JS GS Grinder Sewage Submersible Pumps

Where to Use JS GS Grinder Pumps

A grinder pump earns its place when the discharge route is the problem. Typical jobs include a basement toilet or shower room below the level of the main sewer, an annexe, garden office or holiday let a long way from the nearest drain, and a site welfare unit that has to pump up to a manhole on the road. Because the waste is shredded first, you can run 32 mm or similar small-bore pipe instead of trenching in a large-bore rising main, which saves a great deal of digging on a long run. JS Pumps also lists package sewage stations, portable sewage pumping and farm or process waste water with organic solids among the uses for this design.

Size the pump on the total head it must work against, not just the height difference. Every metre of vertical lift counts, and so does friction in the pipe, which adds up quickly on long runs of small-bore pipe. Our guides to pump head and flow rate and how a sewage grinder pump works explain both. If your discharge point is close by and only a few metres up, a grinder may be more than you need: a vortex pump such as the JS SV sewage range passes solids whole rather than cutting them and has no cutter to wear.

Frequently Asked Questions

Should I choose a grinder pump or a vortex sewage pump?

Choose a grinder when you need height, distance or small-bore pipe. A vortex pump uses a recessed impeller that lets solids pass through without cutting them, so it needs larger-bore discharge pipe and generally works at lower heads. For a short, low lift into a nearby drain, the vortex pump is usually the simpler option.

What is the difference between the GS-1200 and the GS-1500?

Motor size and head. The GS-1200 has a 1.2 kW motor and lifts to 19 metres; the GS-1500 has a 1.5 kW motor and lifts to 22 metres. Both share the 1¼-inch outlet and the same 190 l/min maximum flow, but the GS-1500 holds more of its flow as the head increases, so it is the one to choose for longer or higher discharge runs.

Can I run the 110v GS-1200 from a site transformer?

Yes, that is what the 110v version is for, but check the supply first. It draws 20 A, which is more than a standard 16 A 110v outlet can provide, so you need a transformer and socket rated for the load. There is no 110v GS-1500.

Do I need a float switch or control panel?

The automatic models carry a MAC 3 float switch and will run unattended. Manual models need separate level control, such as a float switch or control panel, in a permanent installation; our float switch guide covers the options. For a fixed sewage sump, a high-level alarm is a sensible addition whichever version you choose.

What should not go into a grinder pump?

The cutter is designed for soft solids in sewage. Sand, gravel, stones and other hard debris wear or jam it, so keep site run-off and builders’ waste out of the sump. These pumps are also not for oils, solvents, chemicals or flammable liquids.

Can the pump be installed on a guide rail?

Yes. The side vertical outlet is removable so the pump can sit on a coupling foot, letting you lift it out of a chamber for servicing without disconnecting the pipework.

If you would like help sizing a GS pump for a particular head, pipe run or site supply, call the AES Rewinds team on 01252 515169 or email sales@aesrewinds.com. You can also browse all sewage pumps or the full JS Pumps range.