Honeywell Micronik 200 Specification Data page 4

R7426A TEMPERATURE CONTROLLER
FUNCTIONS
Real-Time Clock
The time clock performs automatic change of the controller
mode to OFF, Night, Standby, or Comfort in accordance with
the programmed time schedule. In Standby or Night mode,
the SOFFS or NOFFS is added (cooling) to or subtracted
(heating) from the calculated control point. Schedules for one
week and up to six switching points per day can be pro-
grammed in advance and repeated week after week. In
addition, three different holiday schedule types H1, H2, and
H3 can be programmed. One of these holiday types can be
assigned to each holiday date of the year (01.01. ... 31.12.).
Holiday types H1 and H2 are valid only for this specific day
and are reset to normal time schedule at midnight of that day.
H3 is valid for every year and repeated year after year for
fixed holiday dates. H1 can be programmed to be in OFF
mode the whole day and H2 to be ON for a short period of
time on the last day of a longer holiday period to preheat or
precool the space in advance before the first occupied day.
Optimum Start Program
The optimum start program's objective is to minimize total
energy consumption by calculating in room control appli-
cations the start time for heating or cooling mode which will
bring its respective space temperature to the boundary of the
comfort zone at the time of occupancy start. The optimum
start program uses historical data for self-adaptive
adjustment.
Night Cycle Program
The night cycle program offers not only energy conservation,
but also the ability to assign
limits with 1K hysteresis for the protection of a space and its
contents against temperature extremes. It automatically
cycles between the user selected upper and lower limits and
turns on full heating or cooling whenever the limits are
reached.
APPLICATION
NOTE: All diagrams show proportional control action, only.
If P+I control is in operation, the slopes for heating
and cooling are not defined.
Main Temperature Control
The controller compares the actual temperature value
measured by the main sensor (T1) with the calculated
Y1
Heating
100%
0
EN0B-0299GE51 R0104
OFF mode night low or high
Cooling
0
X
w
CTRP1 T1
C
Y
start
Xp1
setpoint (CTRP1) and generates an internal deviation signal
(X ). CTPR1 is the sum of the OAT compensation effect, the
w
CPA, and the mode-dependent offset.
Depending on the deviation signal, the control output (Y1)
value is calculated and converted to a floating signal. Cooling
or heating action is selected by the configuration parameter
Y1CRTF. The ''Throttling range'' setting (Xp1) controls the
output span.
The startpoint Y determines (in Kelvin) the midrange shift
start
of the output (Y1) from the calculated setpoint (CTRP1).
Limit Control (Wlim, Xp2, and tr2)
The R7426A controller offers limit control (W
performed by comparing the deviation signals of the main
and limit control loops. The lowest (low limit control) or
highest (high limit control) deviation signal is selected and
fed into the output stage.
High limit control is performed if control parameter
LimTyp = 1 and low limit control is performed if control
parameter LimTyp = 0. During limit control, the throttling
p
range (X 2) and reset time (tr2) are active.
Limit control will be active only if the T2 temperature sensor
(control parameter T2ext = 0) is connected or alternatively
the sensor T1 value (control parameter T2ext = 1) is used
also for the limit control loop.
Cascade Control (W
The R7426A controller provides cascade control, which uses
two control loops (master and submaster) to maintain the
master setpoint (CTRP1).
At zero room temperature deviation (X
charge temperature (T2) is controlled by the programmed
setpoint (W = CTRP2). If the room temperature deviates,
cas
the submaster setpoint (CTRP2) is altered.
The reset span adjustment (R
reset effect.
T1 C
Xp
CTRP1
CTRP2
W
lim
R
cas
W
cas
R
cas
W
lim
4
) which is
lim
, R and tr2)
cas cas
Master), the dis-
W
) determines the degree of
cas
MASTER
0 X Master
w
SUBMASTER
for
LimTyp=1
for
LimTyp=0
X Master
0
w