how to: install a pump
In most situations, choosing a non-submersible over a submersible one is the best choice for several reasons. Power wise, non-submersibles consume less energy so running costs are lower. The motor also has a much longer life span so long term cost of ownership is lower. Non-submersible pumps do however cost more initially and require more effort to setup
pump installation Above or Below Pond Level ?
First you need to decide whether the pump will be installed above or below grade
. In the case of a non self priming pump, A pump that does not have the ability to pull water vertically up to it upon startup, the wet end needs to be full of water in order for it to pump
a wet install [below pond level] is usually desired. Unless your yard has a grade, this means the pump box is put in the ground. This removes any priming hassles and makes sure the pump always has a supply of water. However, the chance of the pump box flooding exists
but I have only seen this a handful of times
allow the installation to be above pond level coupled with easier priming. If you don't use a priming pot, you need a check valve and filling the line is more complicated this way. Priming pots also have a basket screen to catch debris that would otherwise enter the pump and clog it. It is much easier to clean out a pot rather than the pump
The ideal setup is a pump w/priming pot situated above grade but is still below pond level [wet installation]. Even self priming pumps can lose their prime, and if above grade, can burn out if the problem is not caught in time.
If you are not well experienced, dry fitting is highly recommended before you commit to gluing. Make sure you leave provision so that you can easily remove the pump at the later date for servicing and/or replacement. If you are below grade, this means incorporating gate/ball valves that are shut before the pump is removed. Flex hose and rubber couplers make this process simple - forget the anti-kink and poly fittings which are a nightmare to work with
I set up most pumps by gluing a small piece of pipe in each of the in and out pump fittings. Then, I use a rubber coupler and flex hose. Although more expensive than pipe, flex is a joy to work with. No elbows are required, it is flexible and easy to lay out and it can take freezing much better than rigid ABS or PVC - it is simply the superior choice. Make sure to purchase the rubber couplers that come with stainless steel clamps/bolts
There a few things to consider here. First, you never want to restrict the intake of a pump. If you require less flow, restrict the out put with a ball valve - this simply creates a greater head loss and subsequent reduction in flow
It's important to match the diameter of the pumps in and out with the same piping size. If the pump has intake and out put diameter's of 1.5 inches then use pipe of the same size. 1.5" is a typical bore for pumps up to 3,000 g.p.h. With longer runs, say 15-20 feet, friction charts should be checked and stepping up pipe bore to minimize head losses is advised
Debunking the 240V myth
Many people think that running their pump on 240 volts will cost less in hydro. Sure, it sounds correct, at double the voltage, the amperage is 50% so that's better right? I even repeated this as fact to people, having heard it so much myself.
After just completing an interesting Electrical Fundamentals course [winter 2004] I now know better
When you examine the power [watts] calculation, the amount of KWHr's [kilowatt hours] ends up being the same whether your pumped is connected to a 120 or 240 volt supply
P (power in watts) = I (Amperage in amps) x V (Voltage in volts)
So if you have a massive 9 amp pump on 120V you have P = 9A x 120V P = 1080 Watts
If you decide to get efficient and run this pump on 240V P = 4.5A x 240V P = 1080 Watts
So in the end, regardless of voltage, the pump ends up costing the same money to operate per kilowatt hour