Welcome to my column where I will share best practices for Flexo Wash technology and common flexo challenges. I want to answer your real world questions, so be sure to send them to me at: service@flexowashus.com and we will feature them in an upcoming column. As your partner, I look forward to handling all your issues as soon as possible and offer lessons learned.

My Flexo Wash Narrow Web Unit Won’t Start 

Press Start... Nothing Happens? Here’s What to Do 

Have you ever gone out to your narrow web Flexo Wash unit, pressed the start button and then you see manual rotation pop up on the screen?  How about pressing start and nothing happens?  We get the call every once in a while, where this is the case. Let’s go over what may be the cause of your unit not starting. 

First, select your narrow web anilox unit

• Units Made Before 2008 (pre-circuit board units)
• Units Made After 2008 – Late 2019 (including 2019 to current NXT units)

Units Made Before 2008 (Pre-circuit board units) 

First off, on pre-circuit board units (before 2008) there are four inputs that must be present on a narrow web roll/sleeve cleaning unit for the actual wash cycle to start.

The four inputs are:

• Lid Sensor Input
• Home Sensor Input
• Start Button Input
• Emergency Stop Input

While these inputs are pretty much self-explanatory, let’s look at these in a little more detail.

Lid Sensor Input 

On pre circuit board units, if your lid sensor is not sending that 24V DC signal to input # 4 on the microcontroller, then nothing will happen on the unit.  The lid lock will not engage, the 3-way valve will not switch to drain to tank, and the diaphragm pump will not come on.  

How to Test the Lid Sensor 

To test whether your lid sensor is sending the necessary signal, you can close the lid, and you will see the inputs and outputs on the microcontroller screen. The icon for input # 4 must be illuminated. This indicates that you are getting the correct signal from the lid sensor. 

All Inputs Are Lit… But Still No Action? 

In this case, it would be input #s 

• 1 (wash time 5 minutes) 
• 3 (start input) 
• 4 (lid closed) 
• 5 (emergency stop) 
• and 6 (home sensor) 

Please note that depending on what length of wash cycle you have selected (on the switch located on the front of the unit), you may not have an input on #1. If wash time 2 is selected, there will be no input. If wash time 3 is selected, input # 2 will be illuminated.) 

If all the correct inputs are illuminated, When the wash cycle starts, you will see a timer on the screen start to count down. If all the inputs are present and you see the counter on the screen, but your diaphragm pump doesn’t come on, then we have another issue. The microcontroller may be dropping an output or one of the solenoid valves on the valve block may be bad. 

Before you call the shop, make sure that all of the inputs listed above are present and we can take it from there. If you are missing an input, then you will need to check the corresponding component for a 24V DC signal (start button, lid sensor, emergency stop and home sensor). 

Units Made After 2008 – Late 2019  

(Including 2019 to current NXT Units) 

These newer units still require the same inputs, but there are a few additional things to watch out for.  Please read the section on inputs above, and then continue on if your anilox cleaner still won't start.

For units made after 2008 to late 2019 that have a circuit board and the LED display, the inputs required are the same. This also includes NXT units made from late 2019 to current. 

Low Liquid Level & Float Sensor 

You still need the lid sensor, home sensor, start button and emergency stop inputs.  However, you will also need to make sure that the liquid level sensor has not tripped. This can be seen on the screen as a “low liquid level” alarm. On NXT units, you will have a low-liquid alarm on the alarm page. The liquid-level indicator on the NXT screen will also be red. So, if the low-level input is made, the unit won’t start.  You need to check and make sure that the liquid level in the tank is correct.  If there is enough cleaning solution in the tank, then the float sensor may be bad. 

Low Temperature Alarm 

All circuit board units also have a “low temperature” alarm. 

On the 2008-2019 units:

• This alarm will be displayed on the screen.

On the newer NXT units:

•  This alarm will be present on the alarm page.
  

The unit will not start if the cleaning temperature does not meet the lower set point that has been established in the settings/recipe.  

Seeing “Manual Rotation” on the Screen? 

On circuit board units, if the lid sensor is not sending a signal when the lid is closed, when start is pressed you will see “manual rotation” pop up on the LED screen and manual rotation will start on the unit. 

This is a very good indication that the lid sensor is not functioning.  

If you check that lid sensor and you are getting a 24V DC signal to the start input on the circuit board and “manual rotation” still comes up, then another one of the inputs may not be present. 

As with the microcontroller units, if you are dropping any of the inputs, the unit will not start. You can check the wiring diagram for your unit to make sure that the correct inputs are present on the circuit board. 

It is also possible that the start button may be bad.  There is a consistent 24VDC going through the start button. When the start button is pressed, the DC voltage drops to the board briefly, which allows the unit to start. If you check the start button inputs and the voltage does not drop when the start button is pressed, then the start button is bad. 

It is important to note, that on circuit board units, if all the inputs are present, start is pressed and the wash time comes up on the LED screen but the diaphragm pump does not come on and the 3-way valve does not switch to drain to dank, then one of the solenoid valves on the valve block may be bad or the circuit board may be dropping an output. 

Still Not Working? 

If you’ve checked all the above and your unit still refuses to cooperate, don’t waste more time scratching your head, give us a call at the shop and we’ll dig into it with you. It’s usually something simple. And if it’s not, well… we’ve seen it all. 

Every Minute Counts. Don’t Waste It on Downtime. 

The Downtime Eliminator & Customer Service Manager 

As always, if you need immediate assistance, call us at Toll Free: 888-493-5396 | F: 888-543-5396

2010 Plantside Drive
Louisville, KY 40299
1-888-493-5396