Annual Water System Maintenance
We are often asked by our customers the question of what should be done for maintenance on a water system. Most water systems take very little maintenance but there are a couple of items that the home owners can do as an annual maintenance program.
Electrical Connections: Note: If you know nothing about electricity do not attempt this procedure and call a professional to provide this service.
In short: TURN OFF THE POWER TO THE EQUIPMENT and tighten all wire connections.
The heating and cooling of any metal component can at times loosen electrical wire connections. Often we get calls from our clients stating that there is a loud buzzing noise coming from the well pump control equipment. This load noise is most often caused by a loose terminal. A loose wire connection will actually cause a wire to heat up and if conditions are just right cause wires to burn in too. So before attempting to tighten any terminal(s) TURN OFF THE POWER TO THE EQUIPMENT. We strongly suggest using an electrical meter to confirm that the power is off in order to rule out the chance of getting an electrical shock. Most well equipment operations uses 230 volts, this means that each hot leg is carrying 115 volts of electricity. Well pump equipment must have a balance load or near balanced supply of power coming in. This is checked by measuring each leg of power to ground. The power coming in should not exceed or be less than 10% of 230 volts. This means the upper range should not exceed 253 volts on the high side and 207 volts on the low side. If these conditions occur, contact your electrical service provider and report your problem. Clean contactor and pressure switch contacts/points with a file to assure a good contact surface. One may use can air to clean dust and spider webs from switches. Never use WD-40 or similar sprays on contacts.
Note pertaining well pump control boxes mounted atop well head: It has been the practice of a few well pump installers in our local area to mount the control box atop the well head. In our opinion this is poor location for an electrical component, for the simple fact that the well breathes and produces moisture. We have seen multiple electrical problems occur from this moisture inside of the control box beyond the corrosion caused from the moisture. Most well caps have a fitting for a vent tube and a fitting for the submersible cable, with the control box atop the well head often the vent tube has been plugged off, or simply opened. The best scenario would be to remove the control box from the well head, but the easiest fix would be to take silicone caulking and filling the gap around submersible cable coming up through the well seal.
Captive air tank or standard tank (known to others as pressure tank) maintenance:
Note: The distribution pumps are designed to deliver a given volume of water at a given desired operating pressure. A properly sized and properly adjusted captive air tank in relation to the pressure switch is important to the operation and delivery of water. Proper adjustment of the captive air tank greatly contributes to the life of the distribution pump whether a submersible pump or a centrifugal/ booster pump.
Signs of captive air tank problems:
- There is a noticeable temporary drop in water pressure before the pressure comes back to full pressure. This problem is caused most likely by a low precharge air pressure condition in the captive air tank. Follow directions for checking precharge air pressure of captive air tank shown below.
- Distribution pump is short cycling or rapid cycling(starting and stopping in a very short duration of time). This problem is very hard on the distribution pump and if allowed to continue may cause severe damage to equipment. There are a couple of possibilities causing this problem, but the most common of these is a water logged tank. This means that the diaphragm or air bag has developed holes and the air cushion no longer exists. The easiest way to determine this is by depressing the air stem at the schrader valve atop the tank. Depress the air stem, under good working conditions only air will come out of the valve. If any water comes out of this valve, this would be an indication that there is a problem with the diaphragm/bladder/air bag. If one were to smell the air coming out of this valve on a tank in good condition the air should smell like rubber or the smell of an inner tube. If bad the air becomes sour in smell, this sour smell is real predominant with the summer time temperatures. This tank needs to be replaced.
If the pump is still short cycling and you’ve been able to determine that the tank is not water logged. The precharged air pressure has been confirmed to be in good adjustment
(see checking precharged air pressure) and it has been determined that there are no broken or open water lines, that which could be determined by shutting of the isolations valves after the captive air tank if not visibly noticeable. Another possibility of short cycling is caused by a pressure switch that has either gotten out of adjustment. This happens when the shut off pressure is less than the precharge pressure in the captive air tank. For this problem try adjusting the taller of the two adjustment nuts in the pressure switch by turning the adjustment nut clockwise until the desired shut off pressure is reached and the short cycling has stopped.
- Are there any visible water leaks around the captive tank or pressure tank? If you have a Spun fiberglass style of captive air tank often water is seen leaking out of the top of the tank. If water is visible there is a grater possibility that the tank needs to be replaced do to a bad diaphragm/bladder or air bag.
Checking precharge air pressure of captive air tank in short:
- Turn off power to the distribution pump once you have determined the operating pressure setting of the pressure switch. Example: does the pump come on at 40 psi and shuts off at 60 psi. Often the existing pressure gauge has sprung and does not so the correct pressure. What we suggest is to take tire gauge and check the pressure through the schrader valve atop the captive air tank. Start water running out of a garden hose or faucet, then note with your pressure gauge the pressure observed when the well pump comes on. Let the pressure build until the pump shuts off. There should be a twenty (20) pound differential between start up and shut down. If a increase in pressure is desired, only the taller of the two adjustment nuts should ever be adjusted. By turning this adjustment nut clockwise the pressure will increase keeping the twenty (20) pounds differential. The shorter adjustment nut, adjust only the upper end or shut off pressure and changes the differential setting. Note: Word of caution, there are limits to all centrifugal/ booster pumps shut off pressures. If pressure is increased beyond the pumps capability or shut off pressure, the pump will not shut off and damage to pump may occur if allowed to continuously run.
- To determine the precharge pressure, shut off the power to the distribution pump. Drain all water line pressure off, then with your tire gauge measure the pressure from the top of the tank as before. The air or precharge air pressure in the captive air tank needs to be within 2-4 psi less than the start up pressure. Add or decrease air pressure as needed.
Captive air tank general information:There are a couple of types of tanks that works with the pressure switch and pump used to distribute water, whether this is a submersible pump or a centrifugal/booster pump. The first tank we will make reference to is the most common style of tank used today and is known as a captive air tank or bladder tank. The captive air tank is a two compartment style tank where the water is in one compartment and pressurized air is in the other compartment, separated by a rubberized diaphragm or air bag (as in the spun fiberglass tanks), creating two chambers. When the precharge air in a captive air tank is properly adjusted and water lines are filled, water starts to fill the captive air tank compressing the diaphragm or air bag until the shutoff pressure is met. When a faucet(s) are opened the water in the captive air tank is pushed out by the compressed diaphragm/air bag until the small reservoir of water has been completely dispensed and the line pressure drops calling for more water. The air and water are separate of one another, unless there is a hole in the diaphragm or air bag. If a hole was to develop in the diaphragm or air bag, the captive air tank in time would become water logged.
The captive air tank has a couple of functions and the sizing of the captive air tank to the conventional operation (not a constant pressure system) of a distribution pump is very important. In essence the tank works much like the reservoir or tank on your bathroom toilet in that there is a volume of water that is available to use. The volume of water in the tank(s) determines the number of times the distribution pump cycles and the fewer times a pump cycles on and off the longer the pump motor will last. Tanks are most commonly sizes by the full volume of the tank. The most common size tanks are 81, 85-86 and 119 gallon tanks, which is a little miss leading for each of the fore mentioned tanks hold a much smaller volume of water or reservoir of water for uses. For example, a proper adjusted tank when working with a 40-60 pressure switch are as followed. An 81 gallon tank holds 21 gallon of water on reserve. A 85-86 gallon tank hold 23 gallons of water and a 119 gallon tank hold 32 gallons of water on reserve. Selecting the size of a captive air tank is determined by the gpm of the distribution pump and the desire to have the pump run a minimal of 1 minute between cycling. It is also important to keep in mind what the water use or demands are on a particular water system. A couple of small examples of water volumes used will be given in attempt to show how quick water is use from the reservoir of a captive air tank or tanks. People often have no idea of how much water they use, water from a 1/2 inch garden hose comes out at about 5 gallons a minute, the gpm increases as the hose diameter increases. Most shower heads in your home uses 5-7 gpm, so if there are multiple demands for water in the home at the same time, the amount of water on reserve plays a very important factor to what would be desired to have as a reservoir thus how many tanks are needed on a system to provide adequate run time for a given pump. Note: one can have large reservoirs but is the distribution pump for example only make 10 gpm, there is still only 10 gpm available. Thus a 10 gpm pump is best matched with a captive air tank of a minimum of 10 plus gallons on reserve. If a pump is capable of making 23-24 gpm it would be better to have a single tank with 32 gallon of water on reserve or two tanks with 23 gallons each on reserve.
Hydropneumatic or standard tanks: In short a tank without a bladder or diaphragm or air bag. This type of tank requires either that air is added to tank manually, air is added via a weep valve in the column pipe and a vacuum break valve or automatically by an air compressor to maintain air to water ratio. The hydropneumatic and standard tanks where devices used by many over the past years, mostly do to what was available at the time. If these tanks were not galvanized inside and out or epoxy coated, they have shown to have a very short life. It is Wickenburg Pump & Supply L.L.C. opinion that the cost for this style of tank out ways the benefit of the tank. Example: a 525 gallon standard tank adjusted properly and working with a 40-60 pressure switch, has 28.3 gallon of usable water available. Shown above a 119 gallon captive air tank, working with a 40-60 pressure switch has 32 gallons of usable water. There is no need to have a device to maintain the air to water ratio.
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