Sharp R-209FW Service Manual - Page 10

R-209(IN) R-209(W) R-209(Y) FUNCTION OF IMPORTANT COMPONENTS DOOR OPEN MECHANISM The door is opened by pushing the open button on the control panel, refer to the Figure D-1. When the open button is pushed, the open button pushes up the switch lever, and then the switch lever pushes up the latch head. The latch heads are moved upward and released from latch hook. Now the door will open. Latch Heads Latch Hook SW1: Monitored Latch Switch Door SW2: Monitor Switch Switch Lever SW3: Latch Switch Figure D-1. Door Open Mechanism MONITORED LATCH SWITCH SW1 AND LATCH SWITCH SW3 1. When the oven door is closed, the contacts (COM-NO) must be closed. MONITOR SWITCH SW2 1. When the oven door is closed, the contacts (COM-NC) must be opened. 2. When the oven door is opened, the contacts (COMNC) must be closed. 3. If the oven door is opened and he contacts (COM-NO) of the moniored latch switch SW1 fail to open, the fuse F1 T6.3A blows immediately after closing the contacts (COM-NC) of the monitor switch SW2. CAUTION: BEFORE REPLACING A BLOWN FUSE F1 TEST MONITORED LATCH SWITCH SW1 AND MONITOR SWITCH SW2 FOR PROPER OPERATION. (REFER TO CHAPTER "TEST PROCEDURE"). FUSE F1 T6.3A 1. The fuse F1 T6.3A blows when the contacts (COMNO) of the monitored latch switch SW1 remain closed with the oven door open and when the contacts (COMNC) of the monitor switch SW2 are closes. 2. If the wire harness or electrical components are shortcircuited, the fuse F1 T6.3A blows to prevent an electric shock or fire hazard. HIGH VOLTAGE FUSE F2 The high voltage fuse blows when the high voltage rectifier or the magnetron is shorted. TEMPERATURE FUSE TF The temperature fuse, located on the top of the oven cavity, is designed to prevent damage to the oven by fire. If the food load is overcooked, by either error in cook time or defect in the control unit, the temperature fuse will open. Under normal operation, the temperature fuse remains closed. However, when abnormally high temperatures are reached within the oven cavity, the temperature fuse will open at 248˚F(120˚C), causing the oven to shut down. TURNTABLE MOTOR TTM The turntable motor drives the turntable roller assembly to rotate the turntable. FAN MOTOR FM The fan motor drives a blade which draws external cool air. This cool air is directed through the air vents surrounding the magnetron and cools the magnetron. This air is channelled through the oven cavity to remove steam and vapours given off from heating food. It is then exhausted through the exhausting air vents at the rear of the oven cavity. TIMER MOTOR TM Timer switch 1. When the timer switch is at " " position, the switch of the timer is opened. 2. When the timer is turned clockwise from " " position, the switch of the timer is closed. NOISE FILTER The noise filter assembly prevents radio frequency interference that might flow back in the power circuit. 8