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The software allows you to override the thermostat by putting the
override parameter into the remote mode, and thus disabling the timed
override.
SetBACk And oveRRide APPliCAtionS
In most applications, it is desired to maintain a regular schedule,
and allow timed override with the button on the face or with a remote
momentary contact.
To allow a regular schedule, and also automatically override with the
use of occupancy or light sensor, set DI3 to override and set it up so
that the contact is closed when you want the override.
For applications where a room might not be used on a regular sched-
ule, such as conference rooms, set DI3 to external time clock and
close the contact when you want the room occupied, such as with a
switch or wind-up timer. If each occupancy period is about the same,
(theaters, meetings) another option is to set the DI3 to external time
clock, and use the timed override button to put the unit in occupied
mode.
To make the unit always occupied, set DI3 to external time clock and
short the DI3 terminal to ground.
tWo-PiPe FAn Coil oPeRAtion
For two-pipe fan coil operation, in step #28 select NO. In step #29,
select YES. You must then select whether the system is HEATing only,
COOLing only or heating and cooling (H&C) in step #30.
When using a two-pipe system to do both heating and cooling, the
SZ1063 and SZ1064 need to know whether hot or cold water is avail-
able. This is accomplished by either the use of a mechanical aquastat
(bulb thermostat) connected to terminals DI1 and 24-, or by the use of
a temperature sensor connected to T2 and T2 (SZ1064 only). If using
a mechanical thermostat, select DIGITAL in step #31, and select nor-
mally closed N.C. or normally open N.O. In step #32. If using a tem-
perature sensor, select ANALOG in step #31 and place a changeover
setpoint in step #33. When the temperature is greater than this set-
point, it is assumed hot water is available and heating is done. When
the temperature is less than this setpoint, it is assumed cold water is
available and cooling is done.
When using a two-pipe system to do both heating and cooling, only
AO2 is used. When using a two-pipe system to do only heating, only
AO1 is used. When using a two-pipe system to do only cooling, only
AO2 is used.
thRee-PiPe FAn Coil oPeRAtion
For three-pipe fan coil operation, in step #28 select YES.
Three-pipe fan coil operation assumes that there are two water
sources available (hot and cold), and that the water to the fan coil will
be a mixture of these. Only analog output two is used for three-pipe
operation. The output will be 12mA (4-20mA) when there is no need
for heating or cooling. As there becomes a need for heating or cool-
ing, the analog output modulates toward 4mA or 20mA depending on
whether analog output two is direct or reverse acting.
FoUR-PiPe FAn Coil oPeRAtion
For four-pipe fan coil operation, in step #28 select NO. In step #29,
select NO.
Four-pipe fan coil operation assumes that there are two water sourc-
es available (hot and cold), that are each controlled by its own valve.
Analog output one is used for heating and analog output two is used
for cooling.
PiPe temPeRAtURe SenSing
The SZ1063 and SZ1064 accepts a remote pipe temperature sen-
sor for monitoring purposes or for changeover in a two-pipe system.
(See setup instructions for dipswitch placement for this option.)
The pipe temperature span is 0 to 150°F (-17.8 to 65.6°C).
AnAlog oUtPUtS
The analog outputs on the SZ1063 and SZ1064 are used to control
the heating and cooling in a space. Analog output 1 is used to control
heating and analog two is used to control cooling with a four pipe
system. Only analog output 2 is used with a three-pipe or with two-
pipe system set for heat and cool (H&C).
di2 SetPoint ShiFt
The SZ1063 and SZ1064 allow DI2 to be set for setpoint shift for
energy demand setback. A digital contact that closes when setback
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 setpoint 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 pur-
pose, make sure to set the setpoint shift value to zero.
AUXiliARy RelAy oUtPUt PARAmeteRS
The auxiliary relay of the SZ1064 will control one stage of either
heating or cooling, or can be used as a timeclock output.
If the auxiliary relay is used as heating or cooling stage, you may
specify an offset and a differential value. The offset value is the
amount away from the setpoint a stage will turn off. By assigning a
value other than zero, you "anticipate" that the residual heat or cool-
ing in the duct will bring the temperature back to setpoint. In most
cases, a first stage is set to zero. The differential value is the differ-
ence between the on and off points. Using an offset value greater
than or equal to the proportional band of an analog output will allow
the relay to come on after full modulation is achieved. Strip heat, for
example.
If the auxiliary relay is used as a timeclock output, it is selectable
whether the relay is open or closed during the occupied period.
During the unoccupied period, the opposite will occur.
Keep in mind that although it is an isolated relay (separate common
terminal), it is rated at 24 VAC @ 2A. For loads that exceed this, use
an external relay.
