137
JOHNSON CONTROLS
5276178-JIM-C-0118
5
STAGING
DOWN
NEXT STAGE TO DISABLE
STAGE 4 TO 3
COMPRESSOR 3 READY TO STOP AND COMPRESSOR 4 READY TO STOP, THE UNIT CONTROL
WILL SET NEXT STAGE TO DISABLE TO EITHER 3 OR 4, WHICH EVER COMPRESSOR HAS THE
FEWEST NUMBER OF STARTS.
STAGE 3 TO 2
THE UNIT CONTROL WILL SET NEXT STAGE TO DISABLE TO EITHER 1 OR 2, WHICHEVER HAS THE
FEWEST NUMBER OF STARTS.
STAGE 2 TO 1
THE UNIT CONTROL WILL SET NEXT STAGE TO DISABLE TO THE REMAINING COMPRESSOR
FROM THE STAGE 4 TO 3 TRANSITION.
STAGE 1 TO 0
THE UNIT CONTROL WILL SET NEXT STAGE TO DISABLE TO THE COMPRESSOR REMAINING
FROM THE STAGE 3 TO 2 TRANSITION.
STAGING UP
NEXT STAGE TO ENABLE
STAGE 0 TO 1
IF COMPRESSOR 1 READY TO RUN AND COMPRESSOR 2 READY TO RUN ARE BOTH TRUE,
THE UNIT CONTROL WILL SET NEXT STAGE TO ENABLE TO EITHER 1 OR 2, WHICH EVER
COMPRESSOR HAS THE SMALLEST NUMBER OF STARTS.
STAGE 1 TO 2
IF COMPRESSOR 3 READY TO RUN, COMPRESSOR 4 READY TO RUN ARE ALL TRUE, THE UNIT
CONTROL WILL SET NEXT STAGE TO ENABLE TO EITHER 3, OR 4, WHICH EVER COMPRESSOR
HAS THE SMALLEST NUMBER OF STARTS.
STAGE 2 TO 3
THE UNIT CONTROL WILL SET NEXT STAGE TO ENABLE TO THE COMPRESSOR REMAINING
FROM THE STAGE 0 TO 1 TRANSITION.
STAGE 3 TO 4
THE UNIT CONTROL WILL SET NEXT STAGE TO ENABLE TO THE COMPRESSOR REMAINING
FROM THE STAGE 1 TO 2 TRANSITION.
TABLE 71
-
COMPRESSOR STAGING
The Unit Controller then varies the 0 to10V analog
output to the VFD to maintain the
“DUCT STATIC
PRESS ACTIVE SP”.
COMPRESSOR STAGING SEQUENCE
Compressors are staged up or down to control the
“SUPPLY AIR TEMP CURRENT”
to the
“SUPPLY
AIR TEMP ACTIVE SP”.
The compressor staging sequence is determined by
the unit size. This parameter is set through the User
Interface as follows:
•
“UNIT SIZE” –
OPTIONS key / UNIT DATA
subsection.
Содержание 40 25 TON
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