961-20A0-010 Datasheet, PDF (29/36 Pages) Magnetrol International, Inc. – Ultrasonic Single and Dual Point Level Switches

PROBLEM
No signal with level change
No change in output between
wet gap or dry gap
The switch is chattering
Two flashes of the LED indicates an issue with the elec-
tronics module. Contact the factory for a replacement
electronics module. See Section 3.8 for spare electronics
module part numbers.
Environmental noise is the issue if the diagnostic LED
flashes three times. Common sources of environmental
noise are conducted electrical noise from a VFD (variable
frequency drive), radiated electrical interference from a
two-way radio transceiver, or mechanical vibration from
some nearby source. This noise could affect the 961/962
and other electrical instrumentation. Check to see if any
of the above listed sources may be causing the interference
and correct the issue to ensure proper operation of the unit.
It is also possible that application related issues may be
affecting the proper operation of the 961/962 unit. The
table below assists in troubleshooting.
ACTION
Check wiring to make sure proper input voltage is supplied.
Make sure liquid is reaching the gap. If installed in a riser or standpipe, make sure a
vent is provided such that liquid can enter the pipe and wet the transducer gap.
Check for dense foam on surface or dried product in the gap.
Unit may not function properly if either condition exists.
Check to see if transducer gap is plugged with solids.
Check for dense foam in gap.
Check for proper input voltage supply.
Check for turbulence. Relocate switch or isolate from turbulence.
Check for excessive aeration.
51-646 Echotel^® Model 961 & 962 Ultrasonic Level Switches
29