York J Series User Manual

JOHNSON CONTROLS
22
FORM 100.50-NOM7 (808)
Unit Sequence of Operation
Heating Operation With a Space Sensor
For Heating operation, the space temperature will be
controlled to either the Unoccupied Heating Setpoint or
the Occupied Heating Setpoint based on the Occupied/
Unoccupied state of the unit (i.e. Occ/Unocc Input, or
Internal Scheduling).
Control Algorithm For Space Sensor Staged Heat
• The Space Sensor Staged Heat control algorithm is
as illustrated in Figure 6. The controller will read
the number of Staged Heat parameter to determine
the heat stages available. Heat stages will be used
in number sequence.
• A direct acting, proportional – integral space tem-
perature controller generates a 0 – 100% output
signal that responds to space heating demand.
• The output of the controller is used to calculate on
and o time of the heat step most recently started
based on the calculation method in Figure 6.
FIG. 6 – CV SPACE SENSOR STEPPED HEAT
ALGORITHM
LD06555
Heat Step
Stays OFF
Heat Step
Stays ON
OFF -Time
ON-Time
On-Time
(minutes)
Min.
OFF -Time
(6 minute
s
)
100%
High Saturation
Output of C ooling Zone
Temp. C ontrol (PI)
Low Saturation
0%
Min.
ON-Time
(6 minutes)
OFF -Time
(minutes)
• PI gain values are to be determined by such that all
heating steps are on within 20 minutes with a 10°F
space temperature error.
• When the duty cycle reaches 100% (the PI algorithm
reaches a “High Saturation state” and a saturation
time delay expires), the modulated heating step
stops cycling and remains on.
• An additional heating step is started every time the
space control PI algorithm reaches a high saturation
state and a programmed saturation time delay ex-
pires.
• A heating step is stopped when the PI algorithm
reaches a Low Saturation state and a programmed
saturation time delay expires.
Control Algorithm For Space Sensor
Hydronic Heat
In CV heating operation using hydronic heat, the SAT
is controlled by algorithm as shown in Figure 7.
Table 3 details the modes of CV operation and provides
an overview of the control methods in all modes.
FIG. 7 – CV SPACE SENSOR HYDRONIC HEAT
ALGORITHM
Hydronic Heat
2nd Stage
SAT Setpoint
Hydronic Heat
1st Stage
SAT Setpoint
Zone Satisfied
(No Heat)
-1.5˚F
+0.5˚F +2.0˚F
Zone Tem perature
Setpoint For Heating
Space Tem perature Deviation From Setpoint (˚F)
LD06556

York J Series Specifications

General

Brand	York
Model	J Series
Category	Air Conditioner
Language	English