Coefficient table is full when adding a MR-VAV to an SLI controller.

Issue

Coefficient table is full when adding a MR-VAV to an SLI controller.

Product Line

TAC I/NET

Environment

I/NET Site with MR-VAV

Cause

Coefficient table is full when adding a MR-VAV 

Resolution

An MR-VAV needs 7 Conversion Coefficients in order to complete the update MCI, but it can re-use coefficients which already exist in the table,e.g.0.018 and -148 for thermistors. If your table is full, see if you have duplicates of values in your Coefficient table. If you do re-direct, the points that have the same values. For example if 4 and 15 are the same values then select coefficient 4 for all of the points using coefficient 15 and change 15 to 0 and 0. That will open up one coefficient at line 15.

See if their are more to open up. If not and you have close values, you might merge the values that are close together. Check to see how much it changes your actual output value. If it isn't much then that will probably work fine. I change some of my cfm Coefficient tables to make an 8 in. duct to match a 10 in. duct and the actual cfm did not change enough to worry about.

If the value is close but not close enough, try adjusting the hardware coefficients for those points to fine tune them.

If you then get an error indicating that your engineering table is full, open that one up to do the same as above. Point cfm's, percentage's, etc. to one cfm and one percentage.