“LO” indicates that the reported temperature was 20-50/C below the System Operating Range. “HI” indicates that the reported temperature was 20-50/C

above the System Operating Range. The number following the p is the number of the probe that reported the excessive temperature.

In the event that the control temperature reported by the active control probe is more than 50/C beyond the System Operating Range, the controller will presume that the operation of the probe has been compromised by an open or shorted circuit. The controller will turn off all heating and cooling and stop controlling. Blowers will be left in the condition determined by setup parameter F15 (Blower shut-off mode). The controller display will show

p1 err

p1 -err

The minus sign in the display indicates that the reported temperature was below the System Operating Range and the absence of the minus sign indicates that it was above the System Operating Range.

Note that because the C4 will report a hi or lo condition and stop controlling for an error of 20-50/C, the only events that will typically trigger an err or - err condition is a instantaneous failure of the sensing circuit, most likely an open circuit (err) or short (-err).

3.6.1 Effect of Probe Correction on Out of Range Shutdown

Any adjustments to the probe readings made by the Software Probe Correction feature (See Section 3.8) will not affect system over/under temperature shutdown operations. The raw (uncorrected) probe readings for the current active control probe(s) are used for the system health monitoring.

3.6.2 Probe Out of Range Shutdown Reported in Error/Status String

Any Probe Out of Range Shutdown will set a bit in Byte 03 of the Error/Status String. See Section 7.8.3 for specific bit assignments.

3.6.3 Clearing a Probe Out of Range Shutdown

C4 Manual Rev 7.5.2

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Sigma C4 manual P1 err P1 -err