Walchem WBLW100 Series Instruction Manual - page 23
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5.3.11
Relay or Analog Output, Manual Mode
Output Details
The details for this type of output include the relay on/off state or analog output %, HOA mode or Interlock status,
accumulated on-time, alarms, current cycle on time and relay type.
Settings
A Manual relay will activate if the HOA mode is Hand, or if it is Activated With another channel. There are no addition-
al programmable parameters.
5.3.12
Relay, Pulse Proportional Control Mode
ONLY AVAILABLE IF W120 MODEL/POWER RELAY BOARD IS INSTALLED
Output Details
The details for this type of output include the relay pulse rate, HOA mode or Interlock status, accumulated on-time,
alarms, current cycle on time and relay type.
Settings
Press the Settings key view or change the settings related to the relay.
Set point
Enter the sensor process value at which the output will pulse at the Minimum Output %
set below.
Proportional Band
Enter the distance that the sensor process value is away from the set point beyond which
the output will be pulsing at the Maximum Output % set below.
Minimum Output
Enter the lowest possible pulse rate as a percentage of the Maximum Stroke Rate set
below (normally 0%).
Maximum Output
Enter the highest possible pulse rate as a percentage of the Maximum Stroke Rate set below.
Maximum Rate
Enter the maximum pulse rate that the metering pump is designed to accept (10 - 360
pulse/minute range).
Input
Select the sensor to be used by this relay.
Direction
Set the control direction.
5.3.13
Relay, Dual Set Point Mode
Output Details
The details for this type of output include the relay on/off state, HOA mode or Interlock status, accumulated on-time,
alarms, current cycle on time and relay type.
Settings
Press the Settings key view or change the settings related to the relay.
Set point
Enter the first sensor process value at which the relay will activate.
Set point 2
Enter the second sensor process value at which the relay will activate.
Deadband
Enter the sensor process value away from the set point at which the relay will deactivate.
Duty Cycle Period
Using a duty cycle helps to prevent overshooting the set point in applications where the
response of the sensor to chemical additions is slow. Specify the amount of time for the
cycle, and the percentage of that cycle time that the relay will be active. The relay will be
off for the rest of the cycle, even if the set point has not been satisfied.
Enter the length of the duty cycle in minutes:seconds in this menu. Set the time to 00:00 if
use of a duty cycle is not required.
Duty Cycle
Enter the percentage of the cycle period that the relay will be active. Set the percentage to
100 if use of a duty cycle is not required.
Input
Select the sensor to be used by this relay.
Direction
Select the control direction. In Range will activate the relay when the input reading is
between the two set points. Out of Range will activate the relay when the input reading is
outside the two set points.
5.3.14
Relay, Probe Wash Control Mode
Basic Timer Operation
When a Probe Wash event triggers, the algorithm will activate the relay for the programmed time. The relay will
activate a pump or valve to supply a cleaning solution to the sensor or sensors. The output of the selected sensors will
either be held or disabled during the cleaning cycle, and for a programmable hold time after the cleaning cycle.
Special Condition Handling
Overlapping timer events
If a second timer event occurs while the first one is still active, the second event will be ignored. An Event
Skipped alarm will be set.
Interlock Conditions
Interlocks override the relay control, but do not change the operation of the timer control.
A digital input or output interlock condition does not delay the relay activation. The relay activation duration
timer will continue even if the relay is deactivated due to an interlock condition. This will prevent delayed
events which can potentially cause problems in they do not occur at the correct time.
“Activate With” Conditions
“Activate with channels” settings override the relay control, but do not change the operation of the timer
control. The relay activation duration timer continues counting when the timer relay is forced on, and ends at the
expected time (event start time plus duration). If the “activate with” condition continues after the end of the event
time, the relay remains activated.
Alarms
An Event Skipped alarm is set when a second timer event occurs while one event is still running. An Event
Skipped alarm is also set when the timer relay never turns on during an event because of an interlock condition.
The alarm is cleared when the relay is next activated for any reason (the next timer event or HAND mode or
“activate with” force on condition).
Output Details
The details for this type of output include the relay on/off state, HOA mode or Interlock status, accumulated on-time,
alarms, current cycle on time and relay type. The current week number and day of the week is displayed (even if
there is no multi-week repetition event programmed). Cycle Time shows the time counting down of the currently
active part of the cycle.
Settings
Press the Settings key view or change the settings related to the relay.
Event 1 (through 10)
Enter these menus to program timer events via the menus below:
Repetition
Select the time cycle to repeat the event: Hourly, Daily, 1 Week, 2 Week, 4 Week, or
None. An event means that the output is turned on at the same time of day, for the same
amount of time, and except for the Daily cycle, on the same day of the week.
Week
Only appears if Repetition is longer than 1 Week. Select the week during which the event
will occur.
Day
Only appears if Repetition is longer than Daily. Select the day of the week during which
the event will occur.
Events Per Day
Only appears if Repetition is Hourly. Select the number of events per day. The events
occur on the Start Time and then evenly spaced throughout the day.
Start Time
Enter the time of day to start the event.
Duration
Enter the amount of time that the relay will be on.
Input
Select the sensor that will be washed.
Input 2
Select the second sensor, if applicable, that will be washed.