# Main Dryer Components

The following rendered image shows an overall view of the dryer with some of the main components highlighted. The pages following will explain these components or assemblies more in depth as well as explain the function of any associated parts.

<div align="left" data-full-width="true"><figure><img src="/files/fqfrznMHlWeneYRI8yh9" alt=""><figcaption><p>Fusion dryer is shown above as an example</p></figcaption></figure></div>

## Rotary (Bin) Fill Switch

The Rotary Fill Switch is located in the wet hopper of the tower and on the opposite end of the fill tube, or on the end of a gravity fill hopper for profile dryers.  It is powered by 24V. The switch is motorized and will rotate a paddle until wet grain comes in contact with the paddle. Once this happens, grain stops the rotation and proves the level of grain in the hopper.

## Plenum RTD

The Plenum RTD (Resistance Temperature Device) is a temperature sensing device located in the plenum used to send a signal to the PLC to establish and maintain plenum temperature. &#x20;

## Mid-Grain RTD Assembly

The two Mid-Grain RTD (Resistance Temperature Device) Assemblies are located around the perimeter of the dryer and are used to detect the temperature of the grain in the column. Each of these two RTD assemblies is equipped with a 4-20mA transmitter which provides an analog input signal sent to the PLC.

## Proximity Switch

The Proximity Switch is used to detect the rotation of the discharge metering system for profile dryers and the sweep for tower dryers, by sensing the proximity of a detector on the discharge metering shaft for profile dryers and on the shaft of the sweep motor for tower dryers.  If the rotation of the shaft goes undetected for a set duration of time, the machine will be shutdown.

## Control Power Transformer

The Control Power Transformer is used on profile dryers to transform a portion of the incoming electrical power to reliable 120V control power which is used to supply power to various electrical components including the PLC. These are only used on 575V dryers.

## Infeed DM510 Moisture Sensor (Optional)

The infeed moisture sensor is mandatory for AccuDry grain dryers, and optional for TruDry grain dryers. This sensor monitors incoming grain in real-time so that the AccuDry prediction model can react to incoming grain moisture changes. On an optional TruDry grain dryer, this will only display on the main screen, and will not affect the operation of the grain dryer


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.mathewscompany.com/dryer-operations/dryer-operations/equipment-overview/main-dryer-components.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.