224 Exam Chair Drawer Heater Test and Repair

Problem Required Action
Heater does not warm up. Test fuses at chair bases. Refer to: Fuses and Connections
Test drawer heater switch. Refer to: Drawer Heater Switch
Test drawer heater plate. Refer to: Drawer Heater Plate
Check output voltage from isolation transformer. Refer to: Isolation Transformer

224 Exam Chair Drawer Heater Test and Repair

This illustration shows only the fuses and connections that affect the Drawer Heater.

224 Exam Chair Drawer Heater Test and Repair

Caution

Unplug power cord before removing receptacle cover.

1.Remove receptacle cover.

2.Remove two screws and place receptacle aside.

3.Disconnect the white wires from heater switch to the heater plate.

4.Plug in power cord.

5.Set meter to VAC.

6.Depress switch On.

7.Place meter probes on two white wires from drawer heater switch.

Meter Reading Required Action
0 VAC Replace switch.
Approx. 115 VAC Switch OK. Refer to: Drawer Heater Plate
Caution

Unplug power cord before reconnecting electrical leads.

8.Reconnect electrical leads.

224 Exam Chair Drawer Heater Test and Repair

Caution

Unplug power cord before removing receptacle cover.

1.Remove receptacle cover.

2.Remove two screws and place receptacle aside.

3.Disconnect the white wires from heater switch to the heater plate.

4.Set meter to Ω.

5.Place meter probes on the two white wires from heater plate.

Meter Reading Required Action
0 Ohms Replace Heater Plate.
538 Ohms +/- 10% Heater Plate OK.
Caution

Unplug power cord before reconnecting electrical leads.

6.Reconnect electrical leads.

224 Exam Chair Drawer Heater Test and Repair

Caution

Unplug power cord before removing receptacle cover.

1.Remove receptacle cover.

2.Remove two screws and place receptacle aside.

3.Disconnect the black and red wires from isolation transformer to heater switch.

4.Plug in power cord.

5.Set meter to VAC.

6.Place meter probes on the black and red wires from isolation transformer.

Meter Reading Required Action
0 VAC Replace transformer.
Approx. 115 VAC Transformer OK. Refer to: Drawer Heater Switch
Caution

Unplug power cord before reconnecting electrical leads.

7.Reconnect electrical leads.