CH240 pH Digital Controller

pH Control Made Easy

The CHEMTROL® 240 pH Controller is a simple, easy to use controller designed to monitor and maintain the pH level in water. It is particularly adapted to the neutralization of acidic or alkaline solutions for environmental applications. A microprocessor-based digital controller, suitable in high-end residential pools, small commercial pools and spas and light industrial applications.


Standard Features

  • Easy to install, Simple to use
  • All Functions on Front Panel
  • pH control
  • Overfeed Safety Timer
  • Adjustable Set-point
  • Adjustable Alarms
  • Out-of-range alarms
  • Proportional Feed
  • Waterproof Cabinet
  • 5-year Electronics Warranty

The five LED lights indicate the operating mode (OFF, Manual or Auto), feed status, out-of-range alarms and overfeed alarms. The front panel controls include setpoint, calibration, low and high alarm limits, safety timer limit and proportional feed adjustment.
Feed control is either ON/OFF or Proportional. The Proportional Feed feature is particularly useful to avoid overfeeding in small bodies of water. It reduces the feed cycle time progressively as the sensor reading gets closer to the set-point.

CH240 Specifications

pH ControlAdjustable from 0.0 to 14.0
pH SensorGlass electrode with 3 m cable
ReadoutspH (2 digits) LEDs
Feed ModeManual, automatic, proportional
AdjustmentsSet-point, calibration, limits, feed rate
IndicatorsLEDs for feed mode, feed status, alarms
SafetyAudio, visual and remote alarms,
out-of-range limits and overfeed safety timers
CabinetPolystyrene 22 x 18 x 10 cm
Electrical230V or 24 VAC (specify)
Warranty5 years on electronic module

CH240 Installation

CONTROLLER

Connect the controller to 230V output of the Timer in parallel to the re-circulation pump.  This will prevent accidental feeding of chemicals when the pump is not running. Make sure to follow the electrical code.

SENSOR

Install the pH sensor on the re-circulation line or on the optional bypass line.  The sensor can be mounted directly on the main re-circulation line with a 2″ PVC tee, as shown on the schematic.  For re-circulation lines over 2″ in diameter lines, the sensor should be mounted on a 1/2″ bypass line.

CHEMICAL FEEDER

Connect the chemical feeder to 230V controller output, according to the manufacturer’s instructions, making sure to inject the chemicals downstream of the sensor. For a bromine or chlorine erosion feeder, install a corrosion-resistant solenoid valve on the intake line of the feeder. The controller is compatible with most ozonators and electrolytic generators.

CH240 Operation

The CHEMTROL® 240 pH Digital Controller automatically maintains the water pH level in pools and spas.

All operating functions are clearly labeled and accessible from the front panel, with many safety and easy-reset features not found on other controllers:

  • pH calibration from 4 to 10,
  • pH setpoint from 4 to 10,
  • feed modes: off, manual, automatic,
  • proportional control bandwidth from 0 to 100% of the setpoint,
  • pH high and low alarms from 4 to 10,
  • overfeed safety timer from 0 to 99 minutes.

To select a function, simply press pH and then the desired function.  The display shows the current function value.  Use the UP or DOWN arrows to adjust to the desired value.


Setpoint

The standard factory-set pH control level is 7.5  based on WORLD HEALTH ORGANIZATION (WHO) values for prevention of germs and bacteria.

To change the control level, press pH and then SETPOINT. Use the UP or DOWN arrows to adjust the pH setpoints. To save the new setpoint value and exit, press SETPOINT again.

The controller then automatically activates the chemical feeder for sanitizer feed, as required to maintain the set pH levels – regardless of fluctuations in bather load, contamination and weather. Like a thermostat maintaining a constant temperature, it prevents overfeeding or underfeeding, both of which are detrimental to good water quality.


Alarms

When there is an alarm condition, the corresponding display flashes the alarm value:

  • pH out-of-range,
  • pH overfeed.

The display stops flashing when the condition is corrected. To reset the overfeed timers, turn the feed mode to off and then back to Manual or Auto.


Reset

The ideal values are set as default values. They can be adjusted by the operator at any time. To reset all factory default values, press pH for 5 seconds.