Model 140 Cooling Tower TDS Controller

The Model 140 has three outputs for simple system operation when straightforward automation is all you need.
cooling tower tds controller

Sometimes simpler really is better – and the Model 140 Cooling Tower TDS Controller provides basic cooling tower automation. Featuring three output relays (typically one for bleed and two for chemical feeds), the cooling tower controls provide simple-to-follow programming to make your on-site time efficient.

Inputs include conductivity, one flow switch, and one water meter. The NEMA 4X enclosure opens wide for easy wiring and troubleshooting.

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The Model 140 TDS Controller for cooling towers can control conductivity plus two chemical feeds.

Controller inputs include one water meter, conductivity, and one water flow sensor switch. The three output relays are rated at 3 amps each with a total of 10 amps maximum. Further, there is a 4-20 mA output you can use to send the system conductivity to a monitoring system.

Lakewood’s Cooling Tower TDS Controller is available as the controller alone, or configured with conductivity, water flow sensor switch, plumbing, or on a mounting plate. Lakewood makes your job easier. System setup for the cooling tower controls are easy using the menus already on board, with simple directions and options. Blowdown your system with setpoint control, and manage the other relays based on blowdown percent, water meter inputs, or even biocide feed schedule with up to six feeds programmable. Further, relays 2 & 3 can be programmed as alarm relays to notify you in case of an excursion.

Want to go to the next level? Pair your 140 Cooling Tower TDS Controller with Lakewood’s OnSight Remote Access System to get remote monitoring capability including data logs and graphs from anywhere, anytime. The OnSight System gives your customers peace of mind that you are on top of water treatment, even if they don’t want you on their site.


  • Type: Model 140
  • Includes: Optional sensor and plumbing configurations
  • Output Relays: 2 selectable use and 1 blowdown relay
  • Flow Switch: Flow switch input
  • Water Meter: 1 water meter (contact head, paddle wheel or turbine) input
  • Output Signal: 1 isolated or non-isolated optionally powered 4-20 mA output
  • Mounting plate: Optional mounting plate
  • Conductivity Range: 0 – 10,000 μS
  • Temperature Compensation: 500 ohm NTC
  • Ambient Temperature: 32° – 120° F (0° – 49° C)
  • Sensor Type: 2 electrode conductivity sensor
  • Conductivity Resolution: ± 10 μS
  • Accuracy & Repeatability: ± 1.0%
  • Deadband/Setpoint: Adjustable
  • Enclosure: NEMA 4X, ETL
  • Timer: Max. blowdown time exceeded, relay runtime exceeded
  • Power: 120/240 VAC 50/60 Hz
  • Relay Ratings: 3A each, 10A total
  • Usage: Water treatment conductivity control


  • Easy to program with the user-friendly menu interface.
  • Scheduled feed, which can use two relays for biocides or other chemicals.
  • Ball valve delay feature allows accurate control of motorized ball valves.
  • One (1) water meter input, conductivity input, flow switch input, and 4-20 mA output are all standard features.
  • Removable power cord and receptacles for simple conduit installations.
  • Onboard selector switch for 120 or 240 VAC power.
  • LED indicators for power, alarm and relay status.
  • Designed with a single circuit board for better reliability and lower cost.
  • Large open shallow enclosure for easy wiring.
  • The enclosure is rated NEMA 4X.
  • Heavy-duty stainless steel domed numeric keypad and illuminated graphical display allow for quick and easy programming. Steel domed switches improve the tactile sensing and life expectancy of the keypad.


  • Reliable cooling tower conductivity control at a low cost.
  • Easy to program with the Lakewood plain English, intuitive, and user-friendly menu interface.
  • Single circuit board design improves reliability.

Product Documentation

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