beautypg.com

American Dryer Corp. ADS-464 II User Manual

Page 75

background image

71

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