American Dryer Corp. MLG-460 User Manual

Page 75

b) POSSIBLE SOLUTIONS;

1b) For Air Flow problems refer to SECTION III - Item D (External Supply Connections) -

paragraph #4 (Exhaust Air Ducting) on page 20 and page 21.

NOTE: An illuminated “RED” L.E.D. (light emitting diode) indicator on the HI-TEMP CONTROLLER

indicates that the Hi-Limit control relays is in “ALARM” and an internal relays is “OPEN”.

• If anyone of the HI-LIMIT Temperature SENSORS sense an over temperature condition. It will

open its control relay. (Refer to the dryer Ladder Diagram for the effect of this relay).

• If a “HI-TEMP FAULT” message is displayed, open the main electrical enclosure, and notice

which channel has cycled. This will lead one in the direction of the fault.

HLS1 = MAXIMUM INTAKE TEMPERATURE

HLS2 = MAXIMUM OVER BURNER TEMPERATURE

HLS3 = MAXIMUM EXHAUST TEMPERATURE

• The HI-TEMP controller channel that has a “GREEN”

L.E.D. (light emitting diode)

“ON,”

indicates the RTD (Resistive Temperature Device) that caused the message (HI-TEMP FAULT)
to be displayed.

• Let the dryer cool and verify that “GREEN” L.E.D.’s resume scanning. Reset the controller by

pressing the “REST” on the controller. This will verify that an over temperature condition occurred
and the controller is operational.

• Go to paragraph #1b above and check air flow.

• If the HI-LIMIT controller does not reset go to paragraph #3b on page 72.

2b) If either RTD (Resistive Temperature Device) 1, 2, 3 were to open or become disconnected, the

associated temperature channel, of the hi-temp controller located on the Main Electrical Panel, will
sense the open and react by opening its respective control relay and never reenergize until the RTD
was replaced. Once a HI-LIMIT controller problem has been isolated to a particular device, and a
RTD temperature sensor is suspected:

Check the resistance of the RTD (Resistive Temperature Device) at its connector, located in the
right hand cable through.

• If 0 ohms (0

Ω

) is measured;

• Check RTD (Resistive Temperature Device)

• Check wiring to the RTD (refer to the main panel wiring diagram)

• Check wiring to the HI-LIMIT temperature controller (refer to the dryer Main Panel Wiring

Diagram).