American Dryer Corp. ADS-464 II User Manual
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1. TEMPERATURE SENSING COMPONENT DESCRIPTIONS
Exhaust RTD (Resistive Temperature Device) - Sens1
The RTD (Resistive Temperature Device), used throughout the ADS-464 are identical. The main function
is to measure temperatures and to transfer this information to a measuring device for further processing.
The RTD used on the ADS-464 are rated for 1100° F (593.3° C).
Sens2 = Exhaust Temperature Sensor
The exhaust RTD (Resistive Temperature Device) is located in the ADS-464 burner area exhaust duct
and also has electrical disconnects in a junction box for ease of replacement.
Exhaust 4 to 20 milliampere (4 to 20 mA) transmitter - Trans1
This transmitter is located on the upper right of the main electrical enclosure panel. The intake and
exhaust RTD (Resistive Temperature Device) are respectively connected in series with a 24 volt DC
power supply, and the current drawn from the power supply is 4 to 20 milliampere (4 to 20 mA) output
signal which is proportional to the input signal. The proportional current information is the connected to
the PLC (Programmable Logic Controller) for processing. Refer to the ADS-464 Ladder Diagram for
circuit information.
24 Volt DC Power Supply
The 24 volt power supply used in the ADS-464 is an individual grade switching power supply, rated for
120 volts AC input and 24 volts DC output. The features that this device incorporates are:
Overload protection to protect the LOAD
Internal failure protection to protect itself
An output status indicator; this L.E.D. (light emitting diode) indicates the presence of DC output voltage.
PLC (Programmable Logic Controller) Analog Input Module - Module #2
This device, attached to the PLC, receives the 4 to 20 milliampere (4 to 20 mA) temperature information
and processes this information for the PLC
Temperature Measurement and Sensing Problems
An EXHAUST DSFL MESSAGE is displayed on the operator terminal any time a respective
temperature measurement has exceeded the programmed temperature in the PLC (Programmable Logic
Controller). A DSFL message will stop the current drying cycle and prevent a drying cycle from
starting.
2. EXHAUST DSFL MESSAGE
a. PROBABLE CAUSES;
1) Defective RTD (Resistive Temperature Device) Probe
2) Defective 24 Volt DC Power Supply