Flow Switch Plumbing Installation
s
WARNING
!
Hazardous Pressure Present: Pressure at the flow switch must be limited according to the water
temperature that the flow switch will see in service. Note that this includes the temperature
that the water could reach due to heating by the surrounding environment. Pressure at the
flow switch must be limited according to the following table.
Maximum Water Temperature (°C)
NOTE: Pressure at the flow switch can be reduced by eliminating plumbing restrictions including
reductions in pipe diameter downstream of the flow switch.
On the F21 paddle style flow switch, the paddle must be trimmed to allow it to fit into the plumbing.
The paddle should be trimmed so that it is as long as possible, but not closer than 4 mm (.160"), to the
pipe walls when installed. A longer paddle length will increase flow switch sensitivity and therefore
water delivery at low power conditions. Additional installation instructions including mounting
orientation, paddle trimming, other plumbing requirements, etc. are included with the flow switch.
Follow the installation instructions included with the packaging of the flow switch for installation and
maintenance information.
Flow Switch Operation
At start-up, the flow switch naturally detects no flow. If the flow switch detects flow before the
controller starts the motor, then the flow switch wiring is faulty or the paddle is stuck and the
controller stops, displaying an E4 error. The state of the switch must show no flow in order for the
drive to attempt to start. After the controller starts the motor, it expects the flow switch to detect
flow within an interval that depends on power being delivered. If the flow switch detects flow within
that interval, then the controller operates normally. If the flow switch does not detect flow, the
controller enters a deadhead mode, displaying E4, and alternately runs the motor and pump, then
allows them to cool.
The time intervals during deadhead mode depend on the power being provided by the controller. For
power less than 1200 Watts, the overall repeat time interval is approximately 11 minutes. For power
greater than 1200 Watts, the repeat time interval is approximately 14 minutes. The run-time and cool-
down portions within each repeat time interval are controlled to limit the total energy supplied to
the motor/pump within each interval, and are thus dependent on the controller output power.
18
Flow Switch Pressure Rating vs. Water Temperature
20
25
30
35
40
45
50
55
60
Table 1: Flow Switch Pressure
Gauge Pressure (bar)
18
15.75
13.5
11.25
9
6.75
4.5
2.25
0
Gauge Pressure (psi)
261
228
196
163
131
98
65
33
0