Boiler house Level controls
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Weekly test High integrity self-monitoring level controls do not require daily testing but the weekly test should be carried out or witnessed by a responsible person who appreciates the hazards involved and has been suitably trained in the safe operation of the boiler and its controls. At no time during the test should the water be lowered to the extent that it disappears from the gauge glass. 1. With the feedpump switched off, or the control valve forced closed, allow the water level to fall by evaporation until the burner and the panel lockout at the low alarms. 2. Raise the water level to normal, reset the lockout and allow the burner to refire. 3. To independantly test inputs of a 2 probe system external test buttons have to be installed that create low level alarms on each probe input. For each probe input press the test button and ensure the burner shuts down, afterwards reset the lockout and allow burner to refire. 4. Include in monthly test - Under hand control raise the water level to the high alarm level. Check that the high alarm sounds. 5. Return all valves and controls to normal and monitor the boiler until satisfied that it is operating normally. Quarterly inspection The Health and Safety Executive recommend from experience that the boiler controls should be serviced at least at quarterly intervals. Where the regular tests are carried out properly in a well run boiler house with good water treatment, it may be that only an annual inspection of the probes etc. is required. This is a matter, however, for the user to decide in liaison with his insurance company inspector in order to determine a sensible inspection programme to suit the individual boiler plant. We recommend a regular inspection as follows: 1. Inspect the probe plugs for moisture. 2. Unscrew the probes and wipe away any dirt from the probe tips. If any hard scale is present it may be an indication of more serious scale formation elsewhere in the boiler. Investigate water treatment.
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3. Inspect the wiring and controllers for damage. 4 . Reassemble and carry out a full functional check.
AI-P693-32 EMM Issue 1
LCSR5000 Level Control Systems
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