A deep well submersible pump is a multistage borehole pump built to push water up from a long way down, often 100 m or more. It gets that height by stacking many impellers, each adding head. Deep sets usually give modest flow at high head, run on three phase when they get large, hang on heavier pipe and cable, and often need a crane truck to install. This page explains what makes a deep set different, how to size it, and what a quote should list.
Many stages for high head
Each stage in a multistage pump adds a set amount of head at a given flow. A deep hole needs more stages, a longer pump and a stronger motor. The pump curve shows what flow you get at your total head; at very high head the flow falls away, so check the duty point carefully. In 4 inch sizes, deep sets suit houses and farms with low to moderate yield; 6 inch and larger pumps suit high yield holes on farms, mines and town supply. The basics are on borehole pumps.
Three phase, cable and voltage drop
Larger deep well motors usually run on three phase (400 V), which is common on farms and in industry. Some deep domestic pumps stay single phase. The longer the cable, the more voltage is lost before it reaches the motor, so deep sets need thicker drop cable; the installer works out the size from the motor current and the length. Undersized cable makes a motor run hot and fail early. On a large three phase set, a soft starter or variable speed drive also reduces the jolt on the pipe and the motor at each start. Protection matters more down deep: ask for phase failure, under and over voltage, dry run and surge protection in the control panel.
Pipe, rope and installation
A deep set is heavy. Many installers use HDPE poly pipe in a high pressure class for moderate depths, and steel column pipe for big or very deep sets. A stainless or nylon safety rope carries the weight if a joint fails. Lowering a long set by hand is risky, so a tripod with a winch or a crane truck is common. The cable is strapped to the pipe at regular gaps so it does not snag or chafe against the casing on the way down. Make sure the truck can reach the borehole on firm ground. See borehole pump installation and cable and pipe for the detail.
Old specs in feet and horsepower
You may have a spec sheet that says "250 ft" or "400 ft" and "5 hp". Convert before asking for quotes: 250 ft is about 76 m, 400 ft about 122 m, and 5 hp is about 3.7 kW. Give the supplier the depth to the pumping water level in metres, the flow you need and the power on site, and they can match a current pump rather than copying an old label.
What to put in your request
- Hole depth and pumping water level in metres
- Yield test result and flow wanted
- Single or three phase, and distance to the panel
- Old pump specs, even in feet or horsepower
- Access for a crane truck at the borehole
Deep Well Pumps for homes, farms and businesses
- Homeowners: a deep 4 inch set where the local water table is far down
- Smallholdings and plots: a deeper hole and multistage pump where shallow holes ran dry
- Farms: high head three phase sets for reservoirs, livestock and irrigation
- Complexes, estates and body corporates: a deep communal borehole feeding storage tanks for the complex
- Offices, shops, hotels and lodges: lodges, schools and hotels with deep backup boreholes
- Factories, plants and depots: process water from deep holes at factories and depots
- Mines and quarries: deep supply holes and shaft dewatering on three phase
- Municipalities, schools and clinics: town and village supply boreholes with large multistage pumps
- Contractors and drillers: installers with crane trucks setting and pulling heavy deep sets
Frequently asked questions
How deep can a submersible pump lift water?
Why does a deep pump need thicker cable?
Can a deep set be installed by hand?
Do you install deep well pumps?
Deep Well Pumps by province and city
- Johannesburg
- Pretoria
- Centurion
- Midrand
- Sandton
- Randburg
- Roodepoort
- Krugersdorp
- Randfontein
- Germiston
- Boksburg
- Benoni
- Kempton Park
- Alberton
- Vanderbijlpark
- Vereeniging
- Durban
- Pinetown
- Pietermaritzburg
- Richards Bay
- Newcastle
- Ladysmith
- Gqeberha (Port Elizabeth)
- East London
- Kariega (Uitenhage)
- Mthatha
- Cape Town
- Bellville
- Paarl
- Stellenbosch
- George
- Worcester
- eMalahleni (Witbank)
- Middelburg
- Secunda
- Mbombela (Nelspruit)
- Rustenburg
- Brits
- Klerksdorp
- Potchefstroom
- Mahikeng
- Polokwane
- Tzaneen
- Kimberley
- Upington
- Bloemfontein
- Welkom
- Sasolburg