Technical Specification NOTES
Note 1 Purge air pressure is the minimum differential pressure required between the purge air supply pressure at “Y”
(scanner connection) and the back pressure.
Note 2 24 VDC Power supply to iScan3 must not include any inductive load.
Note 3 To achieve higher relay contact voltages, use iScan3 relay contacts to energize the coil of an interstitial relay.
Note 4 Output for monitoring only. Not to be used to prove flame.
Note 5 4-20 mA outputs are calibrated at the factory to a known load. Monitoring hardware will have an impact of the
current output. For accurate readings, 4-20 mA output(s) should be calibrated using a milli-ammeter between the
scanner’s 4-20 mA output and the monitoring hardware. Refer to the 4-20 ma Settings section MNL- iScan
Software for details on how to execute the calibration procedure.
Note 6
SUGGESTED SIL3 PROOF TESTS:
An annual proof test is good practice to meet the requirements in terms of IEC61508. According to section
7.4.3.2.2 f of IEC61508 proof tests shall be undertaken to reveal dangerous faults which may be undetected
by diagnostics test.
Flame OFF: Shutdown the burner and ensure that the flame off condition is detected and signaled by the
flame detector as a flame off condition.
False Flame: Verify that prior to start up (no flame present) there is no indication of a flame on condition
(false flame signal) on the flame scanner (this is typically integrated within the BMS as a pre-start permissive
to prevent start up if a false flame condition is detected. This should not be considered a replacement for
recommended testing of the scanner adjustments which are required to be verified each time the scanner is
commissioned, adjusted, settings are changed or re-commissioning takes place. In these cases, only qualified
personnel who have been trained and are experienced should make such adjustments.
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