Retrotec Commercial 441 and 451 DucTester - Manual (Page 54)

Page 54 of 56
©Retrotec Inc. 2015
Appendix E: Troubleshooting
Occasionally simple problems do occur with a DucTester system. If the problem is described in any of
the following sections, follow the steps to attempt to resolve the problem. If the problem persists,
contact
[email protected] .
“--” appears on display:
Backpressure refers to the pressure that the DucTester fan works against while running. Under most
testing conditions, backpressure is not a concern. If the backpressure is too great, the DM32 gauge will
automatically sense it and display “--“, indicating the fan pressure signal is too low compared to the
pressure the fan is working against. Changing to a more restrictive Range Configuration will solve this
problem.
Gauge “Flow” reading does not change? Turn off [@]
When the measured flow or fan pressure does not increase as fan speed increases the gauge has likely
been set to calculate a value for result extrapolation. To remove result extrapolation, press the [@]
button until “is Off” is shown.
If [@] is active, the gauge calculates a reading for flow at the extrapolation pressure, no matter what the
actual “PrA” measures. Therefore, regardless of fan speed, the measured flow will appear relatively
unchanging.
Fan does not run
Make sure the power light is on and the power switch is set to “1”. If the yellow Speed Control Cable
(Ethernet-style) has been connected previously to a gauge, the Speed Control Knob must be turned off
and then on again. This is a fail-safe feature so the fan does not go on unless you want it to.
Alternatively, turning the power switch off and back on will activate the Speed Control Knob as long as
the Speed Control Cable is not connected.