LAARS SC 12 - Install and Operating Manual - Manual (Page 27)

Page 27 Laars Sequencing Controls
There are more than one green lead stage lights on
Check the 120VAC power input to the SC. Turn power to the SC off and back on. If only one lead stage LED does not light, the
unit may be damaged.
Lead Stage does not rotate when switch to INCREMENT
Only units which have (all stages of) their OFF/AUTO/ON switches in the OFF/AUTO/ON OFF/AUTO/ON AUTO position and which are designated as Unit or
Lo stages (see chart on pg. 19) can be lead. If there is more than one stage which meets this criteria, the SC may be damaged.
Lead Stage does not rotate every 24 hours (First On/Last Off Rotation)
Check the dip switch is set up for First On/Last Off rotation (see pg. 4). Check the lead stage can be rotated as described above.
Finally, check if the INCREMENT/OFF/AUTO switch is in the AUTO position. In the AUTO position, the lead stage should
rotate among the possible lead stages every 12 hours after the unit is fi rst powered up, and then every 24 hours thereafter. If the
panel loses power, the lead stage and the rotation counters will be reset.
Lead Stage does not rotate First On/First Off
Check the dip switch is set up for First On/First Off rotation (see pg. 4). Check the lead stage can be rotated as described above.
Finally check if the INCREMENT/OFF/AUTO switch is in the AUTO position.
STAGE OUTPUTS
When switched to ON, the unit does not come on
Remove any wires attached to the SC output. Check for continuity across the SC N.O. contacts. If there is continuity, the SC
output is working correctly. Check the wiring and the unit being energized to determine why it is not operating.
Red stage light is lit, but the unit is not on
The SC is calling for this unit to be on. Follow the procedure above.
Red stage light is not lit, but the unit is on
SC N.O. contacts. If there is no continuity, the SC output is working correctly. Check the unit for any other operating controls
which may be causing it to run.
Stage Outputs don’t Sequence
Make sure that the red output lights on the SC correspond to the stage’s operation. If they don’t, follow the steps above.
temperature is correct and the display does not read OFF or PrF. Finally, check the OFF/AUTO/ON stage switches. Only OFF/AUTO/ON OFF/AUTO/ON
units which (have all stages) switched to AUTO will be part of the automatic Sequencing.
SYSTEM OUTPUT
When switched to ON, the SYSTEM component does not come on SYSTEM SYSTEM
Remove any wires attached to the SC SYSTEM terminals. Check for continuity across the N.O. contacts. Then check the
N.C. terminals are open. If both are true, the SC is working correctly. Check the wiring and the component being energized to
determine why it is not operating.
Red stage light is lit, but the SYSTEM component is not on SYSTEM SYSTEM
The SC is calling for the unit. Follow the procedure above.
Red stage light is not lit, but the SYSTEM component is on SYSTEM SYSTEM
The SC is not calling for the unit to run. Remove any wires attached to the SC SYSTEM output terminals. Check the N.O. SYSTEM SYSTEM
terminals are open. Then check the N.C. terminals are closed. If both conditions are true, the SC output is working correctly.
Check the unit for any other operating controls which may be causing it to energize.