Carrier 30GN040-420 operating instructions mA Demand Limiting

Fig. 9 Ð 4-20 mA Demand Limiting

Factory Con®guration Codes Ð allows entry into

the factory con®guration subfunction. Under this subfunc- tion, there are 7 groups of con®guration codes that are down- loaded at the factory. Each group is made up of 8 digits. If processor module is replaced in the ®eld, these 7 groups of con®guration codes must be entered through the keypad and display module. Factory con®guration codes (groups 1 through 7) that apply to the particular Flotronic™ II chiller being serviced are found on a label diagram located inside the control box cover. See Table 13 for a summary of factory con®guration subfunction keystrokes.

Adjustable Field Con®gurations Ð After logging on, press

to enter subfunction. The subfunction allows opera- tion of the chiller to be customized to meet the particular needs of the application. The chiller comes from the factory precon®gured to meet the needs of most applications. Each item should be checked to determine which con®guration alternative best meets the needs of a particular application. See Table 14 for factory loaded con®guration codes and al- ternative con®gurations.

If processor module is replaced, the replacement module is preloaded with factory default con®guration codes. Each con®guration code must be checked and, if necessary, re- con®gured to meet needs of the application. See Table 14 for pre-loaded service replacement con®guration codes.

Service Con®guration Codes Ð Press to enter the

service con®guration subfunction. The ®rst 2 items under this subfunction are 2 groups (8 digits each) of con®guration codes that are downloaded at the factory. If processor module is

replaced in the ®eld, the 2 groups of con®guration codes must be entered through the keypad and display module. The 2 groups of con®guration codes (groups 8 and 9) that apply to the unit being serviced can be found on a label diagram inside the control box cover. See Table 13 for keystroke in- formation to enter con®guration codes 8 and 9. The remain- ing items in this subfunction are read-only data provided to assist in service evaluations.

SCHEDULE FUNCTION Ð This function provides a means to automatically switch chiller from an occupied mode to an unoccupied mode. When using schedule function, chilled fluid pump relay must be used to switch chilled ¯uid pump on and off. Connections for chilled ¯uid pump relay are: TB3-3 and TB3-4. The chilled ¯uid pump relay starts chilled ¯uid pump but compressors do not run until remote chilled ¯uid pump interlock contacts are between TB6-1 and TB6-2 are closed and leaving chilled ¯uid temperature is above set point. If a remote chilled ¯uid pump interlock is not used, the ®rst compressor starts (upon a call for cooling) approximately one minute after chilled ¯uid pump is turned on.

The unit can be programmed for inactive, single set point, or dual set point operation.

When unit is con®gured for inactive, chilled ¯uid pump relay remains energized continuously but is not used since chiller is usually controlled by remote chilled ¯uid pump in- terlock contacts.

When unit is con®gured for single set point operation, chilled ¯uid pump relay is energized whenever chiller is in occu- pied mode regardless of whether chiller is running. When chiller is in unoccupied mode, chilled ¯uid pump relay is not energized.

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