Grundfos Hydro MPC-E CRE Variable Speed Booster System

Hydro MPC-E is Grundfos’s packaged booster system for commercial buildings and water supply: two or three identical CRE vertical multistage pumps in parallel on a stainless steel base frame, with manifolds, valves and a control cabinet, ready to connect. Every pump has its own permanent-magnet MLE motor with an integrated frequency converter, and the CU 352 controller holds a constant outlet pressure by adjusting the speed of the pumps and cutting pumps in and out as demand changes. All running pumps run at the same speed. These builds have the control cabinet on its own base frame (design D), which can stand up to 6.5 ft from the pumps.

• Constant-pressure control with automatic cascade, plus proportional-pressure control and alternative setpoints
• Automatic pump changeover by load, operating hours and fault; standby pump and emergency run functions
• Stop function at low demand, specific energy calculation and a log of system performance
• MLE motors to 15 HP with a combined drive and motor efficiency above NEMA Premium
• Ethernet as standard; BACnet MS/TP, Modbus RTU, LonWorks, PROFIBUS DP or cellular remote management through a CIM module

Every pump is a working pump and a backup. The CU 352 alternates the pumps by load, running hours and fault, so wear is shared and a pump that alarms is replaced in service by the next one. At peak demand all pumps run together for the full system flow; at low demand one pump carries the load and the others stop.

Find your system, then read across: each figure is the pressure the system adds, at maximum pump speed, at that total flow. The controller runs the pumps anywhere below these curves to hold your setpoint, so a system covers your duty if its figure at your peak flow is at or above the boost you need.

Hydro MPC with CRE 10 — pressure added in PSI

Curve ends: 2 x CRE 10-4 138 GPM; 2 x CRE 10-6 138 GPM; 3 x CRE 10-4 207 GPM; 3 x CRE 10-6 207 GPM. Derived from Grundfos’s single-pump curve in the Grundfos Hydro MPC data booklet, 60 Hz North America, p. 39, at 2x and 3x the flow; Grundfos publishes no combined curve for these 60 Hz builds. Digitized and rounded down.

Hydro MPC with CRE 15 — pressure added in PSI

Curve ends: 2 x CRE 15-2 250 GPM; 2 x CRE 15-4 250 GPM; 2 x CRE 15-5 250 GPM; 3 x CRE 15-2 375 GPM; 3 x CRE 15-4 375 GPM; 3 x CRE 15-5 375 GPM. Derived from Grundfos’s single-pump curve in the Grundfos Hydro MPC data booklet, 60 Hz North America, p. 40, at 2x and 3x the flow; Grundfos publishes no combined curve for these 60 Hz builds. Digitized and rounded down.

Hydro MPC with CRE 20 — pressure added in PSI

Curve ends: 2 x CRE 20-2 308 GPM; 2 x CRE 20-4 308 GPM; 3 x CRE 20-2 462 GPM; 3 x CRE 20-4 462 GPM. Derived from Grundfos’s single-pump curve in the Grundfos Hydro MPC data booklet, 60 Hz North America, p. 41, at 2x and 3x the flow; Grundfos publishes no combined curve for these 60 Hz builds. Digitized and rounded down.

Hydro MPC with CRE 32 — pressure added in PSI

Curve ends: 2 x CRE 32-2-1 422 GPM; 2 x CRE 32-3-2 422 GPM; 3 x CRE 32-2-1 633 GPM; 3 x CRE 32-3-2 633 GPM. Derived from Grundfos’s single-pump curve in the Grundfos Hydro MPC data booklet, 60 Hz North America, p. 42, at 2x and 3x the flow; Grundfos publishes no combined curve for these 60 Hz builds. Digitized and rounded down.

Flows are the points nearest 20%, 50% and 75% of the triplex curve end, then that end. Bold = the last column that system’s curve reaches; — = beyond it. Pressure added in PSI = feet of head ÷ 2.31. Losses in fittings and valves are not included. Some curves rise a little before they fall, so a figure can sit just above shut-off. Grundfos draws its own Hydro MPC CME system curves the same way, at N times the single-pump flow.

• In buildings, fit the diaphragm tank Grundfos requires for the stop function, sized from the table in the data booklet.
• Match the dry-running protection to the inlet: a pressure switch or transmitter on a pressurized inlet, a level switch or electrode relay when drawing from a tank or well.
• The control cabinet stands on its own base frame and can be placed up to 6.5 ft from the pumps.
• Each pump can be removed without disturbing the piping on either side of the manifolds.

From the Grundfos Hydro MPC data booklet, 60 Hz North America.

Domestic water pressure boosting and high-rise buildings, municipal water supply and transfer, hydronic (HVAC) circulation and redundant pumping duties.

The system is set up and run from the CU 352 controller on the cabinet door, with no app required. Grundfos GO adds live operating data, alarm troubleshooting and reports on a smartphone, talking to the pumps by infrared or radio through Grundfos GO Remote. Grundfos lists the MI 301 mobile interface for this; it is sold separately.