To resolve unexplained shut downs, investigate the following:
- Grainflow Timer
- Linear Limits
- VFD (fault code on screen)
- Soft starter (fault code on screen)
- CAL temperature controller for low or high alarms
- Check spring block terminals to make sure wire is engaged in terminal block securely.
- Check to make sure that shielded ground is landed properly to ground.
When running hard conduit from the high voltage cabinet to the remote cabinet, why do I have to run two separate conduits?
- The signal , Ethernet, communication and thermocouple cables are all vulnerable to noise, induction and signal loss. The best way to protect this wiring from issues is to separate it from any voltage above 24 volt. The 120 volt AC control wiring should run in separate conduit from signal wiring for best results.
- Make certain the cables are all grounded on one end to reduce potential interference.
- The standard remote length is 20′ because it represents the maximum run before the noise, induction and signal loss become a problem.
- Check to see if wire is landed in terminal block properly and not clipped onto insulation instead of wire.
- Check to make sure wire is in properly marked terminal for wire number. Wire number and terminal block number should always match.
- If you have Pinnacle LITE, make this your first step: Select PLC I/O on the tool bar. With the power control switch in the ON or first position, refer to the left hand column on the Inputs page. The uppermost item that is white instead of green is where you begin checking.
- Dryer does not have or has lost the neutral leg to control circuit
- Measure voltage from neutral to ground, if voltage is present check transformer to make sure neutral is bonded to ground. This is a floating neutral and we do not want this condition on this equipment.
- Relay or timer is not seated in holder or socket.
- Wire in safety circuit is not properly landed in terminal block.
- Check rear door, high limits and motor control resets
- Disconnect is not energized.
- Manual motor protector breaker is not turned on.
- No power to stop and start switch.
- Check for proper voltage across lines and line to ground.
- Motor is bad, replace motor. Motor leads can be checked for continuity using voltage meter and trained electrician.
- Motor rotor has seized and motor is in locked rotor condition, this will generate very large amp draw and hold amp draw until breaker trips. Replace motor or have motor re-worked by motor shop.
- The board is 120-volt input to operate and dc voltage to control VFD or SCR for metering system. Check 120-volt input voltage to make sure it holds steady.
- Output voltage should remain from 0-12.5 DCV output to control discharge speed to device.
- Disconnect wires from output +/- and check for DC voltage, if input is good than output should be able to measure DC voltage as you adjust potentiometer. If you cannot read any voltage replace board.
- Adjust moisture control potentiometer and switch from plus to minus lights on and off. If you cannot adjust lights check to see if board is powering on each light as you turn pot.
- Can you adjust speed of motor? If you turn potentiometer the resistance should change from 0-5K, if it does not replace potentiometer.
- If lights will both come on at same time, turn potentiometer located on board labeled dead band. Rotate until one of the two lights goes out and other remains on.
- If speed of drive will not control and simply runs all the way open 100% or all the way closed to 0 speed, the potentiometer is most likely lost one lead and can be checked for continuity on each line, replace the potentiometer.
The air pressure switch receives power on one side of terminal once fan contact is energized and fan is running. The dryer must be full of grain to create required air pressure to satisfy switch.
- If light is not ON and fan is running, check to make sure that adjustment on switch is all that might be needed to energize air pressure light.
- If adjustment is not enough to energize switch, then check air pressure light by jumping terminal at air pressure switch. If light does not come on check wiring to switch and to light. Does light work when energized?
- Disconnect wires from switch and unscrew switch from tube. While fan is running can you feel air from chamber coming out of tube port? If not clean out tube and/or clean off filter inside chamber on opposite end of tube.
- If air is feeding into switch and air pressure switch is not making and one side of terminal is 120 volts, then make sure opening on switch has plug with small orifice to create low pressure side. Make sure nothing is internally wrong with diaphragm. Make sure diaphragm is not frozen solid. Replace air pressure switch.
- If the safeties of the auxiliary equipment are connected to C5 & C6, check out the auxiliary equipment.
- Possible defective whisker switch (Profiles), mercury switch (Older profiles), or rotary bin switch (Towers).
- Check for proper line voltages on all three legs.
- Check for proper belt tension.
- Investigate for worn bearings on both fan and motor.
- Try opening or closing louvers on the air doors.
- Replace the shutdown delay timer relay.
The VFD does not run, even in local control. I have the proper voltage to the VFD and the keypad is illuminated. How do I fix?
- Check the 24vdc circuit breaker in the high voltage cabinet. Use a voltmeter to verify 24vdc is present.
- Replace the shutdown delay timer relay.
- Check the mid grain RTDs and transmitters for shorts.
- Check the moisture sensors for shorts.
Why on the CAL temperature controller and on the HMI screen, the plenum temperature is a negative number when it is obviously not that cold.
- Check connections of the signal wires to the RTD or Thermocouple, at the terminal blocks, and at the CAL.
- Possible bad RTD or thermocouple.
The plenum temperature as shown on the HMI and on the CAL controller does not seem accurate. What’s the fix?
- Use a temperature testing device and place its probe in the same place as the dryer’s RTD or thermocouple and observe the difference.
- When the dryer is empty, the temperature shown on the CAL or HMI should be within a few degrees of actual ambient. Be aware that the sun shining on the dryer can cause some difference.
- If the difference is more than a few degrees, replace the RTD or thermocouple.
My older dryer sometimes shuts down for no apparent reason. I can start back up again without resetting anything. How do I resolve this?
- Check adjustment and operation of discharge overload door switch. Grain can back up in the take away, lifting the door, opening the switch, and killing the dryer. By the time you investigate, the grain has settled and allowed this door to close. If the dryer discharge is connected to an air system, look for back pressure to hold up or bounce the overload door, triggering a shutdown.
- If the dryer is equipped with an Omron brand grain flow timer, replace it with kit PN 1289040.
- If it is an older dryer, the mercury switch on the overload door might need replacing.
Clear the fault codes by turning off power to the VFD and then back on.
- Verify that the 24vdc circuit breaker in the high voltage cabinet is on.
- Check that there is 24vdc to the RTD transmitters. On current models, this transmitter is in the well on the individual RTD. On older dryers, all four transmitters were in a box on the side of the dryer.
Leave the leg run continuously. Switch the equipment that feeds the leg on and off as the dryer calls for grain. Use terminals C1 & C2, found in the high voltage cabinet, as dry contacts for this command.
- Systematically disconnect wires connected to the board to isolate the source of the short, except for the 120 volt source and neutral. Begin by disconnecting the leads connected to the Hot and Cool terminals. If the indicator lights are shorting out, it will cause the fuse that protects the board to blow. If all wires are disconnected and the fuse still blows, replace the board.
I suspect I have trouble with signal cable connections (Yellow, gray, or black cables used on exterior of dryer), causing interruptions of signals.
- Spray electrical contact cleaner on both the male and female parts of the connection to make sure both contacts are clean and free of moisture.
- Make sure connections are tightened snugly.
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