TCS SZ1025b User manual

2800 Laura Lane Madison, WI 53562 | 800.836.9044 Fax: [phone] | www.tcsbasys.com v0717.2
The SZ1025b is a microprocessor-based
controller designed for VAV terminal unit
applications.
SZ1025b
VAV Box Controller
|PRODUCT MANUAL

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TABLE
OF CONTENTS
Manual Key
Table of Contents
Caution: Requires special attention.
Note: Something you should know.
The following symbols are used throughout this document. Their meanings are as follows:
Manual Key .............................................2
Features ................................................3
Mounting ...............................................3
Wiring ..................................................4
Setup ..................................................5
Programming ...........................................5
Sequence of Operations ..................................10
Checkout & Troubleshooting ..............................10
LED Description .........................................12

2800 Laura Lane Madison, WI 53562 | 800.288.9383 Fax: [phone] | www.tcsbasys.com 3
Features
Mounting
• Stand-alone or network operation
• Built-in velocity pressure sensor with K-factor
correction
• Pressure dependent or pressure independent
operation
• Capable of controlling series or parallel fan-powered
boxes
• Offers two independent modulating outputs
• Adjustable PID control of modulating outputs
• Interface available for tri-state actuator motors (QE25)
• Separate heating and cooling minimum and maximum
CFM settings
• Four independent dry contact outputs
• Remote setpoint capability
• Discharge air sensor input
• Filter monitor input
• External time clock input
Use two #10 sheet metal screws to mount the SZ1025b.
For best results, the room sensor should be mounted on an interior wall that reects normal room environment, at a
height of approximately ve feet from the oor. Avoid areas exposed to direct sunlight, unusual heat sources, open doors
and windows, or unventilated locations.

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Wiring
The SZ1025b terminal designations are shown below.
Remote Sensor Wiring
The SZ1025b accepts two 1000 Ω two-wire platinum
RTD sensors. Use TS2000 or TS3000 for room sensing,
TS2023a for analog room sensing with setpoint
adjustment, PX1060 or equivalent for digital room
sensing with setpoint adjustment and TS1009 or
TS1002 for duct sensing. When using TCS Basys
Controls three-wire RTD sensors, use the black and red
leads, and either clip or twist off the white lead. The
wiring length from the room sensor to the SZ1025b
should not exceed 250 ft.
Powering the SZ1025b
The SZ1025b is powered from 24 VAC +/- 10 %. If
wiring for communications, dedicated power must
be used to power the SZ1025b. Several S-series
thermostats may be powered from the same
transformer, provided that the transformer has
enough power.
Caution: When multiple TCS Basys Controls
devices are using a single transformer, the
polarity of the power wiring must be
maintained because all TCS devices are
half-wave rectied.
TS2023a wiring to
SZ1025b
Optional QE25 Tri-state interface wiring
PX1060 wiring to SZ1025b
Twisted, Shielded 18 AWG. Must be run separately.
24AC transformer. The SZ1025b power must be dedicated.
If using TS2000 or TS1009, use red and black leads. If using
PX1060 sensor connect to T1 left terminal.
4 to 20mA output. 600 Ohm max. Do not power actuators with
SZ1025b power. The SZ1025b is half-wave recried, where by
the power ground is common with the signal ground.
Dry contact. Must not be powered.
Dry contact rated 24 VAC @ 2A. Do not power relay with SZ1025b
power.
If not using TS2023a setpoint adjustment pot., you must short SP
to GND.
12VDC power for digital setpoint adjust sensor (PX1060) with
wiring to setpoint pin (SP).
1
2
3
4
5
6
7
8
+5V
SP
GND
8
8

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Setup
PRESSURE CONNECTIONS
For pressure inde-
pendent applications,
the SZ1025b provides
a velocity pressure
transducer. To utilize
this, connect the high
port on the SZ1025b
to the air flow measur-
ing station port or pitot
tube port that faces
the flow. Connect
the low port on the
SZ1025b to the air
flow measuring station
port or pitot tube port
that faces away from
the flow.
USING TRI-STATE ACTUATORS
If using tri-state instead of 4 to 20 mA, actuators a
QE25 transducer is available. To connect the QE25 to
the SZ1025b, use the ribbon connector included with
the QE25 as shown, in the wiring section.
The SZ1025b may be programmed through the display
and keypad, or with a PC.
If programming with a PC, the following must be set
through the keypad prior to programming:
• Address (step #2)
• Baud rate (step #3)
For more information on programming through the PC,
consult your TCS software manual.
Programming through the Keypad
To access the programming screens, press both the
“Scroll” and “Next” keys simultaneously.
Scroll Key - The "Scroll" key is also used to save any
changes to the "current" screen and advance
to the next screen while programming. The
"Scroll" key is used to enter the Programming
Mode when pressed with the "Next" key.
Next Key -
Used to enter Programming Mode when
pressed with the “Scroll” key. Also used to exit
programming without saving changes to the cur-
rent screen.
Increment/Decrement Keys -
Used to select the desired value.
Programming
Zone temp
71F
Main Monitoring Screen. Press the
scroll and next buttons to access the
following screens.
Access Code Entry Screen. Enter
the access code. If the wrong code
is entered, the prorm reverts to the
main screen. 248 is the default access
cose.
Controller Address Screen. If using a
PC to access the SZ1025b, set a unique
address from 0 to 255, excluding 248.
Communication Baud Rate Screen. If
using a PC to access the SZ1025b, all
contollers on a network must be set to the
same baud rate. Choose between 2.4K,
4.8K, 9.6K and 19.2K.
Temperature Selection Screen.
Select whether youwant to show Deg.
Fahrenheit or Celsias.
Shared Temperature Enable Screen.
Sharing zone temperature with another
SZ1025b (2 max.) Select YES if not
select NO.
Zone Temperature Calibration Screen.
A calibration factor (+/- 25°F) for zone
temperature Input.
Supply Temperature Calibration
Screen. Enter a calibration factor (+/-
50°F) for supply temp Input.
Pressure Calibration Screen. Enter a
calibration factor (+/- 0.50WCD) for
pressure.
Setpoint Low Limit Value Screen. Enter
a setpoint low limit value. The setpoint
will not be allowed to be set lower than
this setting.
+
ENTER ACCESS
CODE 000
1.
SET ADDRESS:
000
2.
SET BAUD RATE:
9.6k
3.
TEMPS SHOWN IN:
FAHRENHEIT
4.
ENABLE SHARED
TEMP INPUT? NO
5.
CALIBRATE ZONE
TEMP. 0F
6.
CALIBRATE SUPPLY
TEMP. 0F
7.
CALIBRATE
PRESSURE 0.00 WCD
8.
SETPOINT LOW
LIMIT: 40
9.

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J-FACTOR:
NORMAL
15. J-factor Screen. Select if Normal or
Inverted. J-factor will be used.
K-factor Screen. Enter a "K" factor, if
appliciable.
Duct Screen. Enter wheater the VAV
duct is Round or Rectangular.
Duct Size Round. Enter diameter in
inches.
Duct Size Rectangular. Enter the height
in inches.
DUCT
ROUND
17.
DUCT
DIA METER: 9.0
18.
DUCT SIZE
HEIGHT: 9.0
19.
DUCT SIZE
WIDTH: 6.0
20.
AO1
ACTION: DIRECT
21.
AO1
CHOICE: MODULATING
22.
AO1 MODE
IS: HEAT
23.
HT/COOL
SETPOINT: 70
24.
IF RECTANGULAR
SELECTED GO TO
STEP 13.
AO1 CFM
PROP BAND: 10%
26.
AO1 OUTPUT
RANGE: 4-20mA
27.
DAMPER:
PRE DEPENDENT:
28.
AO1 TEMP
PROP BAND: 8%
25.
K-FACTOR:
1.00
16.
Analog Output/Temperature
Proportional Band. Enter in the % or
input span (40 to 90) the number of
degrees away from setpoint + deadband
that the device will be fully open.
Analog Output/CFM Proportional
Band. Enter in the % or input span (0 to
1" WCD) the cfm proportional band.
Analog Output/Output Range. Choose
whether the output range will be 0-20mA
or 4-2omA
for Pressure Indepentant you must
program CFM min and max values via
software
Damper Screen. Enter whether the
damper control should be pressure
dependant or pressure independant.
If pressure indepentant is selected skip
to step 28
Setpoint High Limit Value Screen. Enter
a setpoint high limit value. The setpoint
will not be allowed to be set higher than
this setting.
Setpoint Source Screen. Select wheth-
er you are using a RTD3 or Remote
Setpoint.
Setpoint Screen. Enter a setpoint value
for control. (This screen does not appear
if Remote Setpoint is programmed in
software).
Occupied Deadband Screen. Enter an
occupied deadband. This is +/- the set-
point where no control is done, during the
occupied time period. This is a number
from 0 to 100% of input span.
Unoccupied Deadband Screen. Enter an
unoccupied deadband. This is +/- the set-
point where no control is done, during the
unoccupied time period. This is a number
from 0 to 100% of input span.
SETPOINT HIGH
LIMIT: 90
10.
SETPOINT SOURCE:
RTD3
11.
SETPOINT
LOCAL: 72
12.
OCCUPIED
DEADBAND: 01%
13.
UNOCCUPIED
DEADBAND: 5%
14.
Duct Size Rectangular. Enter the width
in inches.
Analog Output 1 Action Screen. Choose
whether the output will be
direct or reverse acting. (If output is
programmed for Ht/cbol mode the output
will automatically reverse action)
Analog Output 1 Choice Screen. Choose
whether the output will be
modulating (AO1) or floating (NO5/NO6).
Analog Output 1 Mode Screen. Choose
whether output will be used for COOL,
HEAT or HT/COOL.
Ht/Cool Supply Setpoint Change Over
Screen. Enter the supply air temperature
at which you wish to change from heating
to cooling or vice versa (this screen will
not show if AO1 mode is not set for HT/
COOL).

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COOL MINIMUM POSITION:
0%
29.
COOL MAXIMUM POSITION:
80%
30.
HEAT MINIMUM POSITION:
10%
31.
HEAT MAXIMUM POSITION:
100%
32.
AO1 MOTOR
TIME: 1.5 MIN
33.
AO2
ACTION: DIRECT
34.
AO2
CHOICE: MODULATING
35.
AO2 MODE
IS: COOL
36.
AO2 SETPOINT
OFFSET 0.0
37.
AO2 PROP
BAND: 10%
38.
AO2 OUTPUT
RANGE: 0-20mA
39.
AO2 MOTOR
TIME: 1.5 MIN
40.
STAGE 1
DIFF: 2F
43.
STAGE 2 MODE
AS: COOL
44.
STAGE 2
OFFSET: 0F
45.
STAGE 2
DIFF: 2F
46.
Pressure Dependant Screen. Enter in %
the min cooling damper position.
Pressure Dependant Screen. Enter in %
the max cooling damper position.
Pressure Dependant Screen. Enter in %
the min heating damper position.
Pressure Dependant Screen. Enter in %
the max heating damper position.
Enter floating motor time in min.
Anolog Output 2 Action Screen.
Choose whether the output will be direct
or reverse acting.
Anolog Output 2 Choice Screen.
Choose whether the output will be modu-
lating (AO2) or floating (NO7/NO8).
Anolog Output 2 Mode Screen. Choose
whether the output will be used for heat-
ing or cooling.
Anolog Output 2 Setpoint Screen.
Enter the number of degrees you wish to
offset the output from setpoint.
Anolog Output 2 Proportional Band
Screen. Enter in % of input span (40 to
90) the number of degrees away from
setpoint + deadband the offset that the
device will be fully open.
Anolog Output 2 Output Range Screen.
Choose wether the output range will be
0-20mA or 4-20mA.
Enter floating motor time in min.
Stage 1 Mode Screen. Select wether the
relay control: HEAT, COOL, or FAN.
Stage 1 Offset Screen. Enter an offset
valve for Stage 1.
Stage 1 Differential Screen. Enter a dif-
ferential value for Stage 1.
Stage 2 Mode Screen. Select wether the
relay control: HEAT, COOL or TCLK.
Stage 2 Offset Screen. Enter an offset
valve for Stage 2.
Stage 2 Differential Screen. Enter a dif-
ferential value for Stage 2.
STAGE 1 MODE
AS: HEAT
41.
STAGE 1
OFFSET 0F
42.

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REQUIRE CODE FOR
PROGRAMMING? YES
53.
SET ACCESS
CODE: 000
54.
ZONE TEMP
71
Stage 3 Mode Screen. Select wether
the relay control: HEAT, COOL, FAN,
or OCC functions.
Stage 3 Offset Screen. Enter an off-
set valve for Stage 3.
Stage 3 Differential Screen. Enter a
differential value for Stage 3.
Stage 4 Mode Screen. Select wether
the relay control: HEAT, COOL, FAN,
or OCC functions.
Stage 4 Offset Screen. Enter an off-
set valve for Stage 4.)
MOTOR TIME
Enter the “Motor Time” in minutes if you choose that the
actuator is “floating or tri-state”. Larger times will slow
down the response and smaller times will speed up the
response. The number of minutes is from 1 to 10 min-
utes. We recommend to use the speed actuator takes to
go from fully open to fully closed.
STAGE 3 MODE
AS: FAN
47.
STAGE 3
OFFSET: 0F
48.
STAGE 3
DIFF: 1F
49.
STAGE 4 MODE
AS: OCC
50.
STAGE 4
OFFSET: 0F
51.
STAGE 4
DIFF: 1F
52.
not yet implemented v.2.05
NO4 Differential Screen. Enter a
differential value for Stage 4.
Programming Access Screen.
Choose whether or not a code will be
required to enter programming setup.
Access Code Screen. Enter an
access (0 to 255) code that will be
used to enter the programming and/or
clock and schedule setups if access
code had been rrequired in the last
two steps. The default is 248.
Main Monitoring Screen.
AUXILIARY RELAYS STAGE 1&2
Select the mode for which can be “Heat” or “Cool” con-
trol, and for Stage 3&4 which can be “Heat” or “Cool”
control, "FAN" controls or for an external time clock “Occ”
signal.
For a “Cooling” output, the relay energizes when the
input equals the “Setpoint” + “Deadband” + “Offset” +
“Differential and de-energizes when the input falls to the
“Setpoint” + “Deadband” + “Offset.”
For a “Heating” output, the relay energizes when the
input equals the “Setpoint” - “Deadband” - “Offset” -
“Differential and de-energizes when the input rises to the
“Setpoint” -“Deadband” - “Offset.”
For “Fan” control, the relay is energized during the occu-
pied time and energized on a call for heat or cool during
the occupied time.

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HEAT COOL HT/CL
AO1 PRESSURE DEPENDENT MODE
max%
Room Temp (F)
20
12
4P(temp)
SP+DB
=min%
max%
cool
Room Temp (F)
20
12
4P(temp)
SP+DB
=min%cool
SP-DB
=min% heat
max%
heat
SP-DB
=max%
Room Temp (F)
20
12
min%
SP-DB
=max%
Room Temp (F)
20
12
4P(temp)
min% max%
Room Temp (F)
20
12
4P(temp)
SP+DB
=min%
min%
cool
Room Temp (F)
20
12
4P(temp)
SP+DB
=max%cool
SP-DB
=max% heat
min%
heat
2nd RTD > 70 F
P(temp)
2nd RTD < 70 F
P(temp)
2nd RTD > 70 F
2nd RTD < 70 F
P(temp)
4
Modulating Output AO1
Direct Acting
Reverse Acting
mA Output
mA Output
mA Output
mA Output
mA OutputmA Output
2nRTD < 70F
2nRTD > 70F
2nRTD < 70F
2nRTD < 70F
CFM SETPOINT DETERMINATION Output
Direct Acting Reverse Acting
DB
Room Temp (F)
SP
Max.
Cooling CFM
P(temp)
DB
Min.
Cooling CFM
DB
Room Temp (F)
SP
Max.
Heating CFM
P(temp)
DB
Min.
Heating CFM
CFM SP
CFM Measured
20
12
4P(CFM)
CFM SP
CFM Measured
20
12
4P(CFM)
CFM SP
CFM Measured
20
12
4P(CFM)
CFM SP
CFM Measured
20
12
4P(CFM)
CFM SP
CFM Measured
20
12
4P(CFM)
CFM SP
CFM Measured
20
12
4P(CFM)
AO1 PRESSURE INDEPENDENT MODE
DB
2nd RTD > 70 F
Max.
Cooling CFM
Min.
Cooling CFM DB
Room Temp (F)
SP
Max.
Heating CFM
Min.
Heating CFM
2nd RTD < 70 F
P(temp)P(temp)
HEAT
COOL
HEAT/COOL
CFM Setpoint
Generated
CFM Setpoint
Generated
CFM Setpoint
Generated
mA Output mA Output
mA Output mA Output
mA Output
mA Output
2nd RTD > 70F
2nd RTD < 70F
AO1 Pressure Independent Mode

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Zone Temperature
Zone Temperature
HEAT COOL FAN OCC
In the occupied mode, the
relay is closed.
In the unoccupied mode, the
relay is open.
In the occupied mode, the fan
is on.
The unoccupied fan sequence
is shown below.
DO5 AND DO6 MODES
Differential
Offset
Deadband
Setpoint
On Point
Off Point
OFF
ON
Deadband
Offset
Differential
Setpoint
Off Point
On Point
OFF
ON
Setpoint
Deadband
Deadband
ON
ON
OFF
Digital Outputs NO15 and NO2
Zone Temperature
Digital Outputs NO1 and NO2
SEQUENCE LEGEND
SP=Setpoint
DB=Deadband
P(temp)=Temperature Proportional Band
P(CFM)=CFM Proportional Band
MODULATING OUTPUT AO1
For pressure independent systems, a CFM setpoint is
generated based on: temperature proportional band,
sensed temperature and the temperature setpoint. The
control output is dependent on the CFM proportional
band, CFM measured and the CFM setpoint that has
been generated. For pressure dependent systems, the
control output is based on the temperature proportional
band, sensed temperature and the temperature setpoint.
TRIACS DO1, DO2, DO3, DO4
The SZ1025b can be configured for floating damper and/
or valve motors when used with the QE25 interface. The
CW1 provides clockwise rotation to open the damper
motor.
The CCW1 provides a counter-clockwise rotation to close
the damper motor. The power that CW1 and CCW1 pro-
vide to the damper motor must not exceed 200 mA.
The CCW2 provides clockwise rotation to open the valve
motor. The CCW2 provides a counter-clockwise rota-
tion to close the valve motor. The power that CW2 and
CCW2 provide to the valve motor must not exceed 200
mA.
1. Be sure to check and verify all wiring before powering
the SZ1025b.
2. Turn power on. The SZ1025b display LED should
light up.
3. If the SZ1025b has not been pre-programmed, it
should be programmed at this time.
4. Increase the setpoint on the analog (TS2032a) or digi-
tal (PX1060) zone sensor. Observe the damper opera-
tion and heating stage(s) if used.
5. Decrease the setpoint on the analog (TS2032a) or
digital (PX1060) zone sensor. Observe the damper
operation and cooling stage(s) if used.
6. Note that the operation of the SZ1025b will depend on
how it is programmed.
The SZ1025b is now ready for operation.
TROUBLESHOOTING
No Display
Check for 24 VAC on terminals “R” and “C”.
No communication
Make sure baud rate selection jumper for the QD1010 is
the same as programmed in the SZ1025b.
No communication while connected to TS2023a
When a QD1010 is connected to a PX1060 or TS2023a,
the QD1010 must be powered with the external power
supply supplied with the QD1010. The TS2023a or
PX1060 does not provide power on the phone connector.
Inputs do not read correctly
If not using a setpoint input, SP must be shorted to
GND. For the room temperature and supply air temper-
ature readings, slight adjustments can be made in via
software. For different pressure readings, make slight
adjustments to the zero port which is the middle pressure
pot located closest to the high pressure port fitting.
Output operation is not correct
Check programmed parameters. In particular check
“Reverse” and “Direct” acting selections for the damper
and valve and offset and differential selections for the
relay outputs. Check wiring.
Sequence of Operations
Checkout & Troubleshooting