140
JOHNSON CONTROLS
5276178-JIM-C-0118
Sequence of Operation
NonFlexSys Economizer
Once the
“ECONO SYS STATUS”
is
“NORMAL
- ACTIVE”
the Unit Controller will use the
“ECONOMIZER
CONTROL OUTPUT”
to control the
return and outdoor damper to maintain the
“SUPPLY
AIR TEMP ACTIVE SP”.
FlexSys Economizer
The FlexSys economizer suitability is the same as
the above except for the
“OUTSIDE AIR TEMP”
requirement. On FlexSys units the
“OUTSIDE AIR
TEMP”
must be at least 2°F below the
“MX SUPPLY
AIR TEMP SETPOINT”
in order for the economizer to
become NORMAL - ACTIVE.
When the economizer is
“NORMAL - ACTIVE”
it will
go “NORMAL INACTIVE” if the
“OUTSIDE AIR
TEMP”
is equal to or above the
“MX SUPPLY AIR
TEMP SETPOINT”
.
Also when economizer is active, the Set Point for the
“ECONOMIZER CONTROL OUTPUT”
will be the
“MX SUPPLY AIR TEMP SETPOINT”
setting and
the Feedback will be the
“MX SUPPLY AIR TEMP
CURRENT”.
COMPRESSOR OPERATION
Compressor Data
In order to assist the Service Technician and to assure
equal wear on all the compressors in the unit the Unit
Controller records the following data pertinent to
compressor operation for each compressor:
Compressor Starts
– Each time one of the compressors
state transitions from OFF to ON the
“COMPRESSOR
# STARTS”
will be incremented by one, where # will
vary to match the compressor number the data is being
recorded for, 1A (1), 1B (2), 2A (3) etc. This data can
be view under the OPERATING HOURS / START
COUNTER key of the User Interface.
Compressor Operating Hours
– While the compressor
is in the ON state the
“COMPRESSOR # OPER HRS”
will be incremented once for every hour of operation.
This value will be accumulated over the lifetime of the
compressor. The number symbol will vary to match
the compressor number the data is being recorded for,
1A (1), 1B (2), 2A (3) etc. This data can be view under
the OPERATING HOURS / START COUNTER key
of the User Interface.
Compressor Run Time
– while the compressor is in
the ON state the
“COMPRESSOR # RUN TIME”
shall
be incremented once per minute. The value will only be
accumulated during the current run state and will be reset
to zero when the COMPRESSOR RUN STATE switches
from ON to OFF. The number symbol will vary to match
the compressor number the data is being recorded for.
This data can be viewed under the COMPRESSOR
SYSTEMS key of the User Interface.
Compressor Ready to Run
In order to determine if a compressor is ready to run
the Unit Controller monitors the following derived data
while the
“COMPRESSOR # STATE”
is OFF to make
the determination:
•
“HIGH DP UNLOAD”
•
“LOW AMB INHIBIT”
•
“LOW SUCTION TEMP UNL”
•
“COMPR # SAFETY TRIP”
•
“COMPR # SAFETY FAULT”
•
“COMPR # STAFETY LOCK OUT”
If all of the above parameters are FALSE (not active) and
the minimum off time has been satisfied, the compressor
will be placed in the ready to run state.
The number symbol will vary to match the compressor
number the data is being recorded for, 1A (1), 1B (2),
2A (3) etc.
Compressor Ready to Stop
The Unit Controller will set the
“COMPRESSOR #
READY TO STOP”
to true when the MINIMUM ON
TIMER (3-1/2 minutes) has been satisfied.
The number symbol will vary to match the compressor
number the data is being recorded for, 1A (1), 1B (2),
2A (3) etc.
Compressor Safety Circuit
Each compressor system is equipped with external
circuitry monitoring hardware intended to protect the
compressors in case the operating characteristics of
the refrigeration system fall outside the safe operating
envelope for the compressors.
Summary of Contents for 40 25 TON
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