Grundfos SQ and SQE are 3 in submersible well pumps built on a permanent-magnet motor with soft start and built-in dry-run, overload, over-temperature and voltage protection, so no control box or capacitor is needed. The range covers five nominal flow families of 5, 10, 15, 22 and 30 GPM in 34 hydraulic sizes from 40 to 450 ft nominal head, 1/2 through 1-1/2 HP, 115 V or 230 V single phase. SQ runs at fixed speed on a pressure switch and tank; SQE adds the Smart Motor and, paired with a CU 302 control unit, delivers variable speed and constant pressure over the existing power leads. All models fit a 3 in or larger well, set up to 500 ft below static level, for clear water to 86 F. We stock the U.S. 60 Hz pumps, both CU 302 builds, the PSI transducer, flow sleeve, cable kit and wrench in Houston. Send your pumping level, fixture count and target pressure for an engineering-led selection, or call 1-888.510.4036.
Five flow families, 34 hydraulic sizes, one motor platform: a permanent-magnet 3 in submersible with soft start and built-in dry-run, overload, over-temperature and voltage protection, no control box, no capacitor. SQ runs at fixed speed on a pressure switch. SQE adds a Smart Motor and, with a CU 302, variable speed and constant pressure. Engineering-led sizing from your pumping level and fixture count, and every part number in the range available to order.
5 to 30GPM families
34hydraulic sizes
40-450 ftnominal TDH
3 inminimum well
500 ftmax setting depth
Grundfos builds the SQ and SQE around a 3 in permanent-magnet submersible motor with an integrated micro-frequency converter, so the pump carries its own soft start and its own protection. A 2-wire single-phase design means the only thing between the breaker and the pump is a switch: no control box, no starter box, no capacitor. Floating polyamide impellers on tungsten carbide / ceramic bearings give the hydraulics a long life in sand, and the 304 stainless exterior fits any 3 in or larger well. SQ is the fixed-speed version for a conventional pressure switch and tank. SQE adds the Smart Motor, which talks to a CU 302 control unit over the existing power leads to hold constant pressure with a 2 gal diaphragm tank instead of a pressure tank.
We supply the U.S. 60 Hz range: five flow families of 5, 10, 15, 22 and 30 GPM nominal, 1/2 through 1-1/2 HP, 115 V or 230 V single phase, NPT discharge, along with the CU 302 controller, PSI transducer, flow sleeve, cable kit and wrench. Send us your depth to pumping water level, fixture count and target pressure and we will size it from the Grundfos curve. Compare the models below, or call 1-888.510.4036 and we will size it for you. Genuine Grundfos equipment, factory-new in original packaging — sold and supported by Watermain Supply, an independent industrial distributor.
The SQ / SQE Line
Same 34 hydraulics, two motors, one controller. Pick the flow family by GPM, the hydraulic by required head, and SQ or SQE by whether you want constant pressure.
SQ
Fixed speed, self-protecting
5-30 GPMnominal families
40-450 ftnominal TDH
1/2 to 1-1/2 HP115 V or 230 V 1Ph
MS 3permanent-magnet motor
The basic version of the range: a constant-speed pump that behaves like a conventional submersible on a pressure switch and pressure tank, but with an electronically controlled permanent-magnet motor that protects itself. Dry-run cut-out is factory set; the motor drops out below 150 V and above 315 V and restarts on its own when supply returns; a blocked rotor cuts power. The 1/2 HP sizes are built as separate 115 V and 230 V motors with their own part numbers; 3/4 HP and up are 230 V only.
Key specifications
5 SQ: 1 in NPT · 10 and 15 SQ: 1-1/4 in NPT · 22 and 30 SQ: 1-1/2 in NPT discharge
2.9 in over the cable guard, 3 in minimum well, 500 ft maximum setting below static level
Clear water to 86 °F, pH 5 to 9; 304 stainless sleeve, shaft and motor housing
Soft start, run-up under 3 seconds, no limit on starts per hour, power factor 1
Best forDomestic and seasonal-home wells, light commercial supply, irrigation and tank transfer where a pressure switch and tank are already in place or cost matters more than constant pressure.
The same hydraulics on the Grundfos Smart Motor. The motor communicates with a CU 302 control unit over the two power leads, so nothing extra is run down the well, and the controller varies speed between 3,000 and 10,700 rpm to hold a set pressure from a trickle to full flow. The duty point can be changed with the pump in the well. Without a CU 302 an SQE runs at maximum speed like an SQ; the constant-pressure and variable-speed functions need the controller.
Key specifications
Same 34 hydraulics, discharge sizes, voltages and protections as SQ
GENIbus to the CU 302 over the power cable; reset and soft stop via CU 302
Runs on a 2 gal diaphragm tank in constant-pressure service, not a conventional pressure tank
Grundfos HOME app monitoring and Grundfos GO commissioning through the CU 302 Bluetooth
Best forHomes and irrigation that want city-water pressure from a well, multi-fixture demand where a second tap should not drop the shower, and any installation where the setpoint may need to move later.
Control and communication unit for SQE pumps only. It reads a pressure transducer, starts the pump when flow is detected and adjusts speed to hold the setpoint. Two configurable I/O channels take analog sensors or digital switches, so the same box handles level control, pump-out and pump monitoring when the configuration is changed. Front-panel Grundfos Eye status, dry-run and service alarms, Bluetooth to the Grundfos GO and HOME apps. Two UL builds: with the PSI transducer, or without for installations that already have a sensor.
Key specifications
Power line communication: GENIbus over the pump power leads, nothing extra down the well
Analog in 0-10 V, 0-5 V, 0.5-3.5 V, 0-20 mA or 4-20 mA; sensor range 0-120 PSI
Operating -4 °F to +122 °F, 5-95 % RH; 9.1 x 6.3 x 3.8 in, 2.69 lb
Will not control an SQ or any pump outside the SQE range
Best forEvery SQE constant-pressure installation. Order with the PSI transducer unless the site already has a compatible sensor.
Dry run, no contact, overvoltage, overtemperature and overload reported on the CU 302 and in the apps
Reset after fault
Automatic on the pump
Automatic, or via CU 302
Hydraulic sizes
34, five flow families
Same 34
Voltage
1/2 HP: 115 V or 230 V 1Ph (separate part numbers); 3/4 HP and up: 230 V 1Ph
Same
Tank
Conventional pressure tank sized to the switch differential
2 gal (8 litre) diaphragm tank
Phone app
No
Grundfos HOME for the owner, Grundfos GO for the installer, via CU 302
Price position
Lower, and no controller to buy
Higher pump plus CU 302 and transducer
Quick rule. Choose SQ when the installation already has, or will have, a pressure switch and tank and the goal is a reliable self-protecting 3 in pump at the lowest system cost. Choose SQE plus CU 302 when the buyer is paying for constant pressure, wants to adjust the setpoint later, or needs fault reporting and app monitoring; an SQE without a CU 302 is an SQ at a higher price.
Rated Performance
Grundfos tabulates head at rated flow for every hydraulic in its system sizing matrix. The maximum-speed column is the working figure for both SQ (fixed at maximum speed) and SQE at full speed; the minimum-speed column is the floor an SQE can be turned down to with a CU 302.
Model (SQ / SQE)
Rated flow GPM
HP
Head at rated flow, max speed 10,700 rpm, ft TDH
Shut-off head at min speed 3,000 rpm, ft TDH (SQE only)
5 SQ05-90 / 5 SQE05-90
5
1/2
86
11
5 SQ05-140 / 5 SQE05-140
5
1/2
131
17
5 SQ05-180 / 5 SQE05-180
5
1/2
177
22
5 SQ07-230 / 5 SQE07-230
5
3/4
222
28
5 SQ07-270 / 5 SQE07-270
5
3/4
270
34
5 SQ07-320 / 5 SQE07-320
5
3/4
315
39
5 SQ10-360 / 5 SQE10-360
5
1
360
45
5 SQ10-410 / 5 SQE10-410
5
1
405
51
5 SQ15-450 / 5 SQE15-450
5
1-1/2
450
56
10 SQ05-110 / 10 SQE05-110
10
1/2
105
12
10 SQ05-160 / 10 SQE05-160
10
1/2
164
17
10 SQ07-200 / 10 SQE07-200
10
3/4
215
23
10 SQ07-240 / 10 SQE07-240
10
3/4
267
29
10 SQ10-290 / 10 SQE10-290
10
1
328
34
10 SQ15-330 / 10 SQE15-330
10
1-1/2
390
40
10 SQ15-370 / 10 SQE15-370
10
1-1/2
434
46
15 SQ05-70 / 15 SQE05-70
15
1/2
75
10
15 SQ05-110 / 15 SQE05-110
15
1/2
123
14
15 SQ07-150 / 15 SQE07-150
15
3/4
164
19
15 SQ07-180 / 15 SQE07-180
15
3/4
205
24
15 SQ10-220 / 15 SQE10-220
15
1
246
29
15 SQ10-250 / 15 SQE10-250
15
1
287
33
15 SQ15-290 / 15 SQE15-290
15
1-1/2
328
38
15 SQ15-330 / 15 SQE15-330
15
1-1/2
355
42
22 SQ05-40 / 22 SQE05-40
22
1/2
36
5
22 SQ05-80 / 22 SQE05-80
22
1/2
77
9
22 SQ07-120 / 22 SQE07-120
22
3/4
117
14
22 SQ10-160 / 22 SQE10-160
22
1
159
18
22 SQ10-190 / 22 SQE10-190
22
1
200
23
22 SQ15-220 / 22 SQE15-220
22
1-1/2
240
27
30 SQ05-40 / 30 SQE05-40
30
1/2
33
5
30 SQ07-90 / 30 SQE07-90
30
3/4
82
11
30 SQ10-130 / 30 SQE10-130
30
1
126
16
30 SQ15-170 / 30 SQE15-170
30
1-1/2
176
22
Flow ranges by family from the Grundfos sizing guide: 5 SQ 1.5-8 GPM, 10 SQ 3-15 GPM, 15 SQ 4-20 GPM, 22 SQ 7-33 GPM, 30 SQ 8-42 GPM. Horsepower is the Grundfos nameplate rating from the type key; generator sizing uses motor input power P1 plus 50 % per the instruction manual. Pressure in psi equals head in feet multiplied by 0.433. Each product page carries the depth-to-water by PSI table for its family; for a duty point outside that table, request the manufacturer curve. Confirm against the current Grundfos data booklet before specifying.
Sizing & Best Practices
How we size an SQ or SQE, following the Grundfos system sizing guide, and what to check before the pump goes in the well.
1. Calculate the required head, Hmax
Hmax = depth to pumping water level at maximum draw + elevation from grade to the tank or highest fixture + system pressure in feet (psi × 2.31) + friction loss in the drop pipe and discharge line. Use the pumping level, not the static level or the total well depth; drawdown at full flow is what the pump sees. Worked example: pumping level 120 ft, tank 10 ft above grade, 50 psi target (50 × 2.31 = 115.5 ft), friction in 1-1/4 in drop pipe and service line at 10 GPM roughly 12 ft. Hmax = 120 + 10 + 115.5 + 12 = 257.5 ft, call it 258 ft.
2. Estimate peak flow honestly
Residential: count water supply fixture units and read peak GPM from Hunter’s curve (IPC Table 604.3). A three-bath home lands around 10 to 15 GPM; irrigation zones add their own demand on top. Light commercial: use the IAPMO Water Demand Calculator. Pick the flow family whose rated flow sits at or just above the peak; the 10 GPM family covers most single-family wells, 15 and 22 GPM cover larger homes and irrigation, 30 GPM covers small waterworks and heavier irrigation. Cross-check a suspiciously low customer estimate against fixture count and the well’s tested yield before committing.
3. Select the hydraulic and check model limits
From the table above, take the first model in the chosen family whose head at rated flow exceeds Hmax. For the example, in the 10 GPM family the first figure above 258 ft is 267 ft, the 10 SQ07-240 or 10 SQE07-240. Then check the limits: a 3 in or larger well, the pump set at least 3 ft below maximum drawdown and never below the top of the screen, no more than 500 ft below static level, clear water no warmer than 86 °F at pH 5 to 9, and a flow sleeve for horizontal installation or where the motor may sit in sediment. For an SQE constant-pressure system, all calculated heads must also sit between the 3,000 rpm and 10,700 rpm curves.
Sizing rule of thumb. If the required head lands past 70 percent of a model’s maximum head at design flow, step up a model. In the example above 258 ft is 97 percent of the 240 hydraulic’s 267 ft rated head, so we would quote the 10 SQ10-290 (328 ft, 79 percent) and confirm on the Grundfos curve.
Which SQ or SQE Do You Need?
Selection by application; call with pumping level, fixture count and target pressure for an engineering-led pick and a factory-stamped submittal.
Application
Typical demand
Recommended
Notes
Cabin or one-bath seasonal home
5-8 GPM at 40-60 psi
5 SQ or 5 SQE family
1 in NPT discharge; 1/2 HP sizes available in 115 V where the service is limited
Two- to three-bath single-family home
8-15 GPM at 40-60 psi
10 SQ / 10 SQE or 15 SQ / 15 SQE
1-1/4 in NPT; the 10 family is the most common residential fit
Home with irrigation zones or a large family
15-25 GPM at 50-60 psi
15 SQE or 22 SQE with CU 302
Constant pressure keeps the house at setpoint while zones run
Light commercial, small waterworks, livestock
25-40 GPM
22 SQ or 30 SQ
1-1/2 in NPT; 30 SQ reaches 42 GPM; above that, step to a 4 in submersible
Tank filling, transfer, groundwater lowering
Any family by GPM
SQ, or SQE with CU 302 in level-control mode
CU 302 handles level filling and emptying on a digital or analog input
Replacing a conventional 3 in or 4 in pump in a tight or deep 3 in casing
Match existing
SQ family matched to the old pump’s GPM and head
Blow or bail the well clear of oil first if the old pump was oil-filled
Deep set, low-yield well
3-8 GPM
5 SQ10-410, 5 SQ15-450 or SQE equivalents
450 ft nominal head; dry-run protection covers a well that pumps down
What Makes SQ / SQE Different
The permanent-magnet motor and its electronics are the platform; everything below follows from it.
No control box, no capacitor
A 2-wire single-phase design driven by the motor’s own micro-frequency converter. The panel needs a breaker and a switch, and on SQE the CU 302. One less enclosure to buy, mount and troubleshoot.
Built-in dry-run protection
A factory-set cut-out pressure stops the pump when the well runs short, before the motor overheats. Low-yield wells and pumped-down irrigation cycles stop being a motor-killer.
Voltage and overload protection
The motor cuts out below 150 V and above 315 V and restarts when supply returns; under heavy load it drops to 3,000 rpm, then stops; a blocked rotor cuts power. No external relay or overload required.
Soft start, high starting torque
Run-up in under 3 seconds with no limit on starts per hour, so it tolerates a small tank and a short cycle. Starting reliability holds up at low supply voltage and on generators.
Floating impellers, sand tolerance
Glass-reinforced polyamide impellers ride on their own tungsten carbide / ceramic bearings rather than being fixed to the shaft, and a top bearing carries upthrust at start-up. Long life in sandy wells.
Any orientation
Built-in spring check valve and low weight allow vertical, horizontal or angled installation, so the pump fits cisterns and tanks as well as wells. A flow sleeve keeps motor cooling flow up when horizontal.
Power line communication (SQE)
The Smart Motor and CU 302 talk over the two power leads already in the well. Constant pressure, setpoint changes, fault reporting and app monitoring with no signal cable to splice or protect.
3 in stainless package
2.9 in over the cable guard, 304 stainless sleeve, shaft and motor housing, and discharge sized to the family. Fits 3 in casings that no 4 in submersible can enter, and still reaches 450 ft nominal head.
How SQ / SQE Compares to Conventional 4 in Submersibles
We sell 4 in induction-motor submersibles as well, so we can be straight about where each belongs. The comparison below is by architecture; model-level specs are on the individual product pages.
SQ / SQE vs 4 in 2-wire and 3-wire submersibles
Specification
Grundfos SQ / SQE
Conventional 4 in submersible
Minimum well casing
3 in
4 in
Motor
Permanent-magnet with integrated converter, single phase 2-wire
Induction motor; 2-wire with internal start components, or 3-wire with a control box
Control box and capacitor
None
Required on 3-wire; built into the motor on 2-wire
Dry-run, voltage and overload protection
Built into the motor
Added externally: pump-protection relay, overloads in the control box
Soft start
Standard, run-up under 3 seconds
Across-the-line start; soft start only with a separate drive
Constant pressure
SQE plus CU 302, over the power leads
Separate variable-frequency drive and sensor; 3-phase motor usually required
Horsepower and flow ceiling
1-1/2 HP, 42 GPM, 450 ft nominal
Ranges run to many horsepower and hundreds of GPM
Motor cooling and orientation
Any orientation; flow sleeve when horizontal
Typically vertical; flow inducer when set below the screen
Serviceability
Pump end and motor separate with the SQ wrench; motor liquid is SML-3
Industry-standard 4 in NEMA motor mount; motors interchangeable across brands
Honest verdict: a 4 in submersible wins on horsepower, flow and the flexibility of a standard NEMA motor mount, and the pump end plus motor can be cheaper at the same GPM and head. SQ / SQE wins in 3 in casings, in low-yield wells that need dry-run protection without add-on relays, on generator or marginal-voltage sites, and wherever the buyer wants constant pressure without a separate drive. Above about 40 GPM or 1-1/2 HP, step to a 4 in pump; see our Baker Water Systems 4 in submersible pumps.
SQ / SQE Accessories
Factory accessories that complete an installation, each ordered by its Grundfos product number.
CU 302 Control Unit
Constant-pressure controller for SQE; UL build with or without the PSI transducer.
Pressure Transducer
0-120 PSI, 1/2 in NPT analog sensor the CU 302 reads; required with the sensorless controller.
Flow Sleeve
304 stainless sleeve for horizontal installation or a motor set below the screen or in sediment.
Cable Kit
5 ft, 14 AWG NSF-listed motor lead for MS 3 and MSE 3 motors, model C; replaces a damaged factory pigtail.
SQ / SQE Wrench
Separates pump end from motor for motor-liquid service or a motor swap; not included with the pump.
Grundfos HOME and GO Apps
Free apps that pair to the CU 302 over Bluetooth: HOME for the owner, GO for commissioning.
Genuine Grundfos spare parts available by model and serial; contact us for the correct part. The controller and transducer are on the CU 302 page; cable kit, wrench and transducer are on the accessories page.
Why Source Grundfos SQ / SQE from Watermain Supply
Complete System, One Order
Pump, CU 302, pressure transducer, flow sleeve, cable kit and wrench on a single purchase order, so nothing is missing when the rig is on site. We confirm availability and lead time before you commit.
Engineering-Led Sizing
Send pumping level, fixture count, elevation and target pressure. We size from the Grundfos matrix and curve, check the limits, and can return a factory submittal before you commit.
Multi-Brand Perspective
If SQ / SQE is not the right fit, we will say so and quote the one that is. We sell 4 in submersibles and jet pumps too, so the recommendation is about the well, not the catalogue.
Every Part Number Listed
Both 115 V and 230 V part numbers on the 1/2 HP sizes, all 34 hydraulics, both CU 302 builds. What you order is what ships.
Account Terms Available
Net-30 for qualified contractor, well-driller, property-management and municipal accounts.
Parts & Aftermarket
Motor leads, wrenches, transducers, flow sleeves and CU 302 replacements for installed SQ / SQE systems, matched by model and serial.
Frequently Asked Questions
The questions we answer on the phone about SQ, SQE and CU 302.
What is the difference between Grundfos SQ and SQE?
Same 34 hydraulics and the same protections. SQ has a fixed-speed MS 3 permanent-magnet motor and runs on a pressure switch and tank. SQE has the MSE 3 Smart Motor, which communicates with a CU 302 control unit over the power leads to run at variable speed from 3,000 to 10,700 rpm and hold constant pressure.
Do I need a CU 302 with an SQE?
Only for constant pressure, variable speed, setpoint changes and fault reporting. Without a CU 302 an SQE runs at maximum speed like an SQ on a pressure switch. If you will never add the controller, buy the SQ.
Does an SQ need a control box?
No. SQ and SQE are 2-wire single-phase pumps with the converter and protection built into the motor. Do not connect either to a capacitor, to any control box other than a Grundfos CU unit, or to an external frequency converter.
Can I switch a 1/2 HP SQ from 230 V to 115 V?
No. The 1/2 HP sizes are built as separate 115 V and 230 V motors with different part numbers and are not field-convertible. The 3/4, 1 and 1-1/2 HP sizes are 230 V only.
What size well does an SQ fit?
Any 3 in or larger casing. The pump is 2.9 in over the cable guard. It can be set up to 500 ft below the static water level and must sit at least 3 ft below maximum drawdown and never below the top of the well screen.
How do I pick the model number?
Choose the flow family by peak GPM, then the first hydraulic whose head at rated flow exceeds your required head, which is pumping level plus elevation plus pressure in feet plus friction. Call with those numbers and we will size it and send a factory submittal.
What pressure tank does an SQE constant-pressure system use?
A 2 gal diaphragm tank. Because the pump follows demand instead of cycling between two switch settings, a conventional pressure tank is not needed. An SQ on a pressure switch uses a normal pressure tank sized to the switch differential.
Can the SQ run on a generator?
Yes. Grundfos recommends generator output equal to motor input power P1 plus 50 percent, and at least P1 plus 10 percent. The built-in under- and overvoltage protection cuts the pump out outside 150 to 315 V and restarts it when supply returns.
Can an SQ be installed horizontally?
Yes, vertically, horizontally or in between, as long as the pump does not fall below horizontal relative to the motor. Use a flow sleeve when horizontal so the motor keeps its cooling flow and is not buried in sand.
What does the CU 302 do besides constant pressure?
With its configuration changed it handles level control filling and emptying, pressure control on a digital or analog input, pump out and pump monitoring, using two configurable I/O channels. It also reports dry running, no contact, overvoltage, overtemperature and overload, and pairs by Bluetooth to the Grundfos HOME and GO apps.
Ready to Size Your Well Pump?
Send us your depth to pumping water level, fixture count, elevation to the tank and target pressure. We will respond with a sized SQ or SQE selection, the CU 302 and accessories, and lead time.
Technical data on this page is taken from Grundfos U.S. 60 Hz product literature and is subject to change by the manufacturer. Confirm against the current installation manual and pump curve before specifying.
Grundfos, SQ, SQE, CU 302, Grundfos GO, Grundfos HOME, GENIbus and Grundfos Eye are trademarks of Grundfos Holding A/S. Baker Water Systems is a trademark of its respective owner. All are used here for product identification only.
Watermain Supply is a DBA of E4 Industrial LLC, an independent industrial supplier based in Houston, Texas.
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