Johnson Controls York VERSECON YSWD 012, Установка, эксплуатация и обслуживание

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JOHNSON CONTROLS
FORM 145.05-NOM1 (708)
If Supply Air Temperature Control, Return Air
Temperature Control, and Dew Pont Control are
selected; the Unit Control will compare the Supply
Air Temperature Control output to the Return Air
Temperature Control output and select the lower of
the two outputs. It will then compare it to the Dew
Point Control output and select the higher of the two
values.
The 2 to 10 volt analog output is located at the AO-1
terminals 1 and 2 and is used to control the outdoor
and return damper actuator. As long as the outdoor air
economizer is enabled and the unit Air Flow Switch is
closed, the output will never be less than the “O/A MIN
POS” setting.
CONDENSER WATER VALVE OPERATION
The following parameter must be programmed through
the “Setpoints” section of the Keypad / Display or by
a communicated input.
“COND VALVE MIN”
– This value is the minimum
position of the condenser water valve when the unit is
in the active cooling mode. The default value is 15%.
Sequence of Operation
The control monitors the discharge pressure analog
inputs and selects the highest input value. The 0 to 5 volt
analog inputs are found on the I/O Expansion Control
Board at IN-1 – terminals 1 and 2 for compressor A, IN-
3 – terminals 5 and 6 for compressor B, IN-5 – terminals
9 and 10 for compressor C, and IN-7 – terminals 13 and
14 for compressor D.
The control compares the highest discharge pressure
input value to the 180 psig set point and generates a
demand percentage based on the difference and the
amount of response to a given change in output. When
the control generates a 0% demand, the control will
output a 10 VDC output at AO-4, Terminals 7 and 8.
This output controls the operation of the condenser
water valve. When the control sees a 100% demand,
the control will output a 2 VDC output.
While the unit is in the active cooling mode the output
to the condenser water valve cannot drop below the
“COND VALVE MIN” set point.
CONDENSER WATER BYPASS
The following parameter must be programmed through
the “Setpoints” section of the Keypad / Display, or by
a communicated input.
“BYPASS VALVE MAX” – this is the maximum position
of the condenser water by-pass valve. The default value
is 50%.
If waterside economizer is not used, the water side
economizer valve can be used as a condenser water
bypass valve. This feature must be ordered from the
factory.
Sequence of Operation
The factory programmed value for the maximum
allowable bypass is 50%. The output to the condenser
water bypass valve is inversely proportional to the
output to the condenser water valve. For example, if
the condenser water valve output is at 0% the output to
the condenser water bypass valve would be maximum
allowable bypass, factory set at 50%. If the condenser
water valve is at 20%, the condenser bypass valve would
be at 40%. If the condenser water valve is at 50%, the
condenser bypass would be at 25%.
The 2 to 10 volt analog output to the condenser water
bypass valve is located at the AO1 – terminals 1 and 2
of the main control board.
MECHANICAL COOLING OPERATION
The following parameters must be programmed through
the “Setpoints” section of the Keypad / Display or by
a communicated input.
“AC-S/A TEMP EN” – The unit can control the
operation of the cooling function by either the supply
air temperature or the return air temperature, or both. If
supply air control is desired, this value must be turned
ON. ON is the default value.
“AC / ECON S/A SP” – This is the set point the
controller will control to if the unit is configured for
“AC-S/A TEMP EN”
, the default value is 55.0° F.
“AC-R/A TEMP EN” – The unit can control the
operation of the cooling function by either the supply
air temperature or the return air temperature, or both.
If return air control is desired, this value must be turned
ON. OFF is the default value.
“AC / ECON R/A SP” – This is the set point the
controller will control to if the unit is configured for
“AC-R/A TEMP EN”
, the default value is 75.0° F.
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