JS Heavy Duty Contractor Pumps

Where to Use JS Heavy Duty Contractor Pumps

These are the pumps you find on most UK construction sites and in most hire depots. They dewater foundations, trenches, lift pits and basement excavations, empty flooded cellars, plant rooms and car park sumps, and keep water features and temporary works drained. The cast iron construction takes knocks that would crack a plastic-bodied pump, which is why plant hire companies stock them in numbers.

Match the size to the job rather than buying the biggest pump. A JS-400 on a 2-inch hose clears most trenches and sumps; step up to the JS-750 or JS-1500 when the inflow is high or the water has a long way to go. Lift height and hose length both cut flow, so if the discharge point is well above the pump, compare the curves or choose the high-head JS-1500H. Our guide to pump head and flow rate explains how to read them, and our guide to discharge pipe sizing shows why a 3-inch hose helps on long runs.

Know where the range stops. These are drainage pumps for clean and dirty water with small solids; they are not built for raw sewage or rag. For that, look at the JS SV sewage vortex pumps. For three-phase sites, the JST and JST-H range is the 400v equivalent; for corrosive water there is the JS 316 stainless steel range; and where the pump must keep running in shallow water, the RS top outlet range is designed for continuous duty.

Frequently Asked Questions

What does the number in JS-250, JS-400 and JS-750 mean?

It is the motor size in watts: 250 W, 400 W, 750 W and 1,500 W. A bigger motor gives more flow and more head. The JS-1500H uses the same 1.5 kW motor as the JS-1500 but with a high-head pump end, so it lifts water higher at a lower flow.

Should I choose the 2-inch or 3-inch JS-750?

Both deliver the same flow and head, so the choice is about hose. Pick the 2-inch version if your site already runs 2-inch layflat and couplings, and the 3-inch version for long runs, where the larger hose loses less to friction and you get more of the pump’s flow at the discharge end.

Is there a 110v JS-1500?

No. The JS-1500 and JS-1500H are 230v only, because a 1.5 kW single-phase motor would draw too much current for a typical 110v site transformer. On a 110v site, the JS-750 is the largest model in this range, or use a three-phase JST pump where 400v is available. Note that the 230v JS-1500 draws 12 A, so it needs a supply that can carry that comfortably.

How does the automatic version work?

Automatic models are fitted with a MAC3 tethered float switch. The float rises with the water and starts the pump, then drops and stops it as the level falls, so the pump can be left unattended. Leave about 300 mm of free space around the pump so the float is not trapped against the side of a sump. Manual pumps can be automated later with a separate float switch; our float switch guide covers the options.

What can these pumps handle?

Clean and dirty water containing small solids such as silt, sand and grit, which is typical of site dewatering and flood clearance. They are not designed for sewage, sludge, rag or fibrous material, or for water containing oil or chemicals.

Can they pump a floor dry?

No. Like any standard submersible, they stop drawing once the water falls below the intake. To clear the last few millimetres from a floor or slab, follow on with a residue pump such as the JS RSD 150 Puddle Buddy.

If you would like help choosing a JS pump for a particular site, sump or hire fleet, call the AES Rewinds team on 01252 515169 or email sales@aesrewinds.com. You can also browse the full JS Pumps range or all drainage pumps.