Grundfos · 4 in Constant Pressure Well Pump Package
35S30-11 CUE 100
Constant-pressure well water package under one Grundfos order number: a 35S30-11 stainless steel SP pump end, a 3 HP 4 in three-phase motor and a CUE 100 30 drive with its pressure transducer. Runs from 208-230 V single-phase service.
35 GPM Rated Flow
232-237 ft at 35 GPM
3 HP
208-230V 1Ph In · 3Ph Motor
Constant Pressure · Transducer Included
4 in Min. Well
1-1/2 in NPT Discharge
NEMA 4X Outdoor Drive
93 lb Ship Weight (Package)
Overview
This package brings together the three Grundfos components of a constant-pressure well system: the 35S30-11 pump end, a 3 HP 4 in three-phase submersible motor and the CUE 100 variable-frequency drive. The drive reads the included pressure transducer and changes pump speed to hold the pressure you set as taps open and close, so the house sees steady pressure instead of a pressure switch's swing.
The CUE 100 takes 208-230 V single-phase power and makes three-phase power for the motor, so you get a three-phase pump's smooth, soft-started running on ordinary single-phase service. The drive is NEMA 4X / IP66 for outdoor mounting and is set up at its keypad or over Bluetooth with the free UnyConnect app.
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Steady pressure. The drive holds the setpoint from one tap to full flow and slows the pump when demand drops.
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Stainless steel SP hydraulics. AISI 304 impellers, chambers and outer parts, a built-in check valve and a sand-handling bearing design.
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Diagnostics at the wellhead. Time- and date-stamped alarms and warnings at the drive and in the app; Modbus, BACnet and Bluetooth connectivity.
What Ships and What It Needs to Run
Included, under order number 93336418: the 35S30-11 SP pump end (98924023), a 3 HP 4 in three-phase MS4000 motor (92959950) and the CUE 100 30 drive (92939800) with its pressure transducer. Grundfos lists them as three components of one package.
Required, ordered separately: a diaphragm pressure tank sized to the CUE 100 instructions, drop pipe, submersible drop cable and splice kit for your setting depth, and a 208-230 V single-phase supply and breaker for the drive.
Never connect the motor straight to the supply. It is a three-phase motor and runs only from the CUE 100.
Replacement parts: the drive alone is on our Grundfos CUE 100 Constant Pressure Drive listing, the motor on our Grundfos MS 4 in motor listing and the pump end on our Grundfos 35S SP pump end listing.
Genuine Grundfos equipment, factory-new in original packaging — sold and supported by Watermain Supply, an independent industrial supplier.
Warranty
24 months from date of installation, but not more than 30 months from date of manufacture. In Grundfos's words, products are “warranted to the original user only to be free of defects in material and workmanship”; the full terms are in the installation and operating instructions on the Data Sheet tab.
Specifications
| Specification |
Value |
| Package order number |
93336418 |
| Pump end |
35S30-11, 35 GPM rated, AISI 304 stainless steel (98924023) |
| Motor |
3 HP, 4 in, three-phase MS4000 (92959950) |
| Drive |
CUE 100 30, 12.5 A max motor service-factor current, NEMA 4X / IP66 outdoor (92939800) |
| Drive supply |
208-230 V, single phase in; three phase out to the motor |
| Pressure transducer |
Included with the drive |
| Discharge |
1-1/2 in NPT |
| Minimum well |
4 in |
| Shipping weight |
93 lb, complete package |
Source: Grundfos US groundwater price list, January 2026 (4 in CUE 100 packages and CUE 100 drives).
Models & Performance — Will It Do What You Need?
The first table reads like the curve: the head the pump adds from shut-off to the end of its curve. The second shows what it delivers while the drive holds 40, 50 or 60 PSI at your pumping water level.
| Model |
HP |
0 GPM (Shut-off) |
9.1 GPM |
22.6 GPM |
35 GPM (Rated) |
45.3 GPM (Max) |
| 35S30-11 |
3 |
320 |
312 |
291 |
232-237 |
173 |
Total head in feet. The shut-off and flow columns are read from the Grundfos 60 Hz curve for the 35S30-11, digitized from the published vector curve in the Grundfos SP 35S data sheet (60 Hz), at the nearest published point and rounded down. The (Rated) column is the nominal head Grundfos prints for the 35S30-11 at 35 GPM, verbatim. 1 ft of head = 0.433 PSI. Full curves are in the product images and on the Data Sheet tab.
What It Delivers at Your Set Pressure (GPM by depth to water)
| Set pressure |
40 ft |
80 ft |
100 ft |
120 ft |
160 ft |
200 ft |
220 ft |
| 40 PSI |
— |
— |
43 |
40 |
33.5 |
22.5 |
9 |
| 50 PSI |
— |
42.5 |
39.5 |
36.5 |
28 |
5.5 |
— |
| 60 PSI |
44.5 |
39 |
36 |
32 |
20 |
— |
— |
Calculated, not printed: Grundfos prints no easy selection chart for the 35S. Each cell is the flow where the published Grundfos SP 60 Hz curve for the 35S30-11 meets the depth to water plus the set pressure (2.31 ft per PSI), interpolated between published points and rounded down to 0.5 GPM, at full speed. Riser and pipe friction are not included. A dash on the shallow side means the flow runs past the end of the published curve; on the deep side, the pump cannot hold that pressure.
Before You Buy — The Limits That Decide the Fit
| Check |
What to confirm |
| Well size |
4 in or larger casing |
| Power |
208-230 V single-phase supply to the drive; the motor runs only from the drive |
| Water |
Up to 104°F with at least 0.25 ft/s flowing past the 4 in motor; drinking water up to 86°F |
| Pressure tank |
A diaphragm tank sized to the CUE 100 instructions, between the well and the first tap |
| Drive location |
Wall-mounted, indoors or outdoors (NEMA 4X); keep within the drop-cable length the CUE 100 instructions allow |
Materials of Construction
| Part |
Material |
| Impellers, chambers, strainer, cable guard |
AISI 304 stainless steel |
| Pump shaft |
Stainless steel, EN 1.4057 |
| Bearings |
NBR elastomer |
| Motor |
Water-filled Grundfos MS submersible motor, stainless steel |
Source: Grundfos SP data booklet, standard S construction.
