Types Of Space Sensors - York MILLENIUM SIMPLICITY ELITE Series Technical Application And Programming Manual

TYPES OF SPACE SENSORS

No Sensor-
The system will internally detect the presence of
space sensors.
Sensor with Unoccupied Override Button -
has a Thermistor and an Override button that shorts the Sensor
when pushed. If the Override button is pushed the unit will go
into the Unoccupied Override mode for the Unoccupied
Override Time (note that the control must not recognize the
short as a sensor failure). Once the Unoccupied Override mode
is initiated, it will continue until the programmed Unoccupied
Override Time Limit is reached.
Sensor with Space Setpoint Adjust -
slider potentiometer on it that represents (as a default) +/- 3 °F
adjustment to the Space Setpoint. The Space Setpoint Offset
option. If the unit appears to be controlling at a higher or lower
temperature than the setpoint, check the Space Setpoint Adjust
slider.
SUPPLY FAN CONTROL WHEN USING A ZONE SENSOR
In the Occupied mode, setting of the parameter "Fan ON mode
with the Sensor Option" will determine if the Supply Fan is ON
continuously, or is in "Auto" mode (i.e. cycles with the heating/
cooling cycles). In Unoccupied mode, the fan is always in the
Auto mode.
SUPPLY FAN OFF DELAY
Uses minimum off time.
CONTROL OF COMPRESSORS WHEN USING A ZONE
SENSOR
A Minimum run time of one to ten minutes [default = three]
applies to all compressors. The minimum run time is necessary
to ensure that the oil in the refrigerant circuit circulates back to
the compressor.
The Anti Short Cycle delay of five minutes OFF applies any time
compressor operation is terminated. Compressors are turned
ON and OFF individually during CV operation with a zone
sensor, where the cooling control algorithm is implemented in
the controller (rather than in a thermostat).
The stage groups are applicable only for control of compressors
with external signals, such as from a thermostat.
There is a minimum 30 second delay between compressors
when bringing on multiple compressors.
HEATING OPERATION WITH THE SENSOR OPTION
The space temperature is controlled to a programmed
Unoccupied Heating Setpoint, or to a programmed Occupied
Heating Setpoint, as determined by the internal schedule and the
state of the Occupied Input (if this input is ON during a scheduled
unoccupied time, the unit goes to Occupied Override mode).
The control will use as many as three stages of heat, depending
on what heat option is are installed.
Johnson Controls Unitary Products
A zone heating demand of -1.5 °F will generate a request for
first stage heat.
A zone heating demand of -2.0 °F will generate a request for
second stage heat.
This Sensor
A zone heating demand of -2.5 °F will generate a request for
third stage heat. There is a three minute minimum off delay and
a thirty second delay between stages.
When the zone temperature is -0.1 °F, or less below the zone
setpoint for at least 1 minute, the transition to a satisfied state
occurs, the heating stops and the supply fan either continues
running, or is turned off after SAT drops below 100 °F. The
supply fan control in the satisfied state and in the occupied
This Sensor has a
mode is determined by setting of the programmable parameter
"Fan ON Mode with the Sensor Option". In the unoccupied
mode, the fan is always turned off when the zone is satisfied.
During heating, the SAT control to the selected SAT setpoint is
performed using a PI algorithm. Two minute Minimum Run Time
and Anti Short Cycle delays applies to all heat stages. There is
also a delay of at least one minute between turning on heating
stages.
COOLING OPERATION WITH THE SENSOR OPTION
The control will operate as a two-stage unit.
On two compressor units, compressor one is first stage and
compressor two is second stage.
On three compressor units, compressors one and two are first
stage and compressor three is second stage.
On four compressor units, compressors one and two are first
stage and compressors three and four are second stage.
The control uses a minimum 30-second compressor delay
between compressors when bringing on a stage with multiple
compressors.
A zone cooling demand 1.5
A zone cooling demand 2.0
cooling.
If the unit has a demand greater than 1.5
control will turn on the first compressor of stage one and load a
5-minute timer. If after 5 minutes the Space temperature is not
moving toward the Setpoint, the control will turn on the second
compressor of stage one, if available, and wait 5 minutes. The
control will continue operating first stage until the Space
temperature reaches the Setpoint and then it will turn off the
stage one compressor. If after 5 minutes the Space temperature
is not moving toward the Setpoint, the control will turn on the
first compressor of stage two and wait 5 minutes. The control
will continue to turn on compressors using the 5-minute
trending timer until the Space Temperature begins to move
toward the Setpoint. The control will turn off all the second
stage compressors with a 30-second delay between them when
the demand reaches .5 °F. The control will continue operating
351579-YTS-B-0608
°
makes a call for first stage cooling.
°
makes a call for second stage
°
but less than 2.0
°
, the
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