reset ratio factor. This is the number of degrees that
the discharge air setpoint is raised when the room tem-
perature falls below the heating setpoint by 1 degree if
the analog output is set for heating, or the number of
degrees that the discharge air setpoint is lowered when
the room temperature rises above the cooling setpoint by
1 degree if the analog output is set for cooling.
oUtdooR AiR temPeRAtURe SenSing
The SZ1041A accepts a remote outdoor temperature
sensor for monitoring purposes. (See setup instructions
for dipswitch placement for this option.)
Choose YES in programming screen #37 only if you are
using an outdoor air sensor and you want to enable the
outdoor air heating and cooling lockout functions. If NO
is chosen, the outdoor air is still monitored.
When the function is enabled, COOLING LOCKOUT
TEMP and HEATING LOCKOUT TEMP are entered
in steps #38 and #39. If the outdoor air temperature
falls below the COOLING LOCKOUT TEMP, all cooling
stages will be locked out and will remain locked out until
the outdoor air temperature rises 2° above the lockout
temperature. If the outdoor air temperature rises above
the HEATING LOCKOUT TEMP, all heating stages will
be locked out and will remain locked out until the outdoor
air temperature falls 2° below the lockout temperature.
The outdoor air span is -40 to 160 °F (-40.0 to 71.1 °C).
FAn PRoving
The SZ1041A allows DI1 to be set for fan proving to pro-
tect equipment on fan failure. To utilize this, a pressure
or current switch is required, which indicates when the
fan is running. If the thermostat turns on the FAN, and
DI1 is not closed after thirty seconds, the system will go
to OFF, disabling all outputs, the fan LED will turn off
and the service LED will be lit until the system is manu-
ally reset by switching the system to a mode other than
OFF.
di2 SetPoint ShiFt
The SZ1041A allows
DI2 to be set for set-
point shift for energy
demand setback. This
is enabled by setting
DI2 to the MONITOR
mode. A digital contact
that closes when set-
back is needed should
be wired into DI2. You
may specify a number
of degrees such that,
when the thermostat is
operating in the occu-
pied mode, and DI2 is closed, the heating setpoint will
be lowered this number of degrees, and the cooling set-
point will be raised this number of degrees. The fan will
continue to operate according to its occupied setting. If
you are using DI2 as monitor for another purpose, make
sure to set the setpoint shift value to zero.
R
2800 LAURA LANE • MIDDLETON, WI 53562 • (800) 288-9383 • FAX (608) 836-9044 • www.tcsbasys.com
10
StAge oUtPUt PARAmeteRS
The SZ1041A will control up to two stages of either heat-
ing or cooling. The SZ1041A will control two stages of
heating and two stages of cooling.
For each stage, you may specify an offset and a differ-
ential value. The offset value is the amount away from
the setpoint a stage will turn off. By assigning a stage a
value other than zero, you “anticipate” that the residual
heat or cooling in the duct or the other stages will bring
the temperature back to setpoint. In most cases, the first
stage is set to zero. The differential value is the difference
between the on and off points.
Unlike most other multi-stage programmable thermostats,
the Superstat allows independent adjustments of "offsets"
and "differentials" for stages of heating and cooling. The
offset settings can be viewed as setpoints for the second
and third stages and are programmed in the Superstat in
the number of degrees (i.e. 1,2,3…) beyond the heating
and cooling setpoints (temperatures to be maintained).
The differential for each stage can be viewed as the
"anticipator" function used in mechanical thermostats.
P+i oPtion
The SZ1041A also have a P+I option. Without enabling
this option, stages turn on and off based on temperature
vs. setpoint alone, as described above. By enabling this
option, you add a time factor to anticipate heating and
cooling.
AnAlog oUtPUt PARAmeteRS
Use programming steps #48 through #58 to program the
operating parameters for the analog output. Select wheth-
er the analog output is set for heating, cooling or econo-
mizer. Select direct or reverse action. Select whether you
want the analog output to modulate from 4 to 20mA or
0 to 20mA. Select the unoccupied action ("20mA or 0 /
4mA" will hold the analog output device open or closed
during unoccupied times. "Modulating" will modulate the
analog output device to maintain the unoccupied heating
or cooling setpoint.). Enter a proportional band (throttling
range) in degrees. Enter a setpoint offset in degrees.
heat
Setpoint
Cool
Setpoint
on
on
on
on
oFF
oFF
oFF
oFF
differential
differential
offset
offset
differential
differential
4 20
4 20
4 20
4 20
4 20
4 20
P
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T
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m
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Output
(m A)
P
Output
(m A)
diReCt ACting
ReveRSe ACting
P
P
Output
(m A)
Output
(m A)
Z
o
n
e
T
e
m
p
P
P
Output
(m A)
Output
(m A)
P
P
Z
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CSP
CSP
hSP
hSP
CSP
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