Individual Unit Operation In Multiple-System While The Multi-Unit Controller (Part # 9007675005) Is Under Abnormal Conditions (Individual Operation Mode) - A.O. Smith 710 ASME Service Manual

12-11. Individual unit operation in multiple-system while multi-unit controller
(Part # 9007675005) is under abnormal conditions (Individual operation mode)
A multi-unit system of 710 models requires the multi-unit controller. If the multi-unit controller
undergoes abnormal conditions, the 710 models 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 710
models. 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 710 and the multi-unit controller.
710 models will not work individually during with a failed the multi-unit controller if the "Individual
operation mode" is disabled. See section12-5 "Individual operation mode" in Dipswitch settings of
the 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 710 installed in multiple-system.
710 / 710 ASME Service Manual
63
CONFIDENTIAL
Ver. 1.00