Dan answers a question out of Boston on flow limits and flow variance.
Here's the alert subscriptions process: Configuring Alerts
I would like to receive a notification from the controller when a program goes to run and there is no flow. How do I configure that in BaseManager?
In BaseManager → Flow Setup → Control Points
- Design Flow should be accurate based on the size of the master valve and flow sensor assigned to the control point.
- The High Flow Limit should be set to 16.7% more than the Design Flow.
- If “Shutdown” is enabled and a High Flow Limit issue occurs, the controller and zone valves will shut down.
- Mainline breaks, the control point is what allows the system to shut off flow through the mainline. If “Shutdown” is not enabled there will be an alert.
- Mainlines → Flow Setup → Edit.
- Design Flow is based on the size of the pipe.
- If Manage by Flowis enabled, the controller will choose which zones to run based on the total GPM capacity.
- Ex: it may run zones totaling 120 GPM to maximize the system capacity making it a great way to manage your water time and help your pump.
Flow Variance Limit
- Ex. If you set a straight flow variance limit at 20%, any time zones are running, the system checks if flow is within 20% of the expected value. So, if it expects 140 GPM or 40 GPM, and actual flow is 20% over or under, it sends an alert. If Shutdown is enabled, the controller will also stop watering.
- Ex: if you're running 260 GPM, the system compares that to the expected total from the running zones. Variance is always based on the expected flow, not the actual.
- The system may have a combination of zones, starting with 20 GPM drip zone, which could be all it can run, later on it might find 120 GPM or a mix of 100 GPM and 210 GPM zones.
- The % added should have the % variance decrease as the expected flow increases
- If controller is expecting 20 GPM (a really low flow), only allowing 30% variance before sending an alert.
- When dealing with a higher expected flow, like a large zone with 300 GPM, it might only allow 5% tolerance. Giving a narrow window, where a lot of damage can happen.
- Important to enable the “Shutdown” for high flow because there could be water running through a zone than expected.
- However, if someone shuts down our water source, we want to enable “Shutdown” for low flow, so we don’t have to run zones against that (alert and shutdown appear)
Common to have only an alert on high flow, because there’s a likelihood of something broken (sending an alert and shut down)
- However, if someone shuts down our water source, we want to enable “Shutdown” for low flow, so we don’t have to run zones against that (alert and shutdown appear)