Emerson Process Management MSL600 Stop If P252, Start Time P253, Interval P254, Max Retries P257

Installation, Operation & Maintenance Manual

IP262/Z0, Rev. AB

February 2012 MSL600

7.3.3Stop If - P252

Use this parameter to select if it is necessary to override the “Stop on” condition. The selectable options are:

￿Not used

￿Sludge Level

The parameter defaults to none which means it is not used.

Parameter values:

Default	Min	Max
None	-	-

7.3.4Start Time - P253

This is the time of the day at which the first de-sludge operation starts. The time is programmed in hours and minutes. This parameter is set up in conjunction with the de-sludge Interval P254.

Parameter values:

Default	Min	Max
07:00	-	-

7.3.5Interval - P254

The parameter is the interval between de-sludge events.

After a start time has been programmed, the interval between each de-sludge needs to be programmed.

For example, if it is required that the de-sludge cycle starts at 7:00am each morning then 07:00 is entered in P253. If it is then required that a de-sludge cycle is carried out every hour thereafter, 01:00 is entered in P254.

Parameter values:

Default	Min	Max
01:00	-	-

7.3.6Max Retries - P257

This parameter is the maximum number of retries allowed following an unsuccessful de-sludge cycle. If the maximum retries is exceeded, and a relay is programmed, and allocated in alarm mode, it can be used to signal this fact.

A retry occurs if the start condition is still present when the stop condition occurs or if a relay maximum run time is exceeded and the stop condition has not been reached.

To prevent a relay from remaining on, the relay minimum off time must be programmed (see P415).

Parameter values:

Default	Min	Max
10	0	250

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