nvent RAYCHEM T2000 User Manual

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2. Communications are interrupted between the control module and the GCC (as in the case of
a damaged communications wire or loss of power to the GCC). Approximately 30 seconds
after communications ceases, the control module will return to normal operation.
3. Communications between the control modules and the GCC goes “Off-line” for at least two
minutes (as occurs when the Handheld Programmer (Model 760/HHP-9000) or the Panel
Mount Programmer (Model 761) is used to communicate with the control module).
4. Fail safe operation begins. If this occurs the output will go on. However, the three-character
display will still flash “PrI” when the load current would normally be displayed.
IMPORTANT:
• The control module will return to normal operation if communications between the GCC
and the control module are disrupted in any way. This will return temperature control to the
control module.
• The control module does not perform a periodic auto-cycle test while in load shedding
mode.
• For the CM 2000+ control module, fail safe mode is always disabled if the SWITCH
CONTROL MODE is set to either of the two proportional ambient control modes.
• If the FAIL SAFE MODE parameter is enabled, then at least one LOW TS TEMP ALARM (of a
TS used in the TS CONTROL MODE) must be enabled. The associated LOW TS TEMP ALARM
temperature must be less than the CONTROL SETPOINT temperature, otherwise the control
module will not go into load shedding mode.
• If the TS CONTROL MODE uses both TS 1 and TS 2 to calculate the control temperature, the
control module will turn on its output if the following conditions are met:
– Load shedding is active
– The FAIL SAFE MODE parameter is enabled
– Both TS 1 and TS 2 have their LOW TS TEMP ALARMS enabled
– The control temperature falls below either of the LOW TS TEMP ALARM temperatures
• For a control module configured as an ATC MASTER, a load shedding or fail safe command
does not affect the ATC output signal.
• For a control module configured as an ATC SLAVE, a load shedding command has higher
priority than the ATC signal from an ATC MASTER.
• The FAIL SAFE MODE parameter should always be disabled for a control module configured
as an ATC SLAVE.
• If a control module is programmed to be associated with more than one of the four
GCCcontactinputs,thenalloftheenabledGCCcontactinputsmustbeactuated
(in the load shedding command issued by the GCC) before the control module will go into
load shedding mode.
5.4 AMBIENT TEMPERATURE CONTROL (ATC) MODE
Ambient Temperature Control (ATC) is achieved by at least one control module (ATC MASTER)
controlling the outputs of one or more control modules (ATC SLAVES) using an ATC signal.
An ATC MASTER has an ambient temperature sensor connected to at least one of its RTD
inputs. An ATC SLAVE does not require a temperature sensor to be connected to either of
its RTD inputs. This allows a number of tracing points to be controlled using one or more
temperature sensors, eliminating the need for temperature sensors on each control module.
A control module cannot be both an ATC MASTER and an ATC SLAVE.
The ATC signal from an ATC MASTER will either instruct the ATC SLAVES to turn their outputs
on or off, or it will be absent. If the ATC signal is absent then the output of an ATC SLAVE
will be off.
For more information regarding a control module configured as an ATC MASTER see Section
3.4.12. For more information regarding a control module configured as an ATC SLAVE see
Section 3.4.11.
The two RTD inputs and the corresponding TS alarm settings of an ATC SLAVE are available for
monitoring applications and are not used in controlling the output.

nvent RAYCHEM T2000 Specifications

General

Brand	nvent
Model	RAYCHEM T2000
Category	Controller
Language	English