microFLEX M2T Controller

Single Cooling Tower/Closed Loop Controller

The ProMinent® microFLEX is a cooling tower/closed loop controller that combines the latest technology with an economical solution.  Our breakthough design offers a worry-free thermal flow switch that does not require any user adjustments or calibration.

Request more info

Standard Features

  • Tower conductivity and temperature input
  • Flow switch status input
  • 5 Key universal keypad
  • 2 Line, 16 character backlit display
  • Single water meter input


  • Selectable Inhibitor Feed: Provides 4 feed modes; bleed and feed, bleed then feed, proportional to makeup water volume and percentage time.
  • Water Meter Input: Allows for chemical to be fed based on water volume versus timed pump control methods generally found on comparably priced controllers.
  • Single Point Calibration: For ease of start up and operation. Warning message immediately detects fouled or faulty sensors.
  • What and Why Information: On the controller display is a valuable troubleshooting tool. Solenoid and chemical pump relays show complete status. Shows WHY the relay is on/off.
  • Controller Run Time: Gives total hours per day and total operating days since initial installation.
  • Robust Diagnostics: Provide complete 24-hour history of bleed valve operation, relay run times and minimum/maximum temperatures.
  • Keypad Password: Eliminates unauthorized adjustments.
  • Communication Options: Include Ethernet networking, dry contact alarm relay or 4-20mA output on conductivity.
  • Optional Web Browser User Interface with Networking Capabilities: Provides ability to direct connect to the controller from a portable workstation, such as a laptop computer. Can also view critical processes remotely through the use of a LAN.

Image Download

Note: Click on image to download


Rating - Detail Notes
Analog-Digital I/O
Conductivity Sensor Auto ranging from 100uS to 10,000uS compensated Single point calibration, temperature
Temperature Sensor 32oF to 125oF (0oC to 50oC) Displayed as F or C
Thermal Flow Switch 1GPM trip within 30 seconds NO FLOW Typically 10 second trip with in FLOW/
Water Meter Input current 400Hz, 0.5mA @ 5VDC measurement head Accepts paddlewheel or contacting
Relay Outputs 1 SPST (Inhibitor), 1 SPDT (Bleed) Single controller fuse
4-20mA Output (optional) Single DC isolated, loop powered loop User definable span, alarms on open
Alarm Relay (optional) un-fused 500mA @ 24VDC Dry contact set, alarm Normally closed contact, open on
Communications User Interface
Keypad-LCD 5 Key tactile feedback, universal characters, 2 line x 16 character, backlit Scan rate 100 mS nominal, User adjustale contrast
10 Base T, TCP/IP Ethernet LAN(optional) HTML micro web server with user definable IP address User definable static IP Remote Monitoring & Programming
Relay ON/OFF ON/OFF control valve Relay 1 chemical feed, Relay 2 bleed
Volumetric feed User set, measure volume & pump on time Sequential control, measures make-up volume then bleeds for user set volume
Interlocking Flow switch contact set input Relays OFF when contact set opens
Blocking Inhibitor feed may be set to block on bleed
Alarms - Feed Limit Timers Minutes per day Auto-reset @ Midnight
Units of Measurement US/Metric selectable Option to use US or Metric units of measurement
Electrical 120VAC, 50/60Hz
Internal Fusing 5 AMPS @ 120VAC
Surge Suppression Relay 2 N.O. (bleed) contacts snubbed @ 0.1uF, 150ohm Varistor on AC line input
Accessory Power 15-22VDC, unregulated, thermally fused @ 50mA
Enclosure Non-metallic, NEMA 4X 5.9”W x 5.9”H x 3.5”D (150mm W x 150mm H x 90mm D)
CSA: Pending CSA tested to comply with UL (Pending)


Download Zip File With Controller Accessory Documents | Part #: xxxxxx | Updated: 4/2/14

Application Notes

Application Notes: "Snubber" Explanation | Part #: xxxxxx | Updated: 5/29/13
How To Setup Computer IP Address | Part #: xxxxxx | Updated: 10/12/12
Preventative Maintenance Cooling Tower Sensors | Part #: xxxxxx | Updated: 4/18/06

Boiler & Cooling Tower Instructional Videos

Video: Cooling Tower & Boiler Controllers II: Communication Options (WEBINAR) | Part #: xxxxxx | Updated: 1/24/14
Video: Inputs/Outputs & Hardware For Boiler & Cooling Tower Controllers (WEBINAR) | Part #: xxxxxx | Updated: 11/8/13


Cut Sheet: MicroFLEX Single Cooling Tower | Part #: 7750305 | Updated: 8/17/21


Trackster | Part #: Version 3.2.5385 | Updated: 10/22/14

Installation And Wiring

Cradlepoint CTR500 Setup | Part #: xxxxxx | Updated: 7/19/13

Product Catalog Full Version

Catalog: 2023 Product Catalog - Full Version | Part #: 7750257 | Updated: 3/3/23

Product Catalog Section

Catalog: 2023 Product Catalog - Pumps & Systems Accessories Section | Part #: 7750257 | Updated: 3/3/23
Catalog: 2023 Product Catalog - DULCOMETER, Cooling Tower & Boiler Controller Section | Part #: 7750257 | Updated: 3/3/23

ProMinent Helps Video

Video: ProMinent & Cranberry Township Wastewater Treatment Plant | Part #: xxxxxx | Updated: 4/10/19

Sensor Instructional Videos

Video: Changing Electrolyte In Sensors | Part #: xxxxxx | Updated: 7/28/21

Sensor Specifications

MicroFlex Cooling Tower | Part #: xxxxxx | Updated: 4/2/14

Technical Manual

Technical Manual: Boiler Sensor Test Procedure | Part #: xxxxxx | Updated: Unknown
Technical Manual: How To Connect To Controllers | Part #: xxxxxx | Updated: Unknown
Technical Manual: How To Connect To Controllers (Power Point) | Part #: xxxxxx | Updated: Unknown
Technical Manual: How To Setup Computer IP Address | Part #: xxxxxx | Updated: 10/12/12
Technical Manual: How To Setup Computer IP Address (Power Point) | Part #: xxxxxx | Updated: Unknown
Technical Manual: Optional Wireless Communications EvDO | Part #: 7750312 | Updated: 6/27/13
Troubleshooting Via Hyper Terminal | Part #: xxxxxx | Updated: 1/1/09
Troubleshooting Via Hyper Terminal (Power Point) | Part #: xxxxxx | Updated: 1/1/09