34
Maximum Capacity Test
Flowbench capacity can be affected by such factors
as low line power, defective motor, a malfunctioning
motor controller, excessive leakage, and the local
elevation. This test determines the maximum flow
capacity of the flowbench.
When testing for maximum capacity, it is important
to know that the flowbench flow in rate cannot be read directly. Flow
pressure
must be used instead and
mathematically converted to Flow cfm.
Since we are setting the flowbench for an unrealistic test pressure set point well above its rated capacity
and
want to know the
actual
flow, follow the procedure below to test for maximum capacity.
1.
Remove any fixtures from the flowbench leaving only the large hole in the baseplate open.
2. Acquire a steel plate slightly larger than the baseplate opening to use for restricting the opening in the
baseplate.
3.
Set the flowbench to control to test pressure. Refer to section
"5.1.1 Setting the Servo Mode" on page
15.
4.
Set the flowbench to
Range 10
. Refer to section "5.1.4 Setting the Range" on page 17.
5. Obtain the
Full Scale Range Value
for range
10
. This information is on the calibration sheet shipped
with the flowbench or can be read from the flowbench reading r
egister
40022 FullScaleFlow
. It will
return the full-scale reading for the current flow range.
6. Set the
Leakage
to
0
(zero) according to the procedure in section "5.1.6 Setting Leakage" on page
18.
7. Set the your local system to display
Test Pressure
and
Flow Pressure
.
8. Set the
Test Pressure
for
100 inH
2
0
. Refer to section "5.1.2 Setting the Test Pressure" on page 16.
Always enter a value higher than what the
flowbench can reach with the test orifice wide
open. In this test the high test pressure set point
cannot be met because the hole in the baseplate is
too large.
NOTICE
9. Turn the motor ON. The motor will run at 100% trying to reach the high test pressure set point.
10.
Place the steel plate on the baseplate hole so that it barely restricts the flow.
11.
Slowly move the plate in to restrict the flow while watching the pressure readings. Notice that test
pressure slightly increases and the flow pressure decreases as the test orifice size is reduced.
12.
Continue to restrict the flow until the test pressure reaches 25 inH
2
0.
13.
Record the flow pressure.
14. Turn OFF the motor.
The motor on the flowbench runs
at full speed during this test. Wear
appropriate ear protection.
!
WARNING
6.0 Maintenance
