ROLA-CHEM Digital Controller PN 554135 5/04/2017 Page: 5 of 20
3. Description and Specifications
3.1 General Description
The controller is a microprocessor-based chemical automation system which continuously
monitors and maintains the pH balance and sanitizer level in a swimming pool or spa.
The pH and sanitizer level (ORP) are displayed using sun-bright seven-segment light emitting
diodes. The pH and ORP levels are continuously monitored and displayed on the controller’s
front panel. The ORP/pH controller has been designed to be user friendly. One MODE button
and six SET buttons allow the operator to easily set parameters.
The pH display range is 6.0 to 8.4 with a .1 unit resolution. The pH set point is adjustable
from 7.0 to 8.0 in .1 pH steps with a factory default set point of 7.4 pH. During a pH feed
cycle, the pH feed lamp will blink when pH chemicals are being fed and illuminate
continuously during the feed delay portion of the feed cycle. The pH Alert lamp will illuminate
when the pH reading is higher or lower than the high and low pH Alert set points and prevent
the feeding of pH chemicals.
The sanitizer (ORP) display range is 0 to 995 mV with a 5 mV display resolution. The ORP
set point is adjustable from 400 to 900 mV with default set point of 650 mV.
During an ORP feed cycle, the ORP feed lamp will blink when sanitizer chemicals are being
fed and illuminate continuously during the feed delay portion of the feed cycle. The ORP
Alert lamp will illuminate when the ORP reading is higher or lower than the high and low ORP
Alert set points and prevent the feeding of sanitizer chemicals.
A manual feed cycle for pH or ORP can be started by pressing the MODE button (placing the
controller in stand-by mode for either pH or ORP) and then pressing the FEED ONCE button.
The feed cycle is a timed-based ‘feed then delay’ system. The controller has a series of fixed
feed times (0.6 to 900 sec.) with associated delays as well as a Continuous feed mode. A
feed cycle consists of a feed time plus a delay time. Example: a 30 second feed time
followed by a five-minute delay would have a 5½ minute feed cycle. The chemical feeder
dispenses chemical only during the feed time portion of the cycle and then waits for a delay
period to allow for chemical to dispense throughout the swimming pool or spa.
The controller incorporates an internal non-volatile memory in which all factory default
settings as well as field-modified settings are stored. The internal memory is not affected by
power interruption and requires no backup battery. Acid/base, pH/ORP interlock, function
control and lockout switches are located behind the terminal block access panel.
The pH and ORP outputs are capable of handling 5 amps each at 120 Volt AC. The relay
outputs are fused and transient protected. An internal terminal strip is provided for field wiring
of the controller. The internal step-down transformer has a class-two energy limiting rating to
provide for electrical safety.
