Pedrollo Submersible Well Pump 7 GPM Series # 4SR7G

Questions & Answers

What basic questions must be answered before purchasing a submersible pump?

How much water will be required for daily use? And can the well produce enough water to meet daily requirements?

How do I determine how much water my well will produce in GPM (gallons per minute)?

You can refer to the driller's log or use of an older cleanout pump to determine flow rate.

How I Use of an older cleanout pump to determine the well flow rate?

Never use a new pump for this service. After cleanout pump operates for 30 minutes at free flow, fill a 5-gallon bucket and make a note of the time it takes to reach capacity. If at any time during the 30 minutes of free flow water fails to flow, pump should be turned off immediately. Wait 3 to 4 hours, lower pump deeper into well, and throttle (use a gate valve) pump back by closing valve 1/4 turn. This procedure should be repeated until water flows continuously for 30 minutes. Not doing so could result in dry running and destruction of the pump. The pump should never be closer than 10 feet to the bottom of the well.

What are the typical well pump sizes?

5 - 7 GPM Series: For low-capacity wells where a higher series would "over-pump" the well, causing pump failure; 10 - 13 GPM Series: For average-capacity wells. These are the most popular choices in farm and home applications; 20 to 27 GPM Series: For high-capacity wells where more than normal water supply is required: ranches, dairy farms, light irrigation, and light industrial water systems; 35 to 85 GPM Series: For very high capacity wells and/or very deep wells. For irrigation and industrial water systems where higher water volume is needed.

How do I determine depth of well?

Use the well driller's log or tie a heavy weight to a string, lower into well until it reaches bottom, and measure this distance.

What is the water pumping level?

The Water Pumping Level is defined as the standing water level in the well when the pump is operating, and the water being pumped out equals the water entering the well. This level is generally several feet lower than the water level in the well when pump is not operating. It should be understood that pump setting depth does not determine pump performance. The main criterion is the Water Pumping Level not the depth to water. The depth of the pump below this water level is of no significance in relation to gallons and pressure delivered by the pump.

Which is better, 2-wire or 3-wire?

A lot of this choice comes down to personal preference. The only difference between 2-wore and a 3-wire pump is where the motor starting components are located. In a 2-wire pump, all the motor starting components are located in the motor, down in the well. In a 3-wire pump, the motor's starting components are in a "control box" that is located above ground in your well house or basement. The one possible advantage of a 3-wire system is that if anything ever needs to be tested because of a problem, it is easier to test (and replace, if needed) the starting components that are above ground in the control box.

What are the typical submersible pump materials of construction?

Cast-iron basic construction represents good value and is useful in many applications; Thermoplastic construction provides excellent value and corrosion resistance; Stainless steel construction has superior corrosion resistance.

What is the pump capacity required?

Each outlet that may be left on for continuous use will require about 3 gallons per minute (GPM). A 1-bathroom house is usually sized for 2 continuous-use outlets, and a 2-bathroom house is usually sized for 3 continuous-use outlets. Livestock requirements are in addition to home requirements and, of course, must be added in order to determine the final volume requirement.

What is the pump pressure required?

Many homes use a 30 to 50 pressure (psi) setting. Higher cut-in and cut-out (40 to 60 psi) settings may be needed where automatic appliances require higher pressure for proper operation.

How do I know what horsepower pump to buy?

There are four things to consider in choosing the horsepower: 1) What is your depth-to-water? And 2) How much water do you need in your household? 3) How much pressure do you need? 4) What is the electrical requirement? Every pump is designed to work in a specific range of depth-to-water. You need to choose a pump that is designed to give you your required capacity in GPM at your particular depth-to-water and still have enough residual pressure to operate the system. .Remember - the more water your pump puts out, the bigger your pressure tank should be in order to prevent frequent cycling of the pump.

What is the actual diameter of a 4-inch well pump? Will it fit inside my 4" diameter well casing?

The 4" submersible well pumps have a diameter of about 3.875" (3- 7/8"). They really should NOT be put into a 4" diameter well casing. If the casing has any rust or bumps on the inside, or if it bends slightly, it would be possible for the pump to get stuck. Also, there might not be enough room around the pump for the water to flow properly into the intake of the pump. This can cause the pump to perform badly and for the motor to overheat.

What size well casing IS recommended for a 4" submersible?

For residential pumps, 4" submersibles work better in 5" or 6" well casings. If your well casing is larger in diameter than 6", then you should sleeve the pump so that it gets proper cooling.

I only have a 4" diameter well casing. Is there any option for a submersible well pump in this well?

You can install a 3" submersible well pump in a well with a 4" casing. Not to many companies sell 3" submersible pumps.

What does it mean to "sleeve" a submersible well pump?

To sleeve a pump, you put the pump into a piece of 6" diameter PVC pipe that is a little longer than the length of the pump. You put a 6" well seal on the top of the PVC pipe. In doing this, you are forcing the water to enter around the pump from the bottom. This forces the water to go up past the motor which cools the motor.

Can I put a 4" submersible into a cistern to pump water from it?

You can, but you must sleeve the pump

Can I put a 4" submersible into a lake to pump water out of it for my cabin or irrigation?

We suggest that a 4" submersible never be put into water where people or pets will swim. You are putting an electrical item into water. If a splice was to become exposed, or the electrical integrity of the motor were to fail, the water around the pump could be dangerously "charged" with electricity. It would be possible for someone to be injured or killed.

I’m putting in one of your 3-wire pumps to replace my old one. Do I have to use a new control box?

The control box is matched to a specific motor. In most cases, you will need to put in the new control box to match the new motor.

Do I need to put a check valve in the pipe down to my pump?

Most submersible pumps are equipped with a check valve in the discharge of the pump. It is not a bad idea to add an additional check valve for every 100' or so of drop pipe you use. This can help to break up the water column so that one check valve does not have to hold all the weight of the water.

I have a low-producing well. How do I make sure that the pump won't out-pump the well?

There are a couple different methods you can use to control the amount of water your pump will put out. If you know the rate at which water comes into your well (the recovery rate) then you can put a "dole valve" into the drop pipe. This will limit the amount of water that the pump is able to push out. Choose a dole valve that is the same as the recovery rate of the well and the water level in the well case won't drop. The other method is to put a "pump protector" on the pump. These are usually designed to work with 3-wire pumps. They go into the wiring and sense the power draw of the pump. If the power draw indicates that the pump is not moving water, it will shut off the power to the pump in order to protect it.

The pump I bought says it was in the "10 gallon-per-minute series" but it doesn't seem to be doing that amount. Why?

The pumps that are in the "10 gallon-per-minute series" are designed to flow about 10 GPM in the middle of their performance curve. It is close to the highest efficiency operating point for that pump. If the depth-to-water in your well is not quite as deep, the pump is going to flow more than 10 GPM. If the depth-to-water is a little deeper, then the pump is not going to put out quite as much. As long as the actual performance of your pump is within the rated range , the pump is OK to run in your setup.

I want to replace my pump myself. What kind of special tools are required?

We recommend that all pumps and pump repairs should be done by qualified and competent contractors. The toughest part of replacing a submersible well pump is the actual lifting of the pump and pipe out of, and then back into, the well. A 4" submersible well pump is going to weigh as much as 35 lbs or so. Add to that the weight of the pipe, wire, etc. and it could easily be more than a person can lift. It is recommended that you have some kind of lifting equipment if you want to try to do this yourself.

I'm putting in a new pump. Besides the pump, what other items do I need to have?

To work with the well itself (not the in-house items like tank, etc.) you will need the pipe and pipe fittings (enough to go down as far as you have figured out to be necessary), the wire (enough to go down to the pump and into the control box or pressure switch), some centering guides, a torque arrestor, and at least one check valve. If using PVC pipe you will need cleaner and glue for the connections. You may need to have. if the well driller did not install it for you, a pitless adapter to go into the well casing. Naturally, you will need an assortment of hand and power tools (hacksaw, pipe wrenches, electrical tools, etc.) You will also need lifting equipment to support the weight of the pump, pipe, etc. as you guide it into the well.

How far down do I put the pump in the well?

The pump needs to be set at a depth that is a minimum of 5' off the bottom of the well. If your well has a sandy bottom, in order to prevent the pump from picking up sand, it should be set more like 15' to 20' off the bottom.

What kind of pipe do I use for a drop pipe to support the pump?

You can use 100 psi-rated polyethylene plastic pipe (poly pipe) for setting depths down to 100'. Use 160 psi rated poly polyethylene plastic pipe ( poly pipe) for setting depths down to 220'. Use galvanized steel pipe for setting depths deeper than 220'. Schedule 80 PVC pipe can be used with threaded couplings at depths down to 500'. Use metal threaded couplings for setting depths below 300'. We recommend you never use regular Schedule 40 PVC

How important is it to use a safety rope or cable?

Using a safety rope or cable is very important. . If one of the fittings in the drop pipe fails, or even if an installer gets slippery fingers, the safety rope or cable will be the only way to retrieve the pump from the bottom of the well. We recommend a good stainless steel cable rather than rope. Rope (even nylon rope) can degrade over time in the damp environment of a well.

Ask a question about Pedrollo Submersible Well Pump 7 GPM Series # 4SR7G

Ask Question