Grundfos controls, variable-frequency drives, motor protection and service parts for SP, SQ and SQE submersible well pumps. SA-SPM6 control boxes start 3-wire single-phase motors; the MP 204 protects and monitors any motor; CUE and CUE 100 drives hold constant pressure; sine-wave filters, enclosure kits, motor leads and attachment kits complete the installation. Genuine Grundfos equipment in U.S. 60 Hz configuration. Tell us the pump model, motor nameplate and supply voltage and we will match the part. Call 1-888.510.4036.
Grundfos Submersible Controls, Drives & Motor Accessories
The controls, variable-frequency drives, motor protection and service parts that complete a Grundfos SP, SQ or SQE well pump installation. Control boxes, MP 204 protection, CUE and CUE 100 drives, sine-wave filters, motor leads and attachment kits. Call 1-888.510.4036 and we will match the accessory to your pump.
11Accessory groups
1/2–300 HPMotor coverage
115–500VVoltage range
SP / SQ / SQEPump families served
GenuineGrundfos parts
Grundfos builds a full range of controls and service parts around its SP, SQ and SQE submersible pumps: the SA-SPM6 control box that starts a 3-wire single-phase motor, the MP 204 electronic motor protector, the CUE and CUE 100 variable-frequency drives for constant-pressure operation, the enclosure kits and sine-wave filters those drives need, and the motor leads and attachment kits a service tech reaches for.
We supply these accessories in their U.S. 60 Hz configuration and will match each one to the pump, motor and supply on your job. Tell us the pump model, the motor nameplate and the supply voltage and we return the right part number. Call 1-888.510.4036 or email sales@watermainsupply.com. Genuine Grundfos equipment, factory-new in original packaging — sold and supported by Watermain Supply, an independent industrial supplier.
The Accessory Groups
Seven groups cover the controls, drives and service parts around a Grundfos submersible pump. Find the one that matches your pump and motor, then select the exact part on the product page.
SA-SPM6 Control Box
Starting control, 3-wire motors
1/2–15 HPMotor range
115 / 230V1-phase
IP42 / NEMA 3REnclosure
Std / DeluxeBuild
The starting unit a 3-wire single-phase submersible motor needs. Standard boxes carry the potential relay, capacitors and a motor protective circuit breaker; Deluxe boxes add a motor contactor. Matched to the motor by HP and voltage.
Best forAny SP well pump built with a 3-wire single-phase motor.
Electronic protection and monitoring for single- and three-phase motors: overload, underload and dry-run, voltage and phase faults, temperature, insulation resistance and full fault history. Reads out on its display and trips a relay.
Best forAny installation that needs motor protection and operating data beyond a basic starter.
The wall-mounted CUE drive brings constant pressure, dry-run protection and soft start to an SP or SPE pump. Selected by supply, output current and enclosure; the enclosure kit, sine-wave filter and pressure transducer are matched to it.
Best forLarger SP and SPE systems needing constant pressure or single-to-three-phase conversion.
The compact CUE 100 runs a three-phase SP motor from a 200-240V single-phase supply and holds constant pressure, transducer included. The same drive supplied in the CUE 100 well pump packages.
Best forResidential and light-commercial constant-pressure wells on single-phase service.
Everything that completes a CUE drive: the IP21 enclosure kit that brings an IP20 drive to NEMA 1, the matched sine-wave output filters, the MCB 114 sensor and MCO 101 multipump modules, local control panel, mounting and connection kits.
Best forCompleting or servicing a CUE drive installation to spec.
The service parts a submersible motor needs: replacement motor leads for MS402, MS4000 and MS6000C motors, and the nut and bolt kits that couple an SP pump end to its motor, from 4 in through 10 in, including the PT100 sensor bolt kit.
Best forServicing or assembling an SP pump-and-motor combination.
Start from the pump and motor you have, then pick the accessory. Call with the pump model and motor nameplate and we will confirm the part.
Accessory
Pump / motor it serves
What it does
Notes
SA-SPM6 Control Box
SP with 3-wire single-phase motor
Starts the motor; matched by HP and voltage
Required for a 3-wire single-phase motor to run
MP 204 Protector
Any SP, SQ or SQE with a standard starter
Protects and monitors the motor
Optional but recommended on higher-value installations
CUE Drive
SP / SPE, three-phase, larger HP
Constant pressure, soft start, dry-run protection
Add IP21 kit, sine-wave filter and transducer
CUE IP66 Drive
SP / SPE mounted outdoors or washdown
Same control in a sealed enclosure
Transducer separate; no factory filter pairing published
CUE 100 Drive
SP, three-phase motor on 1-phase supply
Constant pressure, transducer included
Select by motor service-factor amps
IP21 Enclosure Kit
IP20 CUE drive, frames A3–C4
Brings the drive to NEMA 1
One kit per drive, matched to the frame
Sine-Wave Filter
CUE drive on a long motor cable
Smooths the drive output to the motor
Matched to the drive part number
Motor Leads
MS402, MS4000, MS6000C motors
Replaces the motor lead assembly
Match motor family and wiring
Nut / Bolt Kits
SP pump end to MS / MMS motor
Couples pump end to motor
Match the exact motor family
Rule of thumb. A 2-wire single-phase motor needs no control box. A 3-wire single-phase motor needs the SA-SPM6. A three-phase motor needs a starter or a CUE drive. Constant pressure across changing demand means a CUE or CUE 100.
Selecting a CUE Drive
The CUE is selected by the motor, not by horsepower alone. Work through supply, current and enclosure in order.
1. Match the supply
Confirm the available service: 200-240V single-phase (small drives only), 200-240V three-phase, or 380-500V three-phase. The CUE 100 is the single-phase-in, three-phase-out option for smaller SP motors; the CUE covers the rest.
2. Select by service-factor amps
Pick a drive whose rated output current clears the motor's maximum service-factor current, with margin for cable length and duty. Grundfos publishes an SP-motor-HP figure against each drive current in the Groundwater Guide; that mapping is on the product page.
3. Choose the enclosure
IP20 drives need the IP21 enclosure kit to meet NEMA 1. NEMA 12 drives include a backplate and disconnect. The IP66 CUE is for outdoor or washdown mounting.
4. Add the filter and transducer
Long submersible cable runs call for a sine-wave output filter, matched to the drive part number. The pressure transducer (0-120 PSI, 1/2 in NPT) is ordered separately; the CUE 100 includes its transducer.
Note. Five of the higher-current sine-wave filters are IP23 and not UL Listed. Where a project specification requires a UL Listed filter, confirm before ordering.
How These Accessories Work
What each technology does on a submersible installation.
3-Wire Starting
The SA-SPM6 potential relay disconnects the start winding once the motor is up to speed, so a 3-wire motor starts hard and runs on its main winding.
Full Motor Protection
The MP 204 watches overload, underload and dry running, voltage and phase, temperature and insulation resistance, with a time-stamped fault log.
Constant Pressure
A CUE or CUE 100 varies motor speed on pressure feedback, holding a steady pressure across changing demand instead of cycling the pump.
Single-to-Three-Phase
The CUE 100 and single-phase-input CUE drives run a three-phase motor from single-phase service — three-phase efficiency on a residential supply.
Sine-Wave Filtering
On long submersible cable runs a sine-wave filter smooths the drive output, protecting the motor windings and cable insulation.
Grundfos GO
The MP 204 and CUE drives connect to Grundfos GO over the MI 301 interface for setup, status and fault reading from a phone.
Matched Service Parts
Motor leads and attachment kits are cut to the exact motor family — MS402, MS4000, MS6000C, MMS — so a service part fits the first time.
One Source
Pump, motor, control and drive all come from one order, matched at selection, rather than sourced piecemeal from mismatched vendors.
Why Source Grundfos Accessories from Watermain Supply
Engineering-Led Sizing
Send the pump model, motor nameplate and supply voltage and we return the exact accessory part number, sized against the Grundfos data.
Matched To Your Pump
We match the control, drive or service part to the SP, SQ or SQE it serves — no guessing at HP, voltage or motor family.
Multi-Brand Perspective
If a Grundfos accessory is not the right answer for your installation, we will say so and point to the one that is.
Correct US Build
U.S. 60 Hz configuration and NPT where it applies — the build that drops into a North American installation.
Account Terms Available
Net-30 for qualified contractor, property-management and municipal accounts.
Houston, Gulf Coast Service
Based in Houston and serving the Gulf Coast, with parts and aftermarket support for the Grundfos submersible range.
Frequently Asked Questions
The questions we hear most on Grundfos submersible accessories.
Do I need a control box?
Only for a 3-wire single-phase motor, which uses the SA-SPM6 to house its start capacitor and relay. A 2-wire single-phase motor has its starting components built in and needs none; a three-phase motor uses a starter or a CUE drive instead.
What is the difference between the CUE and the CUE 100?
The CUE 100 is a compact constant-pressure drive that runs a three-phase SP motor from a single-phase supply, with the pressure transducer included. The CUE is the full drive range — larger currents, more supply options, more enclosures and modules — with the transducer ordered separately. They are separate families and their accessories are not interchangeable.
How do I size a CUE drive?
Match the available supply first, then choose a drive whose rated output current clears the motor's maximum service-factor current with margin for cable length and duty. The product page lists the Grundfos SP-motor-HP figure against each drive current.
When do I need a sine-wave filter?
On long submersible cable runs, where the drive's switching output can stress the motor windings and cable. The filter is matched to the drive part number; the pairing table is on the filter product page.
What is the MP 204 for?
It is electronic motor protection: overload, underload and dry-run, voltage and phase faults, temperature, insulation resistance and a fault log, reading out on its display and tripping a relay. It protects motors up through 75 HP directly, more with external current transformers.
Which motor lead do I need?
Match the motor family and wiring configuration from the nameplate — MS402, MS4000 or MS6000C, and 2-wire or 3-wire. Lead length alone does not determine the part.
Do these work with SQ and SQE pumps?
SQ and SQE pumps use their own CU 301 and CU 302 controllers rather than a control box, and the MP 204 protects any standard-starter installation. The CUE drives are for SP and SPE pumps. Tell us the pump and we will confirm what fits.
Are these genuine Grundfos parts?
Yes — factory-new Grundfos equipment in original packaging. The TCI sine-wave filters are manufactured by TCI and supplied under Grundfos part numbers.
Need The Right Accessory?
Send us your pump model, motor nameplate and supply voltage. We will confirm the control, drive or service part you need, with the matched kit and filter, 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 before specifying.
Grundfos, CUE, SP, SQ and SQE are trademarks of Grundfos Holding A/S; TCI is a trademark of TCI, LLC — 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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