mounted using galvanized steel Unistrut or equal bracing. The enclosure shall be sized to contain the CCU, Satellite Controller, modems, surge suppressors, transformers, relays, terminal blocks, fuses, wire trough, special cables, etc. with 6 inches space between equipment and the exterior enclosure surface. Each enclosure shall be provided with a full steel back panel for mounting all equipment within the enclosure. Enclosures shall be rated NEMA 4 steel for indoor installation and rated NEMA 4X fiberglass for outdoor installation. Enclosures shall be Hoffman or approved equal. The enclosure front door shall be hinged with a 3-point latch mechanism. A hasp hinge for a padlock shall be provided to secure the enclosure. MIT Grounds Group will provide padlocks.
B. POWER DISTRIBUTION and WIRING
Incoming 120 volt ac power shall be wired to a power terminal block for L1, L2, and Ground. L1 power shall be distributed to fuse disconnects with blown fuse indicators (Allen-Bradley 1492-H series or approved equal) for each user. Install an Intermatic AG2401 or approved equal surge suppressor for the incoming ac power line. In addition, all other power supplies at 24 volts ac and 24 volts dc shall include fused disconnects. 120 volt ac wiring shall be L1-Black, L2-White, Ground-Green. Single conductor wiring within panels shall be stranded copper type MTW, with wire gauge sized for the ampacity in accordance with National Electric Code. 24 volt ac wiring shall be red. Dc wiring shall be blue (positive) and blue with a white stripe (negative).
Analog signal cable shall be stranded, 20 gauge minimum, shielded twisted pairs with continuous foil shield and copper drain wire. Wire and cable shall be labeled with permanent wire markers as shown on the shop drawings. Wires shall be run in covered wire trough (Panduit or equal) within the enclosure. Wire trough shall be no more than 50% full after the irrigation system is completely installed. Terminal blocks shall be furnished for all field wiring for irrigation valves, communications, and sensors. Terminal blocks for each voltage level and signal type shall be separated. Terminal blocks shall be rated for the maximum load ampacity. Terminal blocks shall be uniquely labeled and each terminal shall be labeled in accordance with the shop drawings.
Use “finger safe” type terminal blocks similar to Allen-Bradley W series. At least 10% spare terminals and fuse disconnects shall be provided after system is completely installed.
C. LOCATION OF ENCLOSURE
The enclosure location shall be approved by the MIT Grounds Group prior to installation. Enclosures shall be located indoors wherever practical. Enclosure shall be wall mounted with adequate door swing. Do not locate panels in any manner to violate the NEC requirements. The height of the panel shall be approximately 4 foot 6 inches to the centerline of the panel above the finished floor. Outdoor CCU and Satellite Controllers may be installed in NEMA 4X stainless steel pedestal enclosures if indoor installation is not possible.
D. CONDUIT ENTRANCE
Conduits shall enter through the bottom of the enclosure whenever practical. Conduit entrance shall be weatherproof. A plastic bushing shall be provided at each conduit entrance. Conduits and wiring shall be separated according to voltage level and type. Conduits and wiring shall be run separately for 120 volts ac, 24 volts ac, and 24 volts dc.
A. Furnish Rain Bird Maxicom Cluster Control Units Model CCU-6 or CCU-28 as required for the size of the Landscaping project building or area. A CCU-6 will serve up to 6 Satellite Controllers. A CCU-28 will serve up to 28 Satellite Controllers.
B. The CCU shall be attached to the back panel of the NEMA enclosure as specified hereinbefore.
C. Installation and wiring of the CCU shall be in accordance with the vendor’s recommendations. Provide #6 AWG copper ground in accordance with vendor recommendations.
5 SATELLITE CONTROLLERS