Thermon TC 816 Operation Manual

TC 816

Operation Manual

Tracing Control Display

TCD 01

Tracing Control Display

TCD 01

Thermon Europe B.V. Tel.: [phone]
Boezemweg 25 Fax: [phone]
2641 KG Pijnacker

The Netherlands

Operation Manual 200508 E TC 816

AF TC4/5 firmware: AZ848/849 rev.2.00
TCD 01 firmware: AZ871 rev.2.43 / AZ884 rev.2.50

TC 816 Operation Manual

Table of contents

1 INTRODUCTION....................................................................................................................................................4

1.1 POSSIBLE CONTROL CONCEPTS ..........................................................................................................................4

1.1.1 Process Temperature Maintenance or Proportional Ambient Control.........................................................4

1.1.2 Frost Protection with Staged Start-Up .........................................................................................................4

1.1.3 Heat Tracing Cable Temperature Limiter ....................................................................................................4

2 THE TC 816 FOR PROCESS TEMPERATURE MAINTENANCE..................................................................5

2.1 SLOT 1: FOR AF TPA THERMON POWER SUPPLY MODULE AC...........................................................................5

2.2 SLOT 2: FOR AF TC4 OR AF TC5 TRACING CENTRAL PROCESSING MODULE.....................................................5

2.3 SLOT 3: FOR AF TIT TRACING INPUT MODULE FOR TEMPERATURE ...................................................................6

2.4 SLOT 4: FOR AF TIT TRACING INPUT MODULE FOR TEMPERATURE OR ZD TB1 BLIND PLATE...........................6

2.5 SLOT 5: FOR AF TOE TRACING OUTPUT MODULE FOR ELECTRONIC RELAYS OR AF TOM TRACING OUTPUT

MODULE FOR

2.5.1 AF TOE Tracing Output module for Electronic relays.................................................................................6

2.5.2 AF TOM Tracing Output module for Mechanical contactors.......................................................................6

2.6 SLOT 6: FOR AF TIC TRACING INPUT MODULE FOR LOAD CURRENT OR ZD TB1 BLIND PLATE .........................6

3 THE TCD 01 TRACING CONTROL DISPLAY.................................................................................................7

3.1 DESCRIPTION OF THE TCD 01 ............................................................................................................................8

3.2 START-UP OF THE TCD 01..................................................................................................................................9

3.3 CONFIGURATION OF THE TCD 01 IN GENERAL SETTINGS (SETUP) MENU ......................................................10

3.3.1 Number of First Circuit............. ........................ .................................................. ........................................11

3.3.2 Password.....................................................................................................................................................11

3.3.3 Language (1=D, 2=E, 3=F, 4=NL)............................................................................................................11

3.3.4 Selftest Cycle Time......................................................................................................................................11

3.3.5 Baudrate......................................................................................................................................................11

3.4 PASSWORD INPUT.............................................................................................................................................12

3.5 DATA COMMUNICATION BUS SEARCH .............................................................................................................13

3.6 HEAT TRACING CIRCUIT DISPLAY....................................................................................................................15

3.6.1 Heat Tracing Circuit Numbers and TC 816 Zone Numbers.......................................................................16

3.6.2 Controller and Zone Assignment

3.6.3 Column:

3.6.4 Column:

3.6.5 Column:

3.7 ACKNOWLEDGE CONTROLLER AND CURRENT ALARMS ...................................................................................20

3.8 ACKNOWLEDGE HEAT TRACING CABLE TEMPERATURE LIMITER TRIPS...........................................................21

3.9 CHANGING SET POINTS ....................................................................................................................................23

3.10 CHANGING PARAMETER VALUES .....................................................................................................................24

4 PARAMETERS......................................................................................................................................................26

4.1 ALTERING PARAMETERS ..................................................................................................................................26

4.2 ZONE PARAMETERS TO BE CONFIGURED THROUGH TCD 01 TRACING CONTROL DISPLAY ................................26

4.2.1 Parameter P01:

4.2.2 Parameter P02:

4.2.3 Parameter P03:

4.2.4 Parameter P04:

4.2.5 Parameter P05:

4.2.6 Parameter P06:

4.2.7 Parameter P07:

4.2.8 Parameter P08:

4.2.9 Parameter P09:

4.2.10 Parameter P10:

4.2.11 Parameter P11:

MECHANICAL CONTACTORS .......................................................................................................................6

MEASURED
SETPOINT
ALARM

.......................................................................................................................................18

LO-ALARM
HI-ALARM
DEV-ALARM
AL DELAY
DIGI IN
OP MODE
MAN OUTP
MAX OUTP
AV OUTP

OFFSET
COIL FACT

[C01Z01]

..............................................................................................................................17

..............................................................................................................................17

...................................................................................................................26

...................................................................................................................27

................................................................................................................27

...................................................................................................................28

.....................................................................................................................29

.....................................................................................................................30

...................................................................................................................31

...................................................................................................................32

.....................................................................................................................32

....................................................................................................................32

...........................................................................................................33

........................................................................................17

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4.2.12 Parameter P12:

4.2.13 Parameter P13: Spare........................................................... .................................................................34

4.2.14 Parameter P14: Spare........................................................... .................................................................34

4.2.15 Parameter P15: Spare........................................................... .................................................................34

4.3 ZONE PARAMETERS CONFIGURED BY HEAT TRACING SUPPLIER ........................................................................35

4.3.1 Parameter P16:

4.3.2 Parameter P17:

4.3.3 Parameter P18:

4.3.4 Parameter P19:

4.3.5 Parameter P20:

4.3.6 Parameter P21:

4.3.7 Parameter P22:

4.3.8 Parameter P23: Spare ................................................................................................................................38

4.3.9 Parameter P24:

4.3.10 Parameter P25:

4.3.11 Parameter P26:

4.3.12 Parameter P27:

4.3.13 Parameter P28:

4.3.14 Parameter P29: Spare........................................................... .................................................................42

ON DELAY

LIM ADDR
LIM ZONE
CTR MODE
P HEAT
I HEAT
D HEAT

........................................................................................................................37

........................................................................................................................37

........................................................................................................................38

APC MIN T

HYSTER

........................................................................................................................39

CYCL TIME
SENSOR #
OUTP #

....................................................................................................................41

MS MODE

..............................................................................................................33

...................................................................................................................35

...................................................................................................................35

...................................................................................................................36

................................................................................................................38

...........................................................................................................39

..............................................................................................................40

.................................................................................................................42

Operation Manual 0503 E TC 816 Page 3 of 42

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1 Introduction

The Thermon TC 816 is a multi circuit temperature controller concept developed for Electrical Heat Tracing
control. This concept allows total electrical heat tracing control configured to the needs of the customer.
The TC 816 hardware is based on electronic modules. With this approach the TC 816 can be set up for a
huge variety of control tasks required for all electric heat tracing concepts Thermon has to offer.
The TC 816 facilitates one or two data communication busses through which it can either be connected to the
Thermon TCD 01 tracing control display, a remote computer running a control and monitoring program
and/or a DCS system.
Up to 30 TC 816 temperature controllers can be interconnected through the data communication bus(ses) to
their host(s). Each communication bus has one host, being either the TCD 01 tracing control display, the
computer running the control and monitoring software and/or a DCS system.

1.1 Possible Control Concepts

The controller can be configured per controller and with process temperature maintenance per heat tracing
circuit for different control concepts. However all controller regardless of how they are configured can com­municate on one data communication bus.

This operation Manual addresses exclusively the Process Temperature Maintenance concept of the TC 816 in
conjunction with the TCD 01 tracing control display.

1.1.1 Process Temperature Maintenance or Proportional Ambient Control

• Proportional Integral Differential process temperature maintenance

• ON/OFF process temperature maintenance with configurable hysteresis in °C or °F

• Dummy Pipe or Dead Leg sensing process temperature maintenance

• Multiple Sensor MODE featuring minimum, average or maximum temperature control offering redundant

sensors in the event of a broken RTD or connection to the RTD

• Ambient Proportional Control (also suitable for frost protection)

1.1.2 Frost Protection with Staged Start-Up

• Ambient ON/OFF control with staged start up

1.1.3 Heat Tracing Cable Temperature Limiter

This control concept is required for electrical heat tracing systems in hazardous area (potentially explosive
atmospheres) which do not comply with the rated T-class.
The heating cables sheath temperature is sensed, when the sheath temperature exceeds the controller’s tem­perature set point the controller switches the heat tracing off and generates a high temperature alarm. The
heat tracing can only be switched back on manually if the high temperature condition has recovered.

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2 The TC 816 for Process Temperature Maintenance

The enclosure of the TC 816 is constructed to be mounted on the back plane of a panel. The enclosure facili­tates 6 slots for electronic modules, each having its particular task.

Below the slots and the possible modules are described from the most right position to the left:

2.1 Slot 1: For AF TPA Thermon Power supply module AC

The AF TPA module is a multi voltage switching power supply suitable for voltages between 85 and 265 Vac
50/60 Hz.

This module also facilitates voltage free alarm contacts for:

• HI-Alarm: - high temperature

- high current (only if AF TIC module is applied in slot 6)

- open or short circuited RTD sensor

• LO-Alarm: - low temperature

- low current (only if AF TIC module is applied in slot 6)

• DEV-Alarm: - too much deviation from temperature set point

- too much deviation from load current set point (only if AF TIC module is applied in slot 6)

• System-Al.: Hardware controlled self check

2.2 Slot 2: For AF TC4 or AF TC5 Tracing Central processing module

The AF TC4 or AF TC5 can be inserted into slot 2 as central processing module. The central processing mod­ule is the intelligence of the TC 816. It allows the controller independent operation. This means, that the TC
816 can operate even if the communication bus is disconnected.
The non volatile memory of the AF TC4 and AF TC5 modules enables fast and safe start-up and recovery after
eventual power failures. The last set parameter values are still stored in the memory.
The AF TC4 central processing module facilitates a 24 Vdc digital input and 2 separate RS 485 communication
busses (utilising galvanic separation).
The AF TC5 central processing module facilitates a 24 Vdc digital input, a RS 485 communication bus and
independent standard Profibus connection (both interfaces utilising galvanic separation).

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2.3 Slot 3: For AF TIT Tracing Input module for Temperature

The AF TIT is an 8 circuit, 4 wire, RTD PT 100 temperature input module. By bridging the compensation ter­minals this module is also suitable foe 3 wire and 2 wire RTD PT 100 sensors.

2.4 Slot 4: For AF TIT Tracing Input module for Temperature or ZD TB1 blind

plate

Whether slot 4 is equipped with an AF TIT module or with a ZD TB1 blind plate determines whether the TC
816 is set up for 16 or 8 heat tracing circuits.

2.5 Slot 5: For AF TOE Tracing Output module for Electronic relays or AF TOM

Tracing Output module for Mechanical contactors

2.5.1 AF TOE Tracing Output module for Electronic relays

The AF TOE utilises 2 terminals for external 24 Vdc power supply in order to provide enough capacity to drive
up to 16 solid state relays or small 24Vdc driven mechanical contactors.

In general this module is applied if PID process temperature maintenance control (also for dummy pipe or
dead leg sensing) or ambient proportional control is required. Solid state relays are the best solutions for
those control concepts because they do not wear out considering the amount of switch actions they have to
fulfil.

The advantage is, that off the shelf Solid State relays can be connected to the TC 816 so switching capacity of
a TC 816 system is only limited by the panel construction parameters like feeding power, cooling capacity in
the panel.

Additional this module offers the unique possibility of digital inputs (24Vdc) enabling to:

• monitor status of 16 individual MCB/RCD units through the MDB/RCD’s auxiliary contact(s)

• monitor for instance signals from DCS or switches in order to set Parameter P06

able Zone operation” (see chapter 4.2.6). This can for used to for instance for maintenance purposes.

Only the AF TOE module offers this feature.

OP MODE to “dis-

2.5.2 AF TOM Tracing Output module for Mechanical contactors

The AF TOM utilises 16 voltage free contactors capable of driving up to 250 Vac mechanical contactor coils.

2.6 Slot 6: For AF TIC Tracing Input module for load Current or ZD TB1 blind

plate

Whether slot 6 is equipped with an AF TIC module or with a ZD TB1 blind plate determines whether the TC
816 is set up for current load monitoring or not.

The AF TIC tracing Input module for load current facilitates 16 current transformer inputs. To those inputs the
AT T4I DIN rail mounted 4 circuit current transformer module has to be connected. One AT T4I module facili­tates current monitoring for 4 circuits. In order to fully equip the AF TIC 4 AT T4I modules are needed, this
provides current monitoring for 16 circuits.

In addition the AF TIC utilizes a voltage compensation input. To this input either a fixed resistor (default factory
delivery) or AT TU1 DIN rail mounted voltage compensation module can be connected. This option enables
automatic current set point shifting to avoid current deviation alarms in case of supply voltage variations,
which can be common in industrial environment. This option should only be applied with constant watt heat
tracing cables.

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3 The TCD 01 Tracing Control Display

The TCD 01 tracing control display allows the operator to have full control over the heat tracing circuits which
are controlled by the connected TC 816 temperature controllers.

The TCD 01 is the host on the RS 485 data communication bus. It searches on the communication bus for TC
816 heat tracing temperature controllers which need to have their own unique communication address (to be
set by DIP switches on the AF TC4 tracing central processing module).

The TCD 01 tracing control display shall be powered by an external 24 Vdc power supply. That supply can be
the same providing the 24 Vdc power to drive the solid state relays or mechanical contactors in the panel.

Two versions of the TCD 01 are available.

• A TCD 01 for single phase current display per tracing circuit (firmware AZ 871)

• A TCD 01 for three phase current display per tracing circuit (firmware AZ 884)

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3.1 Description of the TCD 01

Tracing Control Display

Figure 4.1 TCD 01 Tracing Control Display

Description of buttons and indication lights:

, Down Button:

Allows you to scroll down particular set points, parameter numbers etc. as shown in the display above the
applicable down button.
Pressing this button for a short time decreases by single steps, holding it will accelerate the scroll.

, Up Button:

Allows you to scroll up particular set points, parameter numbers etc. as shown in the display above the appli­cable down button.
Pressing this button for a short time decreases by single steps, holding it will accelerate the scroll.

TCD 01

, Enter Button:

Is generally used to enter or save settings. However, sometimes can have a different function as shown in the
display above this particular button.

, Acknowledge Button:

Is generally used to acknowledge alarms. After acknowledging alarms of one heat tracing circuit the TCD 01
tracing control display will automatically show the next circuit with alarm conditions to be acknowledged.

, Tracing Alarm Light:

Illuminates when an un-acknowledged Alarm condition is detected in a controller connected to the data
communication bus. The TCD 01 tracing control display will automatically show the circuit with alarm condi­tions to be acknowledged.

, TCD 01 System Alarm Light:

Illuminates when the hardware controlled self check detects a program stop in the TCD 01 tracing control
display

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3.2 Start-up of the TCD 01

After:

• having setup the hardware wiring of the RS 485 data communication bus

• setting the communication address of the connected TC 816 controllers

• and applying the 24 Vdc power supply

The TCD 01 tracing control display illuminates yellow and looks as below:

Figure 4.2 TCD 01 Tracing Control Display: Start-Up (Version and date might differ from illustra-

tion)

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3.3 Configuration of the TCD 01 in General Settings (SETUP) Menu

By pressing the and buttons below SETUP simultaneously you can enter the General Settings
menu.

At any time in any display the General Settings Menu can be entered by pressing the same buttons simulta­neously.

The General Settings menu can be left without saving changes by pressing the

EXIT simultaneously. If you want to save changes and leave this menu press the button below SAVE

and buttons below

or press the
the communication bus.

By pressing the or buttons below SELECTION you can select the appropriate parameter to be
changed.

By pressing the

button. Pressing the button will additionally cause a restart of the TCD 01 and rescan of

Figure 4.3 TCD 01 Tracing Control Display: General Settings Menu

or buttons below SETPOINT you can change the values of the parameters.

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Figure 4.3 TCD 01 Tracing Control Display: General Settings Menu

In the General Setting Menu following parameters can be set:

3.3.1 Number of First Circuit

This number determines the first visual circuit number to be shown in the display. This feature is very handy
in case multiple heat tracing control panels are required in one plant. It enables unique heat tracing circuit
numbers throughout the plant.

3.3.2 Password

Here a security password, a 3 digit number can be set for parameter and General Settings Menu protection.
For changing temperature or load current set point no password is needed. Do never forget the password
number. Note it down where only authorised personnel can find it.

000: means no password protection of parameters

NOTE: The password must always be set in case a TC 816 configured as Heat Tracing Cable Temperature

Limiter is connected to the TCD 01. It ensures that all trips of that safety device can only be acknowl­edged through a password, as required for temperature protection devices in hazardous areas
(potentially explosive atmospheres)

3.3.3 Language (1=D, 2=E, 3=F, 4=NL)

With this parameter the TCD 01 text language can be changed between German (D for “Deutsch”) and Eng­lish.

001: Deutsch (German)
002: English, Default
003: Francaise (French)
004: NederLands (Dutch)

3.3.4 Selftest Cycle Time

This parameter determines the period in hours after which the TCD 01 prompts the connected TC 816 con­trollers to check the alarm status again.

3.3.5 Baudrate

With this parameter, the Baud rate can be selected. The options are 9.600 Baud and 19.200 Baud. The
19200 Baud must be used when using eg MODbus communication

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Password Input

When in the General Settings Menu a password is set to other than 000 (see chapter 3.3.2), the following
display will prompt you to enter the password whenever you try to change a set point. The password has not

to be re entered as long as the two brackets are shown around a set point in the display or you are still in a
parameter menu (see chapter 3.7 and 3.10).

Tracing Control Display

Figure 4.4 TCD 01 Tracing Control Display: Password Input

You can change the value of the password field by pressing the or buttons below PASSWORD to
the password which was set in the General Settings Menu.

The password value is entered with the
to the desired Parameter display or to the General Settings Menu.

ENTER button . If the password is correct the TCD 01 continues

TCD 01

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3.5 Data Communication Bus Search

After the Start-Up screen is left automatically or the General Settings Menu has been left by pushing the ac­knowledge button, the TCD 01 starts searching the RS 485 communication bus for connected TC 816 heat
tracing temperature controllers.

Tracing Control Display

TCD 01

Figure 4.5 TCD 01 Tracing Control Display: Data Communication Bus Search

As shown in figure 4.5 a RS 485 data communication bus with up to 30 controllers can be hosted by the TCD

01. Therefore up to 480 (16 x 30) heat tracing circuits can be connected to one TCD 01 tracing control dis­play.

Every controller is listed by its set communication address. When a controller is detected it is automatically
checked for what kind of control concept the controller is configured and for how many circuits.

The display shows next to the 30 possible communication addresses:

?: No controller assigned

•

CONT: Controller configured for Process Temperature Maintenance or Proportional Ambient Control

•

(see chapter 1.1.1)

FPSS: Controller configured for Frost Protection with Staged Start-Up (see chapter 1.1.2)

•

LIM: Controller configured for Heat Tracing Cable Temperature Limiter (see chapter 1.1.3)

•

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After the data communication bus search is completed choices are offered to the user how to deal with the
result of the bus search, see figure 4.6.

Tracing Control Display

Figure 4.6 TCD 01 Tracing Control Display: Bus Configuration

• RESCAN: In case not all expected controllers are show the missing controller can be

(re)connected to the bus system or faulty communication address settings corrected
and the bus can be re-scanned. Press the

CONFIRM: Accept/confirm the bus configuration by pressing the or buttons below

•

CONFIRM
SKIP: In the event a controller is disconnected from the bus system, but the circuit

•

numbers in the TCD 01 Tracing Control Display have to remain as before the
controller was disconnected press the

displayed result of the bus scan and operate the TCD 01 with the original circuit
numbers.

After choosing

CONFIRM or SKIP the TCD 01 automatically switches to heat tracing circuit display.

.

or buttons below RESCAN.

or buttons below SKIP to ignore the

TCD 01

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3.6 Heat Tracing Circuit Display

After the Data Communication Bus Search has been completed the TCD 01 tracing control display shows the
following.

Two versions of the TCD 01 are available.

• A TCD 01 for single phase current display per tracing circuit, with firmware AZ 871, see figure 4.7

• A TCD 01 for three phase current display per tracing circuit, with firmware AZ 884, see figure 4.8

Tracing Control Display

TCD 01

Figure 4.7 TCD 01 Tracing Control Display: Heat Tracing Circuit Display for single phase cur-

rent display

Tracing Control Display

TCD 01

Figure 4.8 TCD 01 Tracing Control Display: Heat Tracing Circuit Display for three phase current

display

By pressing the

or buttons below CIRCUIT you can scroll through the heat tracing circuits.

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Description:

3.6.1 Heat Tracing Circuit Numbers and TC 816 Zone Numbers

In order to properly configure the TC 816 it is very important to know the difference between heat tracing
circuit numbers and TC 816 Zone numbers. In this manual referred to as circuit numbers and zone numbers.

Zone Numbers:

Each TC 816 could count up to 32 analogue inputs depending on its configuration. Each analogue input is
called a Zone. With the TC 816 there is a clear distinction between temperature input Zones and current input
zones. The type of Zone can easily be recognised by their number:

• Zone 1 through 16: Temperature input Zones (2 x AF TIT, each 8 Zones)

• Zone 17 through 32: Load current input Zones (1 x AF TIC, 16 Zones)

For each particular Zone, 29 so called Zone parameters can be set.

Circuit Numbers:

Multiple Zone numbers of particular TC 816 controllers can be assigned to one Heat Tracing Circuit Number.
For instance, the in Figure 4.6 displayed Circuit 001 could include analogue inputs (Zones) for:

• A pipe temperature control (

Zone 1 of TC 816 controller with communication address 1.

• A temperature sensor for heat tracing cable temperature limitation (

Zone 1 of TC 816 controller (configured for Heat Tracing Cable Temperature Limiter concept) with
communication address 2.

• A load current input for heat tracing circuit load current monitoring (

Zone 17 of TC 816 controller with communication address 1.
The TC 816 automatically assigns Zone 17 to Zone 1 of the same controller if at start-up an AF TIC Tracing
Input module for load Current is detected.

CONTROLLER-line), using:

LIMITER-line), using:

CURRENT-line) , using:

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3.6.2 Controller and Zone Assignment [C01Z01]

The indication [C01Z01] behind the circuit number in the top line of the display is:

C01: the assigned TC 816 communication address

•

Z01: the assigned controller Zone number of the applicable TC 816 controller. With CURRENT

•

values and
only the

This indication gives a clear reference for the operator in case of alarm which controller and panel to check
out.

LIMITER values some analogue inputs are linked together as one circuit,

CONTROLLER Zone number is mentioned.

3.6.3 Column: MEASURED

This column shows:

• In the

• In the

• In the

CONTROLLER-line: Measured pipe temperature

- Applicable for controller-Zones 1 through 16

- Units:
°C or °F (depending on DIP-switch setting for temperature units)

LIMITER-line: Measured heat tracing cable temperature

- Only applicable if a limiter-Zone (from a separate TC 816
controller) is assigned to this particular heat tracing circuit, by
parameters P16 and P17 of the controller Zone.

- Units:
°C or °F (depending on DIP-switch setting for temperature units)

CURRENT-line(s): Measured load current(s)

- Only applicable if AF TIC Tracing Input module for load Current is
installed, controller-Zone 17 through 32

- Unit: A

3.6.4 Column: SETPOINT

This column shows:

• In the

• In the

• In the

CONTROLLER-line: Set point for pipe temperature

LIMITER-line: Set point for maximum heat tracing cable sheath temperature

CURRENT-line(s): Set point for load current

- Applicable for controller-Zones 1 through 16

- Units:
°C or °F (depending on DIP-switch setting for temperature units)

- Only applicable if a limiter-Zone (from a separate TC 816
controller) is assigned to this particular heat tracing circuit, by
parameters P16 and P17 of the controller Zone.

- Units:
°C or °F (depending on DIP-switch setting for temperature units)

- This set point is for load current DEV-ALARM (deviation alarm)
reference only, the TCD 01 heat tracing temperature
controller does not control the load current, it does monitor it.

- Only applicable if AF TIC Tracing Input module for load Current is
installed, controller-Zone 17 through 32

- Unit: A

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3.6.5 Column: ALARM

This column shows:

• In the

• In the

CONTROLLER- line (controller-Zones 1 through 16):

-OK.-: No alarm condition

-L-: Low temperature alarm condition

Measured temperature dropped below the LO-ALARM set point (parameter P01)

-H-: High temperature alarm condition

Measured temperature exceeded the HI-ALARM set point (parameter P02)

-DEV-: DEViation temperature alarm condition

Trips in case of:

- Measured temperature dropped below the value:

controller temperature set point - DEV-ALARM set point (parameter P03)

- Measured temperature exceeded the value:

controller temperature set point + DEV-ALARM set point (parameter P03)

-I-: Load current alarm condition

Trips in case of:

- The MCB/RCD AL auxiliary contacts are wired to the digital inputs of the AF TOE

Tracing Output module for Electronic relays and parameter P05 enables MCB/RCD

monitoring.

- The AF TIC Tracing Input module for load Current is installed and a alarm condition

in the

CURRENT-line of the TCD 01 display occurs.

-E-: Sensor alarm condition

Trips in case of:

- Short circuited RTD input on AF TIT Tracing Input module for Temperature

- Open RTD input on AF TIT Tracing Input module for Temperature

-com-: Communication alarm condition

The TCD 01 tracing control display can not access the measure controller

value or set point through the RS 485 data communication bus.

-OFF-: Alarm condition monitoring disabled

This situation occurs if the heat tracing circuit is set to manual or OFF

(parameter P06)

LIMITER-line (limiter-Zones 1 through 16):

-OK.-: No alarm condition

-H-: High temperature alarm condition

Measured temperature exceeded the limiter set point

-com-: Communication alarm condition

The TCD 01 tracing control display can not access the measure controller

value or set point through the RS 485 data communication bus.

-OFF-: Alarm condition monitoring disabled

This situation occurs if the heat tracing circuit is set to manual or OFF

(parameter P06)

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• In the

CURRENT-line (controller-Zones 17 through 32):

-OK.-: No alarm condition

-L-: Low current alarm condition

Measured current dropped below the LO-ALARM set point (parameter P01)

-H-: High current alarm condition

Measured current exceeded the HI-ALARM set point (parameter P02)

-DEV-: DEViation current alarm condition

Trips in case of:

- Measured current dropped below the value:

controller current set point - DEV-ALARM set point (parameter P03)

- Measured current exceeded the value:

controller current set point + DEV-ALARM set point (parameter P03)

-com-: Communication alarm condition

The TCD 01 tracing control display can not access the measure controller

value or set point through the RS 485 data communication bus.

-OFF-: Alarm condition monitoring disabled

This situation occurs if the heat tracing circuit is set to manual or OFF

(parameter P06)

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3.7 Acknowledge Controller and Current Alarms

In case an alarm occurs, the TCD 01 Tracing Control Display will automatically show the heat tracing circuit
where the latest alarm occurred. In the

is displayed and an message appears in the top right corner

• TCD 01 for single phase current display per tracing circuit, with firmware AZ 871, will in addition give a

beep as audible alarm.

• TCD 01 for three phase current display per tracing circuit, with firmware AZ 884, will not sound an audi-

ble alarm.
Also the applicable hardware alarm contacts of the AF TPA Thermon Power supply module AC trip (see TC
816 Hardware Configuration Guide).

CONTROLLER- or CURRENT- lines the applicable alarm code

PRESS (Q) TO ACK.

Tracing Control Display

Figure 4.9 TCD 01 Tracing Control Display: Heat Tracing Circuit Display with low temperature

alarm trip, as example

Acknowledge the alarm as follows:

1. Press the

button.

2. The TCD 01 will display either:
a. Remain in the same circuit showing

the display, see figure below.

or

b. Jump to another circuit which is an un-acknowledged alarm status.

TCD 01

--ACKNOWLEDGED-- in the top right corner of

Tracing Control Display

Figure 4.10 TCD 01 Tracing Control Display: Heat Tracing Circuit Display with low temperature

alarm trip, as example

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TCD 01

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3. Should the TCD 01 not jump to display the status of another circuit and the alarm statuswill disap-

pear:

--ACKNOWLEDGED—will disappear fron the top left corner in the display

a.

and

b. alarm status

-L- (example) will change into OK,

3.8 Acknowledge Heat Tracing Cable Temperature Limiter Trips

For a description of a Heat Tracing Cable Temperature Limiter see chapter 1.1.3. In case a TC 816 configured
as Heat Tracing Cable Temperature Limiter is connected to the TCD 01 Tracing Control Display, the TCD 01
displays a value for

Should the sensed heating cable sheath temperature raise above the
ture alarm, The TCD 01 Tracing Control Display will automatically show the heat tracing circuit where the Heat

Tracing Cable Temperature Limiter tripped. In the
an message appears in the top right corner

• TCD 01 for single phase current display per tracing circuit, with firmware AZ 871, will in addition give a

beep as audible alarm.

• TCD 01 for three phase current display per tracing circuit, with firmware AZ 884, will not sound an audi-

ble alarm.
Also the hardware high alarm contacts of the AF TPA Thermon Power supply module AC will trip (see TC 816
Hardware Configuration Guide).

MEASURED , SETPOINT and status of ALARM In the LIMITER-line.

LIMITER-set point a high tempera-

LIMITER-line the -H- alarm code is displayed and

PRESS (Q) TO ACK.

Tracing Control Display

Figure 4.11 TCD 01 Tracing Control Display: Displaying a Heat Tracing Cable Temperature Lim-

iter trip

Acknowledge the Heat Tracing Cable Temperature Limiter trip as follows:

1. Press the

2. The password protection of the TCD 01 Tracing Control Display has to be activated, in case a Heat

Tracing Cable Temperature Limiter is connected to the TCD 01, see note in chapter 3.3.2, Therefore
the TCD 01 will prompt for a password. See chapter 3.4 for how to input the password.

3. After the password has been entered successful, the TCD will display either:
a. Remains in the same circuit showing

or

b. Jump to another circuit which is an un-acknowledged alarm status.

button.

--ACKNOWLEDGED-- in the top right corner

of the display, see figure below.

TCD 01

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Tracing Control Display

Figure 4.12 TCD 01 Tracing Control Display: Displaying an acknowledged Heat Tracing Cable

Temperature Limiter trip

4. Should the TCD 01 not jump to display the status of another circuit and the alarm statuswill disap-

pear:

--ACKNOWLEDGED—will disappear fron the top left corner in the display

a.

and

b. alarm status

NOTE: Heat Tracing Cable Temperature Limiter will NOT switch the heat tracing back on unless the trip has

been acknowledged the alarm status

-H- will change into OK,

-H- has disappeared.

TCD 01

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3.9 Changing Set Points

From Heat Tracing Circuit Display the set points can be changed as follows:

1. Hold down the

2. In case a password protection has been activated, the TCD 01 will prompt for a password (see chap-

ter 3.4)

3. Brackets around the set point in the

button below SELECTION for about 5 seconds.

CONTROLLER- line appear see below:

Tracing Control Display

TCD 01

Figure 4.13 TCD 01 Tracing Control Display: Heat Tracing Circuit Display ready for changing set

points, illustrated with a three phase TCD 01

4. Select with the or buttons below SELECTION which set point you wish to change.

5. Change the set point to the required value by using the

6. Confirm and store the set point with the

ENTER button .

or buttons below SETPOINT.

7. The brackets around the set point will disappear automatically after about half a minute, if no buttons

have been pressed.

NOTE: Zones are not supervised when their set point is set to 0.

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3.10 Changing Parameter Values

From Heat Tracing Circuit Display the set points can be changed as follows:

1. Hold down the

2. Brackets around the set point in the

button below SELECTION for about 5 seconds.

CONTROLLER- line appear, see below:

Tracing Control Display

Figure 4.14 TCD 01 Tracing Control Display: Heat Tracing Circuit Display ready for changing set

points, illustrated with a single phase TCD 01

3. Select with the or buttons below SELECTION which parameter in which parameter set

you wish to change:

- In the

- In the

- In the

4. Hold down the

seconds.

5. The parameter configuration display appears, see below:

CONTROLLER-line: Controller Zones 1 to 16
LIMITER-line: Limiter Zones 1 to 16
CURRENT-line: (Load current) Zones 17 to 32

ENTER button while pressing the button below CIRCUIT for about 5

TCD 01

Tracing Control Display

Figure 4.15 TCD 01 Tracing Control Display: Parameter P01 configuration display

6. By pressing the or buttons below CIRCUIT you can select the appropriate parameter to

be changed. Notice the change of Circuit number in the top line.

7. By pressing the

to be changed. Notice the change of parameter description in the top line.

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TCD 01

or buttons below SELECTION you can select the appropriate parameter

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8. Change the set point to the required value by using the

9. Confirm and store the set point with the

ENTER button .

or buttons below SETPOINT.

10. After configuring the relevant parameters exit the parameter configuration display by holding down

ENTER button while pressing the button below CIRCUIT for about 5 seconds.

the

NOTE: Parameter numbers from P16 through P29 can only be viewed with the TCD 01 tracing control dis-

play. Those parameters can only be changed with the Paracon or Visual Fecon software through a PC
connected to one of the data communication busses.

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4 Parameters

4.1 Altering Parameters

Each Zone (for description see chapter 3.6.1) can be configured with up to 29 so called Zone-parameters in
order to assign functionality as required by the end user.

The parameters are numbered with a capital P followed by 2 digits and have particular names in case they are
not spare parameters for future use.

Parameters P01 through P15 could be altered by the end user operating through the TCD 01 tracing control
display (see chapter 3.10). However the Parameters P01 through P15 can be password protected in order to
avoid unauthorised access (see chapter 3.3.2).

Parameters P16 through P29 are pre configured by the heat tracing supplier, they should not be altered dur­ing operation at all. Only in case a heat tracing circuit has been physically changed, changes should be made
by responsible (heat tracing design) engineer.

Changing Parameters P16 through P29 is possible by:

1. Set DIP 2 of 5 pole DIP switch of AF TC1/4/5 to ON-position (see TC 816 Hardware Configuration

Guide).

2. Use one of the following tools to alter Parameters P16 through P29:

- TCD 01 (single phase current display) with firmware AZ871 rev.2.41 or higher

- TCD 01 (three phase current display) with firmware AZ884 rev.2.32 or higher

- Paracon software running on a PC through converter USB or RS232 to RS285

- Visual Fecon monitoring software running on a PC through converter USB or RS232 to RS285

4.2 Zone Parameters to be configured through TCD 01 tracing control display

4.2.1 Parameter P01: LO-ALARM

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: °C or °F

• Not valid for Limiter Zones

• Valid for Current Zones

- Zones 17 through 32

- unit in: 0,1 x A => value of 10 means 1 A

Measurement below the value set for parameter P01 triggers the respective zone
in:

• tripping the appropriate Lo-alarm contact on the AF TPA Thermon Power supply module AC

• the Lo-LED on the AF TPA module lights up red

Adjustment thresholds: 0...630
Default value: 0

NOTE:

LO-ALARM is not supervised when the reference set point in the circuit display is set to “0” or

operation mode (P06:

OP MODE) is set to OFF.

LO-ALARM, this results

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4.2.2 Parameter P02: HI-ALARM

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: °C or °F

• Not valid for Limiter Zones

• Valid for Current Zones

- Zones 17 through 32

- unit in: 0,1 x A => value of 10 means 1 A

Measurement above the value set for parameter P02 triggers the respective zone
in:

• tripping the appropriate Hi-alarm contact on the AF TPA Thermon Power supply module AC

• the green Hi-LED on the AF TPA module extinguishes

Adjustment thresholds: 0...630
Default value: 630

NOTE:

HI-ALARM is not supervised when the reference set point in the circuit display is set to 0.

But

HI-ALARM is supervised when operation mode (P06: OP MODE) is set to OFF. The rea-

son for this practice is that a faulty actuator (for instance short circuited) which is connected to the
output modules will cause high alarm and thus be detected.

HI-ALARM, this results

4.2.3 Parameter P03: DEV-ALARM

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: °C or °F

• Not valid for Limiter Zones

• Valid for Current Zones

- Zones 17 through 32

- unit in: 0,1 x A => value of 10 means 1 A

As soon as the actual value of a zone deviates from the reference set point in the circuit display by more than
the value set for P03 the respective zone

• tripping the appropriate Dev-alarm contact on the AF TPA Thermon Power supply module AC

• the Lo-LED on the AF TPA module lights up red

Adjustment thresholds: 1...630
Default value: 15

NOTE:

DEV-ALARM is not supervised when the reference set point in the circuit display is set to “0” or op-

eration mode (P06:

OP MODE) is set to OFF.

DEV-ALARM is triggered, this results in:

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4.2.4 Parameter P04: AL DELAY

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: s (seconds)

• Not valid for Limiter Zones

• Valid for Current Zones

- Zones 17 through 32

- unit in: s (seconds)

With parameter P04 you can set the alarm delay (
moment of faulty condition and the actual alarm trips.

This function is useful in order to avoid alarm trips in case for instance the equipment, traced with a suitable
high temperature heating cable is steamed out.

Adjustment thresholds: 0...999
Default value: 0

AL DELAY) in seconds. This is the time between the

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4.2.5 Parameter P05: DIGI IN

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: not applicable

• Valid for Limiter Zones

- Zones 1 through 16, possibly of different TC 816 unit on same data communication bus

- unit in: not applicable

• Not valid for Current Zones

With Parameter P05 you can program the function of the digital inputs of AF TOE Tracing Output module for
Electronic relays.

There are a couple of functions for which each digital input can be programmed:

MCB/RCD status monitoring:
Is very comfortable since the TCD 01 tracing control display or the optional control and monitoring software
can tell exactly which MCB and/or RCD has tripped, avoiding searches having to open miscellaneous panels.
The right panel door can be addressed immediately by checking the circuit number in the panel drawings.

In case the TC 816 controller is not configured for load current monitoring with an AF TIC Tracing Input mod­ule for load Current, the MCB/RCD status monitoring allows you to distinguish between:

• An open circuit situation: low temperature trip but no current alarm

• MCB or RCD trip: current alarm

Without the MCB/RCD status monitoring just a low temperature alarm would occur in that case, because
without power the heat tracing does not heat.

Disable MCB/RCD status monitoring in case:

• the AF TOM Tracing Output module for Mechanical contactors which offers no MCB/RCD status moni-

toring input is available in slot 5 of the TC 816

• no MCB/RCD’s auxiliary contacts are connected to the applicable digital input (numbered by the control-

lers/limiters temperature Zones 1 through 16)

Enable MCB/RCD status monitoring in case:

• the AF TOE Tracing Output module for Electronic relays which offers MCB/RCD status monitoring input.

• MCB/RCD’s auxiliary contacts of active heat tracing circuits are connected to the applicable digital input

(numbered by the controllers/limiters temperature Zones 1 through 16)

Operation mode input:
This function is comfortable in case the OP MODE of the tracing circuits shall be switched to “Disable Zone

operation” (see chapter 4.2.6) for maintenance purposes by means of a maintenance switch. Or the circuit
shall be disabled by an external instrument because no heat tracing is required under certain conditions. For
example a flow meter disabling the heat tracing in case flow in the traced pipe is detected.

Adjustment thresholds: 0 = Disable digital input monitoring

3 = For Zones 9 through 16 only!

Default value: 0

1 = Enable MCB/RCD status monitoring (MCB/RCD alarm with 24Vdc on digital
input)
2 = Enable operation mode input (Circuit disabled with 24Vdc on digital input)

Enable operation mode input next to MCB/RCD status monitoring for Zones
1 through 8, same succession (Circuit disabled with 24Vdc on digital input)

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4.2.6 Parameter P06: OP MODE

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: not applicable

• Valid for Limiter Zones

- Zones 1 through 16, possibly of different TC 816 unit on same data communication bus

- unit in: not applicable

• Valid for Current Zones

- Zones 17 through 32

- unit in: not applicable

Parameter P06 allows the maintenance team of the end user to change the operation mode per Zone.

OP MODE to “disable Zone operation” in case:

Set

• An alarm occurred and the heat tracing circuit under maintenance and the MCB is switched off. This

avoids current or low temperature alarms, during maintenance of that particular circuit.

OP MODE to “manual operation” in case:

Set

• A sensor alarm occurred, but the heat tracing should continue to heat, while the sensor is being discon-

nected for replacement.

• Manual operation is required in order to check actuator operation.

OP MODE to “automatic operation” in case:

Set

• Automatic temperature is required (normal operation mode)

Adjustment thresholds: 0 = Disable Zone operation

1 = Manual operation, the TC 816 gives the power output set in
parameter P07

2 = Automatic operation

Default value: 2

Note: During operation mode “0” (disabled Zone operation) the high alarm supervision of the applicable

Zone will remain enabled, unless the reference set point in the circuit display is set to 0.
Operation mode “1” (manual operation) is not applicable for current Zones 17 through 32.

MAN OUTP

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4.2.7 Parameter P07: MAN OUTP

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: %

• Not valid for Limiter Zones

• Not valid for Current Zones

Set point

MAN OUTP of parameter P07 determines the power output in % in case Parameter P06: OP

MODE is set to “1” (manual operation). See chapter 4.2.6.

The TC 816 regulates power output by switching ON and OFF (cycling) the supply voltage within a certain
cycle time (parameter P25

In order to choose the best set point you could consult parameter P09
the average power output in % of full scale over the past period of automatic operation.

Adjustment thresholds: 0...100
Default value: 0

CYCL TIME).

AV OUTP. This parameter gives

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4.2.8 Parameter P08: MAX OUTP

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: %

• Not valid for Limiter Zones

• Not valid for Current Zones

Set point
tracing circuit, in case the control mode P18
will not allow more power than this percentage of the full scale.

The full scale power output is what the heat tracing circuit would dissipate in case the supply voltage would
not be cycled, thus stay ON all time.

Adjustment thresholds: 0...100
Default value: 100

4.2.9 Parameter P09: AV OUTP

This Parameter is:

• Valid for Temperature Controller Zones

• Not valid for Limiter Zones

• Not valid for Current Zones

Parameter P09 can not be set, only monitored. This parameter gives the average power output (AV OUTP)
in % of full scale over the past period of automatic operation.

Range: 0...100
Default value: not applicable

MAX OUTP of parameter P08 determines the maximum controller power output for the heat

CTRL MODE is set to PID control. In no case the controller

- Zones 1 through 16

- unit in: %

4.2.10 Parameter P10: OFFSET

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: °C or °F

• Valid for Limiter Zones

- Zones 1 through 16

- unit in: °C or °F

• Valid for Current Zones

- Zones 17 through 32

- unit in: 0,1 x A => value of 10 means 1 A

Parameter P10 allows field tuning of temperature and current by adjusting the

Range: -50...+50
Default value: 0

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4.2.11 Parameter P11: COIL FACT

This Parameter is:

• Not valid for Temperature Controller Zones

• Not valid for Limiter Zones

• Valid for Current Zones

- Zones 17 through 32

- unit in: amount of passes

The AT T4I current transformer module has an operating range of 2 through 100 A. In case it is expected that
the heat tracing circuit operation load current is below 2 A the phase conductor to the heat tracing circuit

should be passed through the current transformer multiple times. The amount of passes (
the result of 2 A divided by the expected operation load current in A.

Range: 1...10
Default value: 0

COIL FACT) is

4.2.12 Parameter P12: ON DELAY

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: s (seconds)

• Not valid for Limiter Zones

• Not valid for Current Zones

In case the TC 816 is configured for:

• Frost Protection with Staged Start-Up control concept (default parameter P12 setting)

• Parameter P18 (

the heat tracing circuits can be configured with a start-up delay time.

With frost protection with Staged Start-Up control concept all heat tracing would be switched on at the same
moment in case the ambient sensing thermostat would give the signal. In that case too much inrush current
(normal phenomena with self regulating heating cables) at the same time should be avoided. The main circuit
breaker of the panel could trip. This can be solved by setting

to generate staged start-up.

With process temperature ON/OFF control, most heat tracing circuits switch randomly ON/OFF. In this case it
is more convenient to set parameter P12 to “0”.

Range: 0...999
Default value: Zone number x 30 s => For Zone 3: 3 x 30 s = 90 s

CTR MODE) is set to ON/OFF control

ON DELAY times in parameter P12 in order

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4.2.13 Parameter P13: Spare

This Parameter has no function, it is a spare parameter to give the possibility of future functional expansion of
the TC 816 heat tracing temperature controller.

4.2.14 Parameter P14: Spare

This Parameter has no function, it is a spare parameter to give the possibility of future functional expansion of
the TC 816 heat tracing temperature controller.

4.2.15 Parameter P15: Spare

This Parameter has no function, it is a spare parameter to give the possibility of future functional expansion of
the TC 816 heat tracing temperature controller.

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4.3 Zone Parameters configured by heat tracing supplier

4.3.1 Parameter P16: LIM ADDR

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: TC 816 communication address

• Not valid for Limiter Zones

• Not valid for Current Zones

To each temperature controller Zone a heat tracing cable temperature limiter Zone can be assigned. Accord­ing to the EN 50 014 standard for electrical equipment in hazardous area the limiter Zone needs to be utilised
by a separate electronic controller. Within the TC 816 multi circuit temperature controller concept that can be
any other TC 816 controller set up as a heat tracing cable temperature limiter (see chapter 1.1.3).
With parameter P16 the communication address (

iter is set. In case no limiter Zone is assigned to the controller Zone the

Adjustment thresholds: 0...30
Default value: 0 (no limiter Zone assigned)

4.3.2 Parameter P17: LIM ZONE

LIM ADDR) of the heat tracing cable temperature lim-

LIM ADDR is set to “0”.

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: heat tracing cable temperature limiter Zone number

• Not valid for Limiter Zones

• Not valid for Current Zones

With parameter P17 the Limiter Zone (
(see chapter 4.3.1) is assigned to the controller Zone.

Adjustment thresholds: 1...16
Default value: same number as temperature controller Zone number

LIM ZONE) number of the heat tracing cable temperature limiter

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4.3.3 Parameter P18: CTR MODE

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: not applicable

• Not valid for Limiter Zones

• Not valid for Current Zones

Parameter P18 determines the TC 816 control mode (

• PID control: The temperature controller Zone controls according to PID (Proportional Integral &

Differential) control algorithm for accurate, fast and smooth temperature
maintenance. The parameters for this algorithm are set with:
Parameter P19: Proportional band (

Parameter P20: Integration time (
Parameter P21: Differential time (

• APC control: The temperature controller Zone controls according to APC (Ambient Proportional

Control) algorithm.
This algorithm is used for frost protection heat tracing circuits allowing huge energy
savings. Ambient temperature is measured by a single ambient temperature sensor
connected to an AF TIT Tracing Input module for Temperature. Every temperature
controller Zone which is assigned to the ambient temperature input Zone (by
parameter P26

Parameter P22: Lowest ambient temperature for which the heat tracing circuit is
designed (

and
Temperature set point of the present circuit.

• ON/OFF control: The temperature controller Zone controls as a mechanical thermostat with a

hysteresis.
The heat tracing is switched ON at:
maintenance temperature set point (in the circuit display) + ½ of the hysteresis
The heat tracing is switched OFF at:
maintenance temperature set point (in the circuit display) - ½ of the hysteresis
The hysteresis is set with:
Parameter P24: Hysteresis (

Adjustment thresholds: 0 = PID control

1 = APC control
2 = ON/OFF control

Default value: 0

Note: In case Parameter P18 (

ter P12 (

ON DELAY) to “0” (zero).

CTR MODE) is set to ON/OFF control it is recommended to set parame-

SENSOR #) will be proportionally controlled between:

CTR MODE). Possible control modes are:

P HEAT)

I HEAT)

D HEAT)

APC MIN T)

HYSTER)

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4.3.4 Parameter P19: P HEAT

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: %

• Not valid for Limiter Zones

• Not valid for Current Zones

Control mode set to PID control, see chapter 4.3.3.

With parameter P19 the proportional band (
centage). The resulting proportional band derives from the TC 816 globally set maximum temperature value

(default 700 °C).
If, for example,

portional band (p-band) is 70°C. For a pure proportional controller (not PID) this means that the controller
output is slowly reduced before reaching the temperature set point. In case the measured temperature equals
the set point the controller output has been reduced to 0 %. This results in the following curve:

P HEAT is set to 10 % and the maximum temperature value is 700 °C, the effective pro-

Contr Outp (Y)

100%

0%

Figure 5.1 Illustration of proportional control mode

P HEAT) of the controlled heat tracing circuit is set in % (per-

Temperature (X)

p-Band
Set Point (W)

Adjustment thresholds: 0...100
Default value: 5

Note: With

P HEAT set to “0” the temperature control acts as ON/OFF control without hysteresis.

4.3.5 Parameter P20: I HEAT

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: s (seconds)

• Not valid for Limiter Zones

• Not valid for Current Zones

Control mode set to PID control, see chapter 4.3.3.

With parameter P20 the integration time of the control system is set in s (seconds). In the event of deviations
this control portion modifies the controller output by a speed set here (up or down).

Adjustment thresholds: 0...999
Default value: 80

Note: With

I HEAT set to “0” the integral portion of the PID control is switched off.

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4.3.6 Parameter P21: D HEAT

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: 0,1 x s (seconds) => value of 10 means 1 s

• Not valid for Limiter Zones

• Not valid for Current Zones

Control mode set to PID control, see chapter 4.3.3.

With parameter P21 the differential time (
algorithm ‘brakes’ the control output for a time which can be set here, in the event of the actual value ap-

proaching the reference value at too high speed.

Adjustment thresholds: 0...999
Default value: 200

Note: With

D HEAT set to “0” the differential portion of the PID control is switched off.

4.3.7 Parameter P22: APC MIN T

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: °C or °F

• Not valid for Limiter Zones

• Not valid for Current Zones

Control mode set to APC control, see chapter 4.3.3.

Parameter P22 determines the lowest ambient temperature (
circuit is designed.

Adjustment thresholds: -40...+5
Default value: -20

D HEAT) is set in 1/10 s (seconds). This portion of the control

APC MIN T) for which the heat tracing

4.3.8 Parameter P23: Spare

This Parameter has no function, it is a spare parameter to give the possibility of future functional expansion of
the TC 816 heat tracing temperature controller.

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4.3.9 Parameter P24: HYSTER

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: °C or °F

• Not valid for Limiter Zones

• Not valid for Current Zones

Control mode set to ON/OFF control, see chapter 4.3.3.

Parameter P24 determines the hysteresis (
tracing temperature controller.

Adjustment thresholds: 1...30
Default value: 4

HYSTER) of the ON/OFF control actions of the TC 816 heat

4.3.10 Parameter P25: CYCL TIME

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: s (seconds)

• Not valid for Limiter Zones

• Not valid for Current Zones

Control mode set to PID control, see chapter 4.3.3.

Parameter P25 determines the cycle time (
the output of the controller within a certain period (
The cycle time is a constant value. Thus, the longer the power is switched ON, the higher the power output

and the shorter the power is switched OFF. The cycle time is always the sum of ON and OFF time.

The shortest switching impulse results from a cycle time divided by 100 as the controller output steps in full
percentage values of the cycle time.

In order to reduce the speed of fast switching outputs suitable for example for mechanical contactors,

CYCL TIME) of the TC 816 controller output. In order to vary

CYCL TIME) the power is switched ON and OFF.

CYCL

TIME is to be increased. An increase in this parameter effects a slowing down of the outputs. This best

cycle time for mechanical contactors depends on the maximum amount of switching cycles the manufacturer
specifies and the duration of the period the maintenance team wishes to use the contactors. This is not an
issue with solid state relays.

Adjustment thresholds: 3...999
Default value: 3

Operation Manual 0503 E TC 816 Page 39 of 42

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TC 816 Operation Manual

4.3.11 Parameter P26: SENSOR #

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: Zone number

• Not valid for Limiter Zones

• Not valid for Current Zones

Parameter P26 determines the temperature controller Zone number to which the reference temperature sen-

SENSOR #) is connected. This option enables that multiple heat tracing circuits with individual load

sor (
current monitoring and MCB/RCD status monitoring can be controlled as:

• Dummy Pipe or Dead Leg sensing process temperature maintenance

• Ambient Proportional Control (also suitable for frost protection)

Adjustment thresholds: 1...16 (only if P28
Default value: own Zone number

Note: This Parameter has no effect if P28

MS MODE is set to default)

MS MODE is not in default position.

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TC 816 Operation Manual

4.3.12 Parameter P27: OUTP #

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: Zone number

• Not valid for Limiter Zones

• Valid for Current Zones

- Zones 17 through 32

- unit in: Temperature Controller Zone number

This option enables:

Multiple Sensor MODE:
A heat tracing circuit can be controlled by multiple RTD temperature sensors (Multiple Sensor MODE).
Very useful for:

• Long line tracing

• Critical line tracing

Multiple sensor control is determined by this parameter P27 and parameter P28.

Parameter P27 determines the circuit number of the applicable temperature controller on which the actual
temperature sensor has effect.

In case multiple RTD sensors are assigned to a circuit and a sensor is broken, a sensor alarm is triggered, but
the circuit will not be shut down, since the circuit keeps controlling on the remaining RTD sensors.

Three Phase Current Monitoring:
In case a TCD 01 Tracing Control Display for three phase current display per tracing circuit, with firmware
AZ 884 (see chapter 3.6) is connected to the TC 826, the three phases of three phase heat tracing circuits
can be monitored individually. Up to 3 current input Zones can be assigned to one temperature Zone in order
to prompt the TCD 01 Display to show the three currents together with the Controller and Limiter tempera­ture in one screen.

For Temperature Controller Zones 1 through 16:

Adjustment thresholds: 1...16 (only if P26
Default value: own Zone number

For Current Zones 17 through 32:

Adjustment thresholds: 1...16
Default value: equivalent own Temperature Controller Zone number

Note: Never adjust this parameter for Zones 1 through 16 other than default (own Zone number) if Parame-

ter P26 (

SENSOR # is set to default)

(own Current Zone number – 16)

SENSOR #) is not in default position.

Operation Manual 0503 E TC 816 Page 41 of 42

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TC 816 Operation Manual

4.3.13 Parameter P28: MS MODE

This Parameter is:

• Valid for Temperature Controller Zones

- Zones 1 through 16

- unit in: Zone number

• Not valid for Limiter Zones

• Not valid for Current Zones

This option enables that a heat tracing circuit can be controlled by multiple sensors (Multiple Sensor MODE).
Very useful for:

• Long line tracing

• Critical line tracing

Adressing of multiple sensors is achieved with parameter P27
controller. In the most extreme case the actual circuit can be controlled by 16 temperature sensors.

Parameter P28 determines the TC 816 Multi Sensor mode (

• MS disabled: Heat Tracing circuit is controlled by the temperature of the in parameter P26 set

• MS MIN: Heat Tracing circuit is controlled by the

addressed to the actual circuit.

• MS AV: Heat Tracing circuit is controlled by the

addressed to the actual circuit.

• MS MAX: Heat Tracing circuit is controlled by the

addressed to the actual circuit.

Adjustment thresholds: 0 = MS disabled

Default value: 0

SENSOR #.

1 = MS MIN
2 = MS AV
3 = MS MAX

OUTP # of all circuits within the applicable

MS MODE). Possible multi sensor modes are:

MINimum temperature seen by all sensors

AVerage temperature seen by all sensors

MAXimum temperature seen by all sensors

4.3.14 Parameter P29: Spare

This Parameter has no function, it is a spare parameter to give the possibility of future functional expansion of
the TC 816 heat tracing temperature controller.

Page 42 of 42 Operation Manual 0503 E TC 816

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