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1.0 Introduction
The DC4500 is a microprocessor-based conductivity controller. It is designed for use in a variety of water
treatment applications requiring precise control of totally dissolved solids and chemical feed. Among its many
uses, the DC4500 will control conductivity and chemical feed in cooling towers and closed loop systems.
LMI’s DC4500 Series of conductivity controllers allows the greatest programming flexibility for cooling tower
system applications. This is accomplished through the use of an extensive options menu that is easy to use.
BLEED or BLOWDOWN of system water by valve control can be based on several setpoint options:
• Conductivity setpoint
• Hysteresis delay (lower than setpoint) to avoid valve operation chattering
• Rising or Falling conductivity trip points
FEED of chemical (inhibitor) can be based on four (4) different methods and the pump control can be either
On/Off or externally-triggered Variable Speed.
• FEED at the same time system BLEEDS (lockout timer limits maximum FEED time)
• FEED time calculated as a percentage of total BLEED time
• FEED based on a timed cycle (pump is on for a percentage of this timed cycle)
• FEED based on flow meter input
DUAL BIOCIDE chemical addition may be accomplished by the use of two (2) individually programmable
relays or optocoupler outputs. These outputs provide control of two individual chemical addition pumps based
on the following options:
• On/Off or externally-triggered Variable Speed pump control or BOTH for two pump/TIMER operation
• 28-DAY programmable timer (1, 2, 3, or 4 week selectable cycle)
ALARM indicators and relay outputs are energized based on the following conditions:
• HIGH conductivity set point is reached
• LOW conductivity se tpoint is reached
• NO FLOW condition exists (flow switch must be installed)
The display is a 16-character backlit LCD (liquid crystal display) which is visible in all light conditions.
A three-key position membrane is used to enter data and settings (see Figure 1).
The conductivity range is 0 - 20,000
µ
Siemens. The units can be either
µ
Siemens or PPM/TDS (total disolved
solids).
(866) 433-6682 • (281) 359-8538 • [email protected] • www.novatech-usa.com
