Grundfos CRNE 3 Variable-Speed Pump, 1 1/4 in ANSI, 4000 rpm

CRNE 3 is the Grundfos CRN pump with the drive built into the motor. The Grundfos MLE motor carries its own variable frequency drive and PI controller, so the pump sets its own speed to hold a setpoint as demand changes. There is no separate drive to buy, mount, wire or commission, and no motor-protective circuit breaker to add: the drive protects the motor and electronics against overload, and the supply needs only normal short-circuit protection for the cable.

Every part in contact with the liquid is AISI 316 stainless steel. Grundfos builds the CRNE for industrial liquids and for systems where all wetted parts must be high-grade stainless: reverse osmosis, ultra-filtration, demineralising and distillation, acids and alkalis, glycols, oils and process water. For clean cold or hot water, the cast-iron and 304 stainless Grundfos CRE 3 is the matching pump.

This listing is the 4000 rpm build with 1 1/4 in ANSI flange, 300 lb class connections. Grundfos publishes the 4000 rpm and 3600 rpm builds as separate part numbers, so they are listed separately rather than mixed. It covers 12 models from CRNE 3-2 to CRNE 3-21, 1/2 to 5 HP, on 200-240V 1Ph; 200-240V 3Ph; 440-480V 3Ph supplies, each with or without a factory pressure sensor.

Suction and discharge sit on the same level, so the pump drops into a straight pipe run. It is set up at the factory: connect power, set the pressure you want, and it runs.

24 months from the date of installation, but not more than 30 months from the date of manufacture. Grundfos warrants its products to the original user to be free of defects in material and workmanship for that period, and repairs or replaces at its option.

In Grundfos’s words: “Grundfos will not be liable for any costs of removal, installation, transportation, or any other charges that may arise in connection with a warranty claim.” Keep the proof of purchase and the installation date; both are needed for a claim.

The CRNE runs as a complete single pump. For duty/standby or staged multi-pump boosting, Grundfos builds these pumps into Hydro MPC and Hydro Multi-E systems, specified as a set with the control. Ask us if that is what the job needs.

For a building management system, a Grundfos CIM communication module connects the pump so setpoint, control mode and status can be read and changed remotely.

With sensor. The pump ships with a factory pressure sensor fitted to the outlet and set to constant pressure. Set the pressure you want and the pump varies its speed to hold it, whatever the flow. It can also be switched to constant-curve operation. This is the version to order unless you already know otherwise.

Without sensor. The same pump, drive and panel, with no sensor supplied. It leaves the factory in open-loop constant-curve operation, ready for an external speed or setpoint signal from a controller or building management system. Fit a sensor later and it can hold pressure, differential pressure, temperature, differential temperature, flow or tank level.

• Variable frequency drive built into the motor — continuous speed control to hold a setpoint, with built-in motor protection.
• Totally enclosed, fan-cooled Grundfos MLE motor, Ultra Premium Efficiency class, insulation class F.
• HMI 300 operating panel as standard, for setpoint and operating mode at the pump.
• Grundfos GO app — the smaller MLE motors talk to it by radio or infrared through the MI 301 module; the larger three-phase motors have built-in Bluetooth.
• In-line ports — suction and discharge on the same level.
• Cartridge shaft seal with silicon-carbide seal faces.
• 1 1/4 in ANSI flange, 300 lb class connections.

The duty point of each model. Every part number above has its own curve. Send us the flow and pressure you need and we will read the exact model off the Grundfos curve and send it back before you order.

Drawing from a tank, cistern or well. Nothing arrives with pressure, so what the pump adds is what you get.

Fed by a city main. The pump adds on top of what already arrives, and the controller holds the total. Incoming pressure buys you more flow at the same setpoint.