Test Procedures - Sensors
All electrical components in this ice machine can be diagnosed with a volt-ohmmeter.
Curtain Switch:
1. Test using the controller’s indicator lights. Observe
SW1
and
SW2
and the
Period
in the display
code. Open and close the curtain in question. When the curtain is opened, the SW light will be ON.
When the curtain gets to within a half inch of closing (at the switch) the SW light will go OUT.
2. Test with an ohmmeter. Disconnect electrical power. Open the control box cover. Unplug the curtain
switch lead from the controller. Connect an ohmmeter to the leads of the switch. Open and close the
curtain. When the curtain is closed, the switch is closed and there will be continuity - a good curtain
switch will have very low resistance when the curtain is closed - .5 to 2 ohms. A defective switch has
about 100 or more ohms of resistance when the curtain is closed. When the curtain is open, the switch is
open and the circuit will be open.
3. Test the controller’s curtain switch circuit by jumping the connectors on J1 or J2 together. Reconnect
electrical power. When jumped, the matching SW light will go out. When unplugged or open, the SW
light will be ON.
November 2010
Page 23
C2648 Service Manual
Curtain Switch Indicator Lights
Light is ON when curtain is OPEN
Curtain
Switch
Period is Curtain Switch 3 Indicator
Light