State Industries SBD85 500 - Manual (Page 31)

SBD TANK TYPE HEATERS
SERVICE HANDBOOK
Technical Training Department
Ashland City, TN ©2003
30
TROUBLESHOOTING THE EFFIKAL DAMPER (continued)
Condition:
Thermostat closed, damper is open fully
STEP 10A TEST FOR 24VAC BETWEEN BLACK AND YELLOW
IF THEN
24VAC is present
This is correct – continue to Step 11
24VAC is not present
•
See Step 9B.
•
Check the harness plug connecting.
•
Check that cam on shaft rotates with
shaft.
•
Replace the damper board.
•
Ensure that cam is secure against end
switch.
Condition:
Damper rotates continuously
STEP 10B ADJUST END SWITCH TO CAM CONTACT
IF THEN
Damper stops in proper position
24 VAC should be open on a call for heat
and close during standby/
Damper does not stop in proper position
•
Replace damper assembly.