Do you need a manual panel with your concrete batching system?

We’ve heard that question more times than we can count. Unfortunately, the answer is not black and white because different scenarios come with different requirements and more importantly, all manual panels are not equal. First, we need to understand what a concrete plant needs in order to be controlled.

Concrete plants include devices like solenoids and motor starters that enable a plant to be controlled via electricity (as opposed to pulling manual levers as was once done). Generally, the electrical devices consist of 120VAC controls in the United States or 220VAC controls in other countries. There are some exceptions where plants are controlled with 24VAC or 24VDC but the majority fall into a high voltage category.

If your plant requires high voltage (120/220) to control it, then the manual panel needs to supply it. For example, if you want to open an overhead sand bin, and your plant needs 120VAC to do this, your manual panel must ultimately provide that voltage to the sand bin solenoid to open the bin. Pretty simple right?

Types of Concrete Batching System Manual Panels

There are three types of manual panel that accompany concrete batch computers. Each type provides voltage to the plant in different ways.

  1. Virtual Manual Panel
    A virtual manual panel is basically a screen in a concrete batching system software application that includes buttons the user clicks with a mouse that act like switches to control the item on the concrete plant. Sometimes these virtual manual panels include touch screens to make it easier to push these on-screen buttons. Virtual manual panels use “relays” (usually solid state relays) that take a small low voltage signal to turn them on (provided by the batch computer) and then these relays then pass the high voltage to the plant. This means that the batch computer and entire low voltage system are required for the virtual manual panel to operate.
    • Pros
      • No additional components needed so the batching system should be much cheaper than a batch system that includes a manual panel.
      • Takes up less desk space.
    • Cons
      • Multiple points of failure can prevent you from having manual control of your plant from a batching system computer failure, a low voltage power supply failure, a circuit board failure or relay failure to name a few.
      • Difficult to quickly do things like manually add water or a forgotten admix to a load.
      • Highest susceptibility to lightning strikes of all manual panel types.
  2. Low-voltage Manual Panel
    A low-voltage manual panel is a physical manual panel separate from the concrete batch computer. It has physical switches that are connected relays that are connected to the individual parts of the plant to be controlled. Like a virtual manual panel, a low-voltage manual panel sends low voltage to a “relay” (usually sold state relay) and then these relays then pass the high voltage to the plant. This means that the entire low voltage system is required for the low-voltage manual panel to operate.
    • Pros
      • Low-voltage manual panels are often slightly smaller than high-voltage manual panels and take up less desk space.
      • You can quickly perform manual tasks without needing to use a mouse or open separate screens in software.
      • Low-voltage manual panels are cheaper to build than high-voltage manual panels and therefore should be cheaper than concrete batching systems that include high-voltage manual panels.
    • Cons
      • Multiple points of failure can prevent you from having manual control of your plant from a low voltage power supply failure, a circuit board failure or relay failure to name a few.
      • False sense of security since the user has a physical panel. It might be assumed by the user that the low-voltage panel will always be able to provide manual backup.
      • Moderate susceptibility to lightning strikes.
  3. High-voltage Manual Panel
    A high-voltage manual panel is a physical manual panel separate from the concrete batch computer. It has physical switches that are connected to the individual parts of the plant to be controlled. Unlike low-voltage and virtual manual panels, no additional components stand between the manual panel switch and the plant device being controlled. The switch physically passes the high voltage required by the plant device to the device.
    • Pros
      • No additional device failures can prevent the high-voltage manual panel from being able to control the plant because the switches connect directly to the plant via cables. Only a total power failure can cause the high-voltage panel to not function in which case nothing else on the plant would function either.
      • Almost no susceptibility to lightning strikes.
      • You can quickly perform manual tasks without needing to use a mouse or open separate screens in software.
    • Cons
      • High-voltage manual panels are sometimes larger than low-voltage manual panels and take up slightly more desk space.
Manual panel fit for purpose by type

Now that you know the concrete plant requirements and the different types of manual panels available, how do you know which is best for your situation? We’ve outlined the factors that impact your decision the most as to what type of manual panel is best for your situation.

  1. Virtual Manual Panel
    • You pour concrete exclusively for customers that require batch weight printouts. This means a batch computer failure is equal to a plant failure and having a manual panel is of little use. Keep in mind, this means you could not even prevent a cold-joint.
    • You have another plant close enough in proximity and with enough capacity to divert orders to in the event you have a batch computer failure.
    • You have a low risk of lightning strikes in your area.
    • You perform limited manual adjustments for any reason and having a convenient physical manual panel is of limited value.
  2. Low-voltage Manual Panel
    • You pour concrete exclusively for customers that require batch weight printouts. This means a batch computer failure is equal to a plant failure and having a manual panel is of little use. Keep in mind, this means you could not even prevent a cold-joint.
    • You have another plant close enough in proximity and with enough capacity to divert orders to in the event you have a batch computer failure.
    • You have limited risk of lightning strikes in your area.
  3. High-voltage Manual Panel
    • You pour a reasonable percentage of concrete for customers that do not require batch weights and could continue to batch manually if your batch computer failed.
    • You have no other plants in close proximity or with enough capacity to divert orders to in the event of a batching system failure.
    • You have a moderate to high risk of lightning strikes in your area.
Conclusion

We hope the information above helps you understand the differences in types of manual panels related to concrete batching systems. Additionally, Zylocon batching systems use high-voltage manual panels. Although some situations might exist where a high-voltage manual panel could be considered more than is absolutely required, there is no situation where a high-voltage manual panel is a negative. Many circumstances come into play when deciding what is best for any one situation and we are always here to answer any questions you may have.

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