Issue

A Matrix UPS will not allow the user initiate a runtime calibration.


Product Line

Matrix UPS



Environment

All serial ranges


Cause

There are several requirements that must be met before a user can initiate a runtime calibration on a Matrix UPS.


Resolution

A run time calibration is only required when old batteries are replaced or if the estimated run time is found to be significantly inaccurate. Older batteries (i.e. more than two years apart) should not be mixed with new ones.

It is unnecessary to subject a battery bank to an excessively long calibration. Remove battery packs or increase the load (space heaters are good dummy loads) to obtain a reasonable time length for the calibration (under an hour if possible). At the start of a calibration, the Matrix microprocessor saves the Estimated Run Time displayed.  The unit will then go to battery power until the capacity is 25%. After this run time has been completed, the original Estimated Run Time is compared with the actual run time. It will then increase or decrease this value to correspond to the new run time achieved. If, at any time during the discharge, one of the following rules is violated the calibration will be aborted or corrupted:

1. Battery capacity must be 100% at start of calibration (all packs must indicated as float).

2. Initial "Estimated Run Time" must not exceed 128 minutes (remove battery packs if necessary).

3. Load must be above 25%.

4. Load must not fluctuate more than ± 5%.

5. The UPS must be allowed to run down to 25% battery capacity. PowerChute and Accessories must be removed since they can abort the calibration prematurely.

Published for:APC Belgium