2800 LAURA LANE
❘
MIDDLETON, WI 53562
❘
(800) 288-9383
❘
FAX (608) 836-9044
❘
www.tcs-basys.com
16
SERVICE SCREENS
Continually pressing the service status button allows more
extensive monitoring. The screens are shown on the following
page.
Heating or Cooling Does Not Come On
At least one stage of heating is on whenever the heating LED
is on, and at least one stage of cooling is on whenever the
cooling LED is on. If heating or cooling should be on but the
heating or cooling LED is off, check the fan and system
switch modes. Also, check the heating and cooling setpoints,
offsets and differentials, and the room temperature to be sure
heating or cooling should be on. If using outdoor air heating
and cooling lockouts, or discharge air high and low limits,
check their values to be sure heating or cooling is allowed. If
heating or cooling is off, but the corresponding LED is on,
check the wiring. Short terminals “R” to “Y/W1” or “Y/W2”
and see if the heating or cooling comes on. This is a check for
a mechanical relay failure.
Wrong Temperature Display
If any of the temperatures are reading slightly high or low, there
are three adjustment pots located in the cover to adjust them.
“T1” is for the room temperature, “T2” is for the discharge air
temperature, and “T3” is for the outdoor air temperature. If the
temperature is at a minimum or maximum reading, check the sen-
sor dipswitch positions. (See setup instructions.) Check for wiring
problems (opens or shorts). A remote 1000
Ω
sensor should read
108 to 109
Ω
at room temperature.
Service LED is On
If the service LED is on, it may be for monitoring purposes or
it may indicate a critical problem. The first monitoring screen
accessed by pressing the service status button will display why
the light is on.
Outputs Will Not Shut Off
First check the room temperature and the setpoints and deter-
mine whether the output should be on. There are delays and
minimum on and off times for the fan and heating and cooling
stages. Also, check the service status menus to verify that the
outputs are on. Turning the system to “off” will instantly turn
all outputs off. The thermostat can be reset by pressing the
system switch button and the service status button simultane-
ously.
Analog Output Not Working Properly
Check wiring. A separate transformer should be used for the
SZ1017a, SZ1041, SZ1051 or SZ1053, and a separate trans-
former should be used for the motor(s). Check to make sure
that the analog output is programmed correctly.
Check the Service Menu. The Mod Out Screen will tell you
what the SZ1041 or SZ1051 is trying to put out. Compare this
with the actual position on the heating or cooling device.
There are two conditions that must be met before the econo-
mizer analog output will modulate. First, there must be a call
for cooling. Second, the outdoor air temperature must be less
than the setting set in programming step #31b (for the
SZ1041) or #30a (for the SZ1051).
Put the SZ1041 or SZ1051 into occupied mode. You should be
able to adjust the output by going to programming step #35b
(for the SZ1041) or #34a (for the SZ1051) and varying the
minimum position setting. You need to exit programming
before the change will take effect.
MON
72F
12:00 AM
DISCHARGE AIR
55F
OUTDOOR AIR
OVERRIDE
178 MINUTES
75F
SERVICE STATUS
OK
TEMP
1.
2.
3.
4.
5.
TEMP
HEAT STAGE 2
service
status
service
status
service
status
service
status
service
status
service
status
HEAT STAGE 1
COOL STAGE 1
6b.
7b.
COOL STAGE 2
OUTDOOR AIR
DI1
service
status
service
status
MOD OUT 1
6a.
7a.
OUTDOOR AIR
FAN STATUS
service
status
service
status
11-19-01
ON
OFF
OFF
25%
25%
OK
ON
OFF
100%
OPEN
Main Monitoring Screen. Press the ser-
vice button to access the following
screens. (Date not shown on SZ1017a.)
Service Screen. This message may be
followed by any or all of the following:
CHECK FILTER, CHECK FAN, DIS-
CHARGE HIGH, DISCHARGE LOW, or
CHECK DI2.
]Discharge Air Temperature Screen.
Shows discharge air temperature if sen-
sor is used.
Outdoor Air Temperature Screen.
Shows outdoor air temperature if sensor
is used.
Override Status Screen. Shows
whether the override is active and if so,
how many minutes remaining.
Heat or Cool Stages Status Screen.
Shows the status of the first and second
stages of heating or cooling.
Modulating Output 1 and 2 Status
Screen. Shows the percentage of modu-
lating output 1 and 2.
DI1 Status Screen. Shows the status of
the fan interlock or DI1.
Cool Stages Status Screen. Shows the
status of the first and second stags of
cooling.
Damper Position and DI1 Status
Screen. Shows the position of the
damper output and the status of the fan
interlock if DI1 is set for fan interlock.
FOR THE SZ1051
FOR THE SZ1041
