Sprinkler System Tutorial

Planning Check List

• Obtain static pressure and record information.
• Obtain water flow information and record.
• Draw plot plan accurately of property on graph paper.
• Indicate location of water sources to be used on graph paper.
• Select type of sprinklers to be used based on spray patterns and GPM use.
• Locate sprinklers on graph paper, marking overlapping sprays with compass.
• Establish zones with number and type heads on each zone.
• Select type and size of pipe.

Gathering Information

If using city water

• Find Your Water Pressure - Static water pressure is the pressure at your sprinkler water source when no water is being used elsewhere in your system. To measure this pressure, generally expressed in pounds per square inch (PSI, attach a pressure gauge to your outside faucet and record this value on your design form. In some communities, your local water board can inform you what static pressure you have available. Note: Make sure all water outlets, both inside and outside the house are turned off to guarantee a proper reading.
• Find Your Water Meter Size- Water meters are usually 5/8", 3/4", 3/4" or 1". You'll find this number stamped on the side of the water meter or printed on your water bill. If not, contact your local water company.
• Record information on your design form.
• Find Your Service Line Size- The service line is the water pipe running from the street to your home. To determine the size, wrap a string around the pipe and measure the string length. Use the following information to convert the string length to pipe size.
  • SIZE IN COPPER PIPE:
    • 2-1/2" string length = 3/4" copper pipe
    • 3-1/2" string length = 1" copper pipe
    • 4-1/4" string length = 1-1/4" copper pipe
  • SIZE IN PVC OR GALVANIZED PIPE:
    • 3-1/4" string length = 3/4" PVC or galvanized pipe
    • 4" string length = 1" PVC or galvanized pipe
    • 5" string length = 1-1/4" PVC or galvanized pipe
• Find Your Rate Of Water Flow The rate of water flow is expressed in gallons per minute (GPM). The easiest way to obtain this value is to follow the suggested procedure outlined below.
  • Get a measurable container, like a 5 gallon bucket, make sure no other water is running in or outside the house.
  • Turn the faucet on all the way and time how long it takes to fill the container.
    Note: If our 5 gallon container took 17.5 seconds to fill, then the number of gallons divided by the number of seconds to fill times 60 seconds = GPM (5 / 17.5 X 60 = 17.14. Round your answer to the nearest whole number.
  • Write your water capacity on the information sheet.

When using water from pump system

• Check with the pump dealer or your owner's manual to obtain the pressure and flow capacity of your pump. Your pump type, capacity and the distance you are moving the water determine these figures.
• Only after pump in-take is connected to either a well, canal or lake, place a 5 gallon bucket under the pump outlet (the pipe going to the control valve) and time how long it takes to fill it.

Plotting Diagram

• On a graph paper, draw the outside boundaries of your house, garage, walkways, driveways, shrub beds, etc. On the graph paper, one large square equals 10 feet. For larger lots, it may be necessary for one large square to equal 20 feet. It is very important that you draw everything accurately so remember to indicate the position of your water source.

Selecting Sprinkler Heads

• The selecting of sprinklers will depend upon the shape and areas to be watered and the amount of PSI and GPM available.
• A good place to start is by locating impulse or gear drive sprinklers for large areas (25' X 25' or larger) and spray heads and rotors for smaller areas.

Spacing Sprinkler Heads

• To properly position your sprinkler at the best location on the graph paper, it is suggested that you use a compass to draw the sprinkler radius shown in the performance chart.
• Spacing of sprinkler heads should be no more than 45 feet apart for impulse heads or gear drives and 12 feet for spray heads.
• When these spacing are followed, you will find that 100% overlap is achieved, which is essential for perfect watering and elimination of any dry spots.
• At this point in your design plan, you should have identified all areas to be watered, selected all types of heads needed based on spray patterns and (GPM's) established the proper positioning and spacing for all heads. This information must be completed before proceeding to the next step.

Establishing Zones

• The number of sprinkler heads used on a zone is determined by the amount of water available from your source and the water used by your sprinkler heads.
• For example, is 15 GPM is available, you could use four impact heads on each zone with each sprinkler using 3 GPM for a total of 12 GPM. If half circle heads are used and each uses 1.5 GPM, then a total of 8 sprinklers could be used on each zone.
• It is advisable to have some reserve flow available when sizing your zones to allow for flow and pressure fluctuations they may occur at different times of the day.
• Once you have noted the flow rate of each head on your graph paper, start grouping the heads by zone.
• Make sure that different type of sprinklers are not in the same zone, i.e. rotors, pop-ups, impulse, bubblers, shrub heads, etc. This is because each type of sprinkler head requires different amounts of water and pressure to perform properly.
• By mixing heads, it is possible to cause other heads in the same zone to operate poorly or not at all.
• For example, you might make the front lawn one zone with pop-ups, the front shrubbery area another zone with spray heads and the back yard a third zone with impulse sprinklers.

Choose Your Pipe

• When installing and underground sprinkler system, there are two types of pipe used, PVC ridged pipe and Polyethylene flexible pipe. Poly flexible pipe is suggested for areas that experience freezing ground.
• In choosing pipe size refer to the information given below. If in doubt, always select the next larger size pipe because larger pipe size will generally improve performance.
• A common practice is to run larger diameter pipe from your water source to your control valve, then to a central spot in the zone to be watered and then reduce pipe size in branching lines to your sprinkler heads.
• When making long pipe runs over 100 feet, use one pipe size larger in diameter to reduce pressure losses at the end of the run.
• IMPORTANT: When choosing pipe sizes, take note that your pipe fittings should be the same size or larger than the control valves to assure proper performance.
• GALLONS THROUGH PIPE
  • 0-8 GPM: use 3/4" valve, 3/4" PVC pipe or 3/4" Poly pipe
  • 9-12 GPM: use 3/4" valve, 3/4" PVC pipe or 1" Poly pipe
  • 13-20 GPM: use 1" valve, 1" PVC pipe or 1-1/4" Poly pipe
  • 21-35 GPM: use 1" valve, 1-1/4" PVC pipe or 1-1/2" Poly pipe

Zone controls

• Manual valves are either gate valves or ball valves.
• Automatic valves can be electric anti-siphon, electric solenoid (in-line) or indexing valves. The grouping of one or more valves is called a manifold. Each valve turns a group of sprinklers on and off and can be controlled manually or by an automatic timer.
• Remember to check all local codes before installing to make sure you have chosen the right valve for your system.

Automatic Timers

• An automatic timer is used to turn your sprinkler system on and off. The timer tells your valves which days to water, when to turn on, how long to water and when to shut-off.
• Single station mechanical timers generally control your system on off, days to water, and watering duration through the use of tripper pins.
• Multi-station programmable timers are basically computers which allow specific watering cycles, duration and times depending on the needs of your yard.

General Safety Information

• Follow all local electrical and safety codes, as well as the National Electrical Code (NEC) and the Occupational Safety and Health Act. (OSHA)
• Replace damaged or worn wiring cord immediately.
• Do not kink power cable and never allow the cable to come in contact with oil, grease, hot surfaces, or chemicals.
• Protect the power cable from coming in contact with sharp objects.
• Be careful when touching the exterior of an operating motor - it may be hot enough to be painful or cause injury.
• Make certain that the power source conforms to the requirements of your equipment.
• Always disconnect power source before performing any work on or near the motor or its connected load. If the power disconnect point is our-of-sight, lock it in the open position and tag it to prevent unexpected application of power. Failure to do so could result in fatal electrical shock.
• Do not handle the pump with wet hands or shock could occur. Disconnect main power before handling unit for any reason.
• Unit must be securely and adequately electrically grounded. This can be accomplished by wiring the unit to a ground metal-clad raceway system or by using a separate ground wire connected to the bare metal of the motor frame or other suitable means.

Location

• Pump can be located at the well or can be offset some distance away from the well. For best performance it should be located as close to the well as possible.
• Location can be in the basement, a pit below ground, or in a pump house above ground.
• Ventilation and drainage must be provided to prevent damage from moisture to the motor and switches.
• The pump and all piping must be protected from freezing.
• Pump and pipe line must be drained when not in use if the is any danger of freezing.

Well Conditions

• Wells should be pumped clean of all sand and foreign matter before installing the pump or damage may result to the operating parts.
• The well must be able of supplying enough water to satisfy the capacity of the pump and water needs The water level must not draw down below the maximum rated suction lift of the pump or loss of capacity and prime will result.

Suction Limitations

• Shallow well installation is satisfactory where the suction lift is less than 25 feet. Suction lift is the vertical lift plus losses due to friction loss.
• Suction lift varies depending upon elevation (altitude) and water temperature.

Piping

• Plastic or galvanized steel pipe may be used in the installation. Plastic pipe must have a minimum pressure rating of 160 PSI. Galvanized steel pipe must be in good condition free of rust and scale. Threads should be sharp, cleanly cut.
• Both suction and discharge pipe should be no smaller than the corresponding tappings of the pump. If long runs are encountered larger pipe must be used. Smaller pipe will reduce the capacity of the pump.
• All joints and connections should have pipe sealing compound (male threads only) applied and drawn up tightly.
• CAUTION: The entire system must be air and water tight for efficient operation.

Pump Installation

• If galvanized pipe is used, both the suction and discharge pipe should be supported ast a point near the pump to avoid strains being placed on the pump.
• The suction pipe should slope upward from the water source to the pump. Locate the pump as close to the water as possible keeping the suction pipe as short as conditions permit.
• A foot valve located in the water or a check valve located as close to the water as possible will reduce priming time of the pump and help maintain prime. A strainer must be used on the suction line to filter out dirt and debris.
• Install a gate valve or a full opening ball valve and a union in the discharge of line. Install a union in the suction line. For removal or the pump for service, close the valves and disconnect at the unions.
• CAUTION: Do not use globe valves or other restricting type of valve at the discharge. This will seriously restrict the capacity of the pump.

Wiring Connections

• Units are not waterproof and not intended to be used in showers, saunas, or other potentially wet locations. The motor is designed to be used in a clean dry location with access to an adequate supply of cooling air. Ambient temperature around the motor should not exceed 104 degrees Fahrenheit. For outdoor installations a cover that does not block airflow to and around the motor must protect motors. The units are not weatherproof nor is it able to be submerged in water, or any other liquid.
• Single-phase (3/4 - 2 HP) motors are dual voltage and can be connected for 115 volt or 230 volt service. The 3 HP single-phase motor is 230 volt only. Single-phase motors are usually factory connected for 230 volt at the motor.
• For proper electrical connections, refer to the connection diagram located on the nameplate of the motor. Make sure connections are correct for the voltage being supplied to the motor.
• CAUTION: To reduce the risk of electric shock, the motor must be securely and adequately grounded to a grounded metal raceway system, or by using a separate grounding wire connected to bare metal on the motor frame, or to the grounding screw located inside motor terminal box, or other suitable means. Refer to National Electrical Code (NECC), Article 250 (Grounding) for additional information.
• CAUTION: All wiring should be performed by a qualified electrician and in accordance with the National Electrical Code and local electric codes.
• WARNING: Always disconnect power source before performing any work on or near the motor or its power source, Failure to do so could result in personal injury or fatal electrical shock.
• WARNING: Failure to connect the motor frame to equipment grounding conductor by using green screw may result in serious electrical shock.

Motor Protection

• All single-phase motors have a built-in thermal protection for all voltages. The overload protects the motor against burnout from overload of low voltage, high voltage and other causes. The device is automatic and resets itself once the temperature has dropped to a safe point. Frequent tripping of the device indicates trouble in the motor or power lines and immediate attention is needed. The device should never be tampered with unless the trouble is located and corrected.
• WARNING: Never examine, make wiring changes or touch the motor before disconnecting the main electrical supply switch. The thermal device may have opened the electrical circuit.
• All motors should be equipped with a correctly fused disconnect switch to provide protection. Consult local and national electrical codes for proper fuse protection based on motor data chart.
• Undersized wiring can cause motor failure (low voltage), frequent cut-out of motor overload protector, television interference and even fire. Make certain the wiring is adequately connected to a separate circuit outside the house in case of fire.