American Dryer Corp MLG-460 manual Sprinkler Circuit Description

•L4 (light #4) is an “amber” light associated with PB #10 (push button #10), the “SPRINKLER RESET” button. These items are located on the electrical enclosure’s front panel. L4’s function is to give a visual indication that the sprinkler function is asserted and that the pneumatically activated water valve is open.

•The air actuated water valve also has a visual indicator to show its current state. Notice a “RED” button on the rear side of the valve.

•IN = Valve CLOSED

•OUT = Valve OPEN

NOTE: The sprinkler water inlet line has a hand operated gate valve and must be open for water to flow. It is suggested that this manual valve be closed when working on the dryer, to avoid problems caused by false tripping of the sprinkler circuit.

IMPORTANT: BE SURE TO TURN ON THE VALVE WHEN THE WORK IS COMPLETE.

•PB #10 (push button #10) “SPRINKLER RESET” button is for resetting the sprinkler circuit once the temperature in the tumbler (basket) has dropped below its preset trip temperature.

NOTE: Pressing the “SPRINKLER RESET” button before the tumbler (basket) temperature has dropped below its trip temperature will momentarily stop the water flow. However, the water flow will resume once the button is released.

•UV is the “UNDER VOLTAGE” detection coil of the dryer MAIN DISCONNECT switch, DISC #1. It is this device that controls the automatic POWER DOWN of the dryer when the sprinkler is activated.

SPRINKLER CIRCUIT DESCRIPTION

The following information assumes that the reader has read the sprinkler component descriptions and is following the MLG-460 Ladder Diagram of the Sprinkler Circuit.

•STATE 1 - The tumbler (basket) temperature is “BELOW” SHLC (Sprinkler High Limit Controller) preset trip value. When power is applied to SHLC:

•SHLC set point will close.

•SHLC alarm will open.

•UV (under voltage) will engage.

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