TC 816 Operation Manual
THERMON…The Heat Tracing Specialists
®
Page 4 of 42
Operation Manual 0503 E TC 816
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 com-
municate 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 tem-
perature 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.
