Adjusting Convey Time and Dump Delay
Convey time is the length of time the station’s vacuum valve remains open to allow material to be drawn in. (For a
Dump delay is the length of time allowed for material to drain from the station into its receiver. During this time, the controller does not attempt to deliver any more material to the station.
The settings for convey time and dump delay should match the times actually required to fill and empty the station. The following problems may occur if these settings are incorrect:
1.Material is backing up and causing “high vacuum” alarms (for
2.System is not keeping up with the demand for material: Convey time is too short, or dump delay is too long.
For your reference, the Station n Operator screen shows the length of time the controller actually spent conveying material during the most recent delivery under Last Convey
Time.
To adjust a station’s convey time (or the dump delay):
1.Go to the Station n Operator screen (as described on p. 56), or go to the Station n Setup screen.
2.Touch Convey Time (or Dump Delay). A keypad pops up.
3.Enter the number of seconds desired. Use ← to erase any mistakes. Use ↵ to enter the value.
The new setting appears under Convey Time (or Dump Delay).
4.If you change convey time by more than a few seconds for a station with a remote proportioning valve (RPV), notify the setup personnel at your facility. The setting for the RPV’s cycle time should be adjusted to divide evenly into the new convey time (see page 41).
Activating and Stopping Priority Convey for a Station
Before activating priority convey, make sure that all other stations using the same pump have adequate material in reserve to continue operation. No material will be conveyed to these stations during priority convey.
If you want the controller to fill a specific station with material immediately, you can activate “priority convey” for that station. When you do so, the controller temporarily dedicates the station’s pump to it, ignoring demands from other stations assigned to that pump. Once the chosen station is full, normal operation resumes.
You can also use this feature to give one station a “head start” by conveying a few loads to it and then stopping the priority convey.
No more than one station for a given pump can be in “priority convey” at once. To activate priority convey:
Go to the Station n Operator screen (as described on p. 56), or go to the Station n Setup screen.
Chapter 4: Operation | 57 |