Individual Unit Operation In Multiple-System While The Multi-Unit Controller (Tm-Mc01) Is Under Abnormal Conditions (Individual Operation Mode) - A.O. Smith T-M50 ASME Service Manual

12-14. Individual unit operation in multiple-system while multi-unit controller
(TM-MC01) is under abnormal conditions (Individual operation mode)
A multi-unit system of T-M50s requires the multi-unit controller. If the multi-unit controller undergoes
abnormal conditions, the T-M50s can operate as individual units. If this happens, the minimum flow
rate of the system changes from 0.5 GPM to 0.5 GPM multiplied by the number of T-M50s. Refer to the
following example:
Ex: Minimum flow rate of a five-unit multi-unit system.
Under normal conditions: 0.5GPM
When the multi-unit controller fails: 0.5×5=2.5GPM
Minimum flow rate of the multiple-system depends on the number of the units installed in the
multiple-system.
The set temperature of the units as individual units is the set temperature before the failed
communication happened between T-M50 and the multi-unit controller.
T-M50s will not work individually during with a failed the multi-unit controller if the "Individual
operation mode" is disabled. See section12-7 "Individual operation mode" in Dipswitch settings of
the central computer board
In order to make operation system effective during an abnormal condition, the number of individual
unit should be half of the total number of T-M50 installed in multiple-system.
T-M50 / T-M50 ASME Service Manual
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CONFIDENTIAL
Ver. 1.05