heat-timer Digi-Span TSC Pressure Manual

1
Model TSC/TSR Pressure
Model COC Pressure
INSTALLATION/OPERATING INSTRUCTIONS
Two Stage Set Point Control
Ranges 0 - 30, 0 - 100, and 0 - 200 psi
Warning: This Heat-Timercontrol is strictly an operating control; it should never be used as a primary
limit or safety control. All equipment must have its own certified limit and safety controls required by local
codes. The installer must verify proper operation and correct any safety problems prior to the installation
of this Heat-Timer control.
LIMITED ONE YEAR WARRANTY
This Heat-Timer device was thoroughly tested for defects and workmanship before leaving our factory. We do warrant the equipment to
be free of defects under normal use for a period of one year from the date of installation. Transportation charges for factory repairs must
be prepaid. Damage to the Heat-Timer device or any of its components due to misuse, abuse, improper installation, or caused by power
failures, fire, flood, or lightning are not covered by this warranty. The company assumes no liability for indirect or consequential damages
of any nature. This Heat-Timer warranty applies only to the original purchaser/user, is not assignable or transferable, and does not cover
damage to the device occurring in shipment. Any service, repairs, modifications or alterations to the unit not expressly authorized by the
company will invalidate the warranty. This warranty is in lieu of all other warranties expressed or implied.
R
Blue
Blue
Black
Black
Red
Red
OUTPUT
UP
DOWN
PRESS TO READ
Output 1
Digital display reads
sensor value constantly
To power with
120VAC connect
to these wires
To power with 24VAC
connect to these two
terminals
Red light indicates
output status
Push these buttons to
adjust the settings
Push this button to display
the set points, differential
and offset
Output 2
SENSOR 24VAC
+
_
Black Red
Wire to 0-30, 0-100 or 0-200 psi pressure
transducer observing the polarity
= Set Point 1
= Set Point 2
= Differential
= Offset
= Shorted Sensor
= Open Sensor

2
INSTALLATION
Mounting the Controller
 The Digi-Span is designed to mount on a 1900 (4x4) electrical box.
 If the Digi-Span is to be panel mounted, or if additional room is needed for wiring, an extension skirt is available*.
 Locate the Digi-Span in a convenient location near the unit to be controlled.
 Mount the Digi-Span away from excessive heat or cold. Ambient operating temperature is from 20 to 120°F.
 After completing all the wiring connections (see below) use the two screws provided to mount the Digi-Span to the 1900 box.
Installing the Pressure Sensor
Attach a 1/4 brass isolation tube (pigtail) to the steam header.
 Screw the pressure sensor to the pigtail. The sensor has 1/4"NPT tapered threads.
 The BLACK and RED sensor wires can be extended up to 500 by splicing with 18 gauge shielded wire. Any other sensor
wires (green, white, or shield) and the tube are not used and do not need to be extended.
 Do not run wires in conduit with line voltage.
 The Digi-Span will operate based on the pressure it reads at the sensor location. Therefore, select a sensor location which is
representative of the entire system.
Wiring the Sensor
 The BLACK wire from the pressure transducer should be connected to the terminal marked SENSOR -.
 The RED wire from the pressure transducer should be connected to the terminal marked SENSOR +.
 The transducer wires can also be connected to the back of the Digi-Span using the Rear Wire connector*. Connect the
BLACK sensor wire to yellow Rear Wire and the RED sensor wire to the orange Rear Wire.
Wiring the Power - Digi-Span can use either 120VAC or 24VAC
120VAC
 Attach line voltage to the two blue wires extending from the back of the Digi-Span.
 Use wire nuts, or wrap the connections with electrical tape.
 Class 1 voltages must enter the enclosure through a different opening from any Class 2 wiring.
24VAC
 Use a dedicated transformer with at least a 5VA output.
 Bring 24VAC to the two screws on the front of the Digi-Span marked 24VAC.
 24VAC can also be connected to the rear of the Digi-Span using the Rear Wire connector*. Connect the 24VAC to the violet
and gray Rear Wires.
WARNING
The Digi-Span can accept only one source of power: 120VAC or 24VAC. If more than one power source is
applied, the unit may be damaged.
Wiring the Output
 The Digi-Span has two SPST (single pole single throw) relay outputs rated at 10A, 1/8 HP.
 The outputs are dry contacts only. They do not source any power.
 The Black wires are the N.O. (normally open) contacts for Output 1.
 The Red wires are the N.O. (normally open) contacts for Output 2.
 If the outputs are carrying any Class 1 voltages, then they must enter the enclosure through a different opening from any
Class 2 wiring.
*The Optional Mounting Kit includes the extension skirt, the Rear Wire connector with four wires (orange, yellow, violet, and
gray) and an input terminal cover. Order separately as HT #908520.

3
Setting the Operating Modes
 Whenever the Digi-Span is powered up, it will display the software version number and then the current operating modes.
Each display will remain on the screen approximately 5 seconds. If the modes are correct, there is no need to make any
adjustments.
 Once the modes have been set for a particular application, they will be retained in memory and will not need to be reset.
 Note that if you do change an operating mode, you will need to reset the set points, differential and offset.
 An operating mode can only be changed when it is being displayed in the start-up sequence. To restart the sequence it is
necessary to remove power to the Digi-Span and then power it again.
 Set the operating modes as described in sequence below:
30, 100, or 200 - Pressure Range
 If the display shows 30 then the range will be from 0 to 30 psi and the display will be in 0.5psi increments. If the display
shows 100 or 200, the range will be 0 to 100psi or 0 to 200psi and will display in one pound increments.
 To change the range, hold down the center button while pushing either the UP or DOWN button to toggle between ranges.
 When the range is selected, release the buttons and wait approximately 5 seconds.
H or C- Heating or Cooling (TSC/TSR only)
 If the display shows H then the Digi-Span will be in a heating mode. The relays will close when the pressure is below the set
point (see Example on pg.6)
 If the display shows Cthen the Digi-Span will be in a cooling mode. The relays will close when the pressure is above the set
point.
 To change the mode, hold down the center button while pushing either the UP or DOWN button to toggle between the
displays of Hand C.
 When the correct heating or cooling mode is selected, release the buttons and wait approximately 5 seconds.
TSC or TSR - Fixed or Rotating Lead Stage (TSC/TSR only)
 If the display shows TSC the lead stage will not rotate. Set Point 1 will always control the Black output wires, and Set Point
2 will always control the Red output wires.
 If the display shows TSR, the lead stage will rotate every day to provide more even wear on the units being controlled; that
is, Set Point 1 will control the Black output wires one day, and the Red output wires the next day.
 If any changes were made to the operating modes, the display will flash. Then the Digi-Span will display the sensor pres-
sure.
BLACK
BLACK
24 VAC
or wire 120VAC to rear
transformer (blue wires)
SENSOR
TYPICAL WIRING DIAGRAM
HEATER
or CHILLER
OUTPUT 1
OUTPUT 1
POWER
RED
RED HEATER
or CHILLER
OUTPUT 2
OUTPUT 2
POWER
WARNING
The Digi-Span can accept only
one source of power: 120VAC
or 24VAC. If more than one
power source is applied, the
unit may be damaged.

4
COC OPERATION
Set Point 1
 Set Point 1 controls when Output 1 is energized or open as
shown in the Example.
 When Output 1 is energized, the Black output wires will be
continuous.
 When Output 1 is open, the Black output wires will be
open.
 To adjust Set Point 1, use the following steps:
1. Digi-Span should be displaying sensor pressure.
2. Press the center button and release it. The display will
change to show SP1. Wait 2 seconds or press the UP
or DOWN button and the set point will be displayed.
3. Press and hold either the UP or DOWN button until the
desired set point is displayed.
NOTE: Set Point 1 can not be set below Set Point 2. If
pressing the DOWN button does not lower Set Point 1,
it may be necessary to lower Set Point 2 (see below).
4. Wait approximately 10 seconds. If the set point was
changed, the display will flash. Then the Digi-Span will
return to displaying the sensor pressure. (If you dont
want to wait 10 seconds, press the center button once
for Set Point 2, twice for Differential, three times for
Offset or four times to display sensor pressure.)
Set Point 2
 Set Point 2 controls when Output 2 is energized or open as
shown in the Example.
 When Output 2 is energized, the Red output wires will be
continuous.
 When Output 2 is open, the Red output wires will be open.
 To adjust Set Point 2, use the following steps:
1. Digi-Span should be displaying sensor pressure.
2. Press the center button twice and release it. The
display will change to show SP2. Wait 2 seconds or
press the UP or DOWN button and the set point will be
displayed.
3. Press and hold either the UP or DOWN button until the
desired set point is displayed.
NOTE: Set Point 2 can not be set above Set Point 1. If
pressing the UP button does not increase Set Point 2, it
may be necessary to raise Set Point 1 (see above).
4. Wait approximately 10 seconds. If the set point was
changed, the display will flash. Then the Digi-Span will
return to displaying the sensor pressure. (If you dont
want to wait 10 seconds, press the center button once
for Differential, twice for Offset, or three times to display
sensor pressure.)
SET POINT and DIFFERENTIAL EXAMPL
E
Set Point 1 60psi
Set Point 2 40psi
Differential 2psi
OUTPUT 1 - BLACK
On a rise to 60psi Stage 1 will Energize
Light will Flash
--------------------------------------------------
On a drop to 58psi Stage 1 will Open
Light is OFF
OUTPUT 2 - RED
On a drop to 38psi Stage 2 will Energize
Light is ON
--------------------------------------------------
On a rise to 40psi Stage 2 will Open
Light is OFF

5
Differential
 The differential controls how many psi the system can fluctuate around the set points. It is used to prevent short cycling of
the units being controlled.
 Output 1 will energize when the sensor pressure rises to Set Point 1. Output 1 will open when the pressure falls to the Set
Point 1 minus the differential (see Example on opposite page).
 Output 2 will energize when the sensor pressure falls to Set Point 2 minus the differential. Output 2 will open when the
pressure rises to Set Point 2 (see Example opposite page).
 To set the differential, use the following steps:
1. Digi-Span should be displaying sensor pressure.
2. Press and release the center button three times. The display will change to show dIF. Wait 2 seconds or press the UP or
DOWN button and the differential will be displayed.
3. Press and hold either the UP or DOWN button until the desired differential is displayed.
4. Wait approximately 10 seconds. If the differential was changed, the display will flash. Then the Digi-Span will return to
displaying the sensor pressure. (If you dont want to wait 10 seconds, press the center button once for Offset or twice for
the sensor pressure to be displayed immediately.)
Offset
 The offset value calibrates the sensor pressure reading by the number of pounds selected.
 To adjust the offset, use the following steps:
1. The Digi-Span should be displaying sensor pressure.
2. Press the center button four times and release it. The display will change to show OFF. Wait 2 seconds or press the UP
or DOWN button and the offset will be displayed.
3. Press and hold either the UP or DOWN button until the desired offset is displayed.
4. Wait approximately 10 seconds. If the offset was changed, the display will flash and then show the corrected sensor
pressure. (If you dont want to wait, press the center button once.)
OUTPUT Light Indication
 The red OUTPUT light indicates which stage is active. When the red light is:
 OFF - Neither output stage is active. Both the Black and Red wires are open.
 FLASHING - Output 1 is energized. The Black output wires are continuous.
 ON - Output 2 is energized. The Red output wires are continuous.

6
TSC/TSR OPERATION
Set Point 1
 Set Point 1 controls when Stage 1 is energized or open as
shown in the Example.
 TSC mode - Stage 1 controls the Black output wires (see
pg. 3).
 TSR mode - For the first 12 hours of operation, Stage 1
controls the Black output wires. For the next 24 hours,
Stage 1 controls the Red output wires. Then the control
will switch back to Black and will switch again every 24
hours.
 To adjust Set Point 1, use the following steps:
1. Digi-Span should be displaying sensor pressure.
2. Press the center button and release it. The display will
change to show SP1. Wait 2 seconds or press the UP
or DOWN button and the set point will be displayed.
3. Press and hold either the UP or DOWN button until the
desired set point is displayed.
4. Wait approximately 10 seconds. If the set point was
changed, the display will flash. Then the Digi-Span will
return to displaying the sensor pressure. (If you dont
want to wait 10 seconds, press the center button once
for Set Point 2, twice for Differential, three times for
Offset or four times to display sensor pressure.)
Set Point 2
 Set Point 2 controls when Stage 2 is energized or open as
shown in the Example.
 TSC mode - Stage 2 controls the Red output wires (see pg.
3).
 TSR mode - For the first 12 hours of operation, Stage 2
controls the Red output wires. For the next 24 hours, Stage
2 controls the Black output wires. Then the control will
switch back to Red and will switch again every 24 hours.
 To adjust Set Point 2, use the following steps:
1. Digi-Span should be displaying sensor pressure.
2. Press the center button twice and release it. The
display will change to show SP2. Wait 2 seconds or
press the UP or DOWN button and the set point will be
displayed.
3. Press and hold either the UP or DOWN button until the
desired set point is displayed.
4. Wait approximately 10 seconds. If the set point was
changed, the display will flash. Then the Digi-Span will
return to displaying the sensor pressure. (If you dont
want to wait 10 seconds, press the center button once
for Differential, twice for Offset or three times to display
sensor pressure.)
NOTE: Set Point 1 does not need to be set above Set Point 2.
Either set point can be any value in the operational
range. See page 3 to set either the Heating or the
Cooling mode.
SET POINT and DIFFERENTIAL EXAMPL
E
Set Point 1 60psi
Set Point 2 50psi
Differential 2psi
HEATING MODE
On a drop to 58psi Stage 1 will Energize
Light will Flash
On a further drop to
48psi Stage 2 will Energize
Light is ON
--------------------------------------------------
On a rise to 50psi Stage 2 will Open
Light will flash
On a further rise to
60psi Stage 1 will Open
Light is OFF
COOLING MODE
On a rise to 50psi Stage 2 will Energize
Light will Flash
On a further rise to
60psi Stage 1 will Energize
Light is ON
--------------------------------------------------
On a drop to 58psi Stage 1 will Open
Light will flash
On a further drop to
48psi Stage 2 will Open
Light is OFF
TSC
Stage 1 controls Black output wires
Stage 2 controls Red output wire
TSR
Outputs rotate 12 hours after initial powerup and
every 24 hours thereafter

7
Differential
 The differential controls how many pounds the system can fluctuate around the set points. It is used to prevent short
cycling of the units being controlled.
 In the heating mode, a stage will energize when the sensor pressure falls to the set point minus the differential. The stage will
open when the pressure rises to the set point (see Example on opposite page).
 In the cooling mode, a stage will energize when the sensor pressure rises to the set point. The relay will open when the
pressure falls to the set point minus the differential.
 To set the differential, use the following steps:
1. Digi-Span should be displaying sensor pressure.
2. Press and release the center button three times. The display will change to show dIF. Wait 2 seconds or press the UP or
DOWN button and the differential will be displayed.
3. Press and hold either the UP or DOWN button until the desired differential is displayed.
4. Wait approximately 10 seconds. If the differential was changed, the display will flash. Then the Digi-Span will return to
displaying the sensor pressure. (If you dont want to wait 10 seconds, press the center button once for Offset or twice to
display sensor pressure immediately.)
Offset
 The offset value calibrates the sensor pressure reading by the number of pounds selected.
 To adjust the offset, use the following steps:
1. The Digi-Span should be displaying sensor pressure.
2. Press the center button four times and release it. The display will change to show OFF. Wait 2 seconds or press the UP
or DOWN button and the offset will be displayed.
3. Press and hold either the UP or DOWN button until the desired offset is displayed.
4. Wait approximately 10 seconds. If the offset was changed, the display will flash and then show the corrected sensor
pressure. (If you dont want to wait, press the center button once.)
OUTPUT Light Indication
 The red OUTPUT light indicates how many stages are active at any given time. When the red light is:
 OFF - Neither output stage is active. Both the Black and Red wires are open.
 FLASHING - One output stage is active. Either the Black or the Red wires are continuous, but not both.
 ON - Both output stages are active. Both the Black and Red wire are continuous.

8
TROUBLESHOOTING
No Display: Check the power to the Digi-Span. The Digi-Span can run off any of the power sources described on page 2.
Turn the power off and back on.
OPN Display: The Digi-Span does not see a sensor connected. Check the wires are continuous from the sensor to the Digi-
Span controller. Then follow the procedure for Incorrect Pressure Display.
SHT Display:The Digi-Span sees a short across the input terminals. If you remove the sensor wires from the Digi-Span
terminals, the display should change to read OPN. If the display does not change to OPN, the Digi-Span may be dam-
aged.
Incorrect Pressure Display: Remove the wires from the SENSOR screws. The display should change to read OPN. If it
doesnt, the Digi-Span may be damaged. Use a voltmeter to measure across the SENSOR screws. There should be at
least 24VDC across the two terminals. If there isnt, the Digi-Span may be damaged. Finally, reconnect the sensor with a
mA meter in series with one sensor wire. The mA reading should correspond to the chart below. You can use the Offset
value (see pg. 5 or 7) to make small adjustments to the pressure reading.
OUTPUT Red Light does not indicate desired stages are active: Check the set points and differential values. In a
heating application, the stage will not come on until the pressure drops below the set point minus the differential. In a
cooling application, the stage will come on when the pressure rises to the set point. (see Examples on pgs. 4 and 6).
Digi-Span does not activate the output: First check the OUTPUT light to see which stages should be active. If the
OUTPUT light is OFF, no stages should be running. If the OUTPUT light is flashing or on, check page 4 for a COC or
page 6 for a TSC/TSR to see which output wires should be continuous. Remove all connections to the Black and Red
output wires. Check the appropriate wires for continuity. If the wires are continuous, the Digi-Span is working properly.
Check the unit the Digi-Span is controlling to determine why it is not running.
For Technical Help or Additional Product Information contact:
Heat-Timer Corporation
20 New Dutch Lane
Fairfield, NJ 07004
Phone [phone] Fax [phone]
http://www.heat-timer.com
HT 059218-00
mA 30 PSI 100 PSI 200 PSI
4 0 0 0
4.08 1
4.16 1 2
4.4 5
4.56 1
4.8 5 10
5.06 2
5.6 3 10 20
6.13 4
6.4 15 30
6.6 5
7.2 6 20 40
8.8 930 60
10.4 12 40 80
12 15 50 100
13.6 18 60 120
15.2 21 70 140
16.8 24 80 160
18.4 27 90 180
20 30 100 200