DOYIN 4SP8-21 4HP 3-Phase Stainless Steel Submersible Pump — 2" Outlet

The DOYIN 4SP8-21 is a robust 4HP three-phase AC submersible pump built with a stainless steel impeller for durability and corrosion resistance in demanding borehole conditions. With a 2-inch outlet and a maximum flow of 10.8m³/h (10,800 litres per hour), it's designed for high-volume water needs, delivering from a recommended depth of up to 110 metres (125M maximum head).

This pump suits mid-to-large agricultural irrigation, commercial water supply, and community boreholes requiring strong flow at a moderate lifting depth. The stainless steel impeller offers added protection against mineral content and mild salinity in borehole water, making it a solid option for coastal properties in Mombasa, Malindi, Diani, Kilifi, and Lamu, as well as inland agricultural operations with access to three-phase power.

As a three-phase AC pump, the 4SP8-21 requires a three-phase power supply and a matching three-phase AC controller sized to its 4HP rating for correct, protected operation. It is not solar-compatible in this configuration and is best suited to properties with stable grid or generator-backed three-phase electricity.

CoastalSolar Africa supplies, sizes, and installs the 4SP8-21 pump, including the correctly rated 3-phase controller, across the coastal region and for larger agricultural clients further inland.

Specifications:

• Model: 4SP8-21
• Power: 4HP, three-phase AC
• Impeller: Stainless steel
• Outlet size: 2 inches
• Max flow: 10.8m³/h (10,800L/h)
• Max head: 125M
• Recommended depth: 0–110M
• Power source: 3-phase AC (grid or generator)
• Required controller: Matching 3-phase AC controller, 4HP/3KW rating
• Application: Agricultural irrigation, commercial water supply, high-volume community boreholes

FAQs:

Does this pump run on solar power?
No — the 4SP8-21 is a three-phase AC pump requiring a stable 3-phase electricity supply. For solar-powered options, ask about DOYIN's DC or hybrid AD pump range.

What controller does this pump need?
It requires a matching 3-phase AC controller rated for 4HP/3KW — CoastalSolar Africa can supply and correctly match this.

Is the stainless steel impeller worth it for coastal boreholes?
Yes, it offers better resistance to mineral content and mild salinity often found in coastal borehole water compared to ordinary impeller pumps.

What's the maximum depth this pump can handle?
It's rated for a recommended depth of 0–110M, with a maximum head of 125M.

How does this compare to the 4SP8-16 (3.0HP)?
Both share the same 10,800L/h max flow and 2" outlet, but the 4SP8-21 delivers greater lifting capacity (125M max head vs 96M) at a higher 4HP rating.

Do you install 3-phase pumps in Kilifi and Malindi?
Yes, CoastalSolar Africa supplies and installs 3-phase submersible pumps like the 4SP8-21 across Mombasa, Malindi, Diani, Kilifi, Lamu, and inland agricultural areas with 3-phase power access.