Low Level Sensor Calibration; Low-Level Sensor Led Indicators And Trouble Shooting - Graco PR70 Manual

On-Board Polyethylene Feed Systems
Be careful when reaching into the tanks to verify that the sensors are
functioning. Read all manufacturer's warning and material MSDS to know the
specific hazards of the material used. Wear respirator, gloves and other
protective clothing as necessary before dispensing material.

Low Level Sensor Calibration

8. After plugging in the harness, locate the TEACH
ELEMENT in the area called out in the illustration to
the right. It will be marked with a "bullseye."
A. Activate the teach element by holding a
screw-driver near the bullseye. Only hold the
screw-driver there until the GREEN LED
begins flashing, but no more than five (5)
seconds
B. After a short time, the GREEN LED will stay lit
continuously.
C. You are now in OPERATING MODE for that
sensor. Repeat with the other sensor.
9. If the tank is clean and you wish to check the sensor
and make sure it's working before dumping material
in, you can simply reach your hand down inside the
tank and touch the tank wall in the sensor area. A
GREEN and YELLOW light illuminated at the same
time means the sensor is detecting your hand.
10. If the tank is empty, but not clean, please refer to
your MSDS sheets to determine what protective
measures must be taken before reaching into the
tank.
11. Please refer to manual 312393A for instructions on
interfacing the new sensors with your machine's
HMI

Low-Level Sensor LED Indicators and Trouble Shooting

Green LED
• ON = Unit is ready for operation
• Flashes Slowly (1Hz) = Adjustment mode in empty state
• Flashes Quickly (2Hz) = Adjustment mode full state
•
Yellow LED
• OFF = Switching output disabled
• ON = Switching output enabled
Red LED
• ON = close to reaching the switching threshold
• Flashes Quickly (8Hz) = Adjustment Error, Internal Fault
Red & Yellow
• Flashing Quickly (2Hz) simultaneously = Short Circuit in the switching output
LED's Together
Please note that the RED LED DOES NOT INDICATE MALFUNCTION of the unit. It indicates that the internal
sensor signal is near the switching threshold
312394B
OFF = Locking mode
Figure 6: Low Level Sensor Calibration
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