nvent 910 Series Installation, Operating And Maintenance Instructions page 29

Range: 3 to 33,000 Watts
Procedure: Adjust the MAXIMUM POWER level to the desired value (watts). Use the TEST
TRACING function to observe the power limiting operation.
IMPORTANT:
• This function may be set within reasonable limits for the particular tracer being powered.
The effective resolution of the setting is limited to 1/30th of the calculated full on power.
• Do not set the MAXIMUM POWER below full output for applications that do not require
power limiting.
5.2.10 TS FAIL MODE
Purpose: This parameter determines whether the HTC turns the output switch ON or OFF if all
selected temperature sensors fail to provide a valid control temperature.
Setting: OFF or ON
Procedure: If the HTC should turn the output switch off when it cannot read a valid control
temperature, then select OFF, otherwise if the output switch should turn on, then select ON.
IMPORTANT: This parameter is part of the TS CONTROL MODE.
5.2.11 TEMPERATURE SENSOR CONTROL MODE
Purpose: The TS CONTROL MODE allows the selection of one of eight possible temperature
control modes for the controller. The different modes allow redundant fail-safe temperature
sensing, averaging, or minimum maintain temperature control.
Setting: Select one of the following eight possible modes:
CONTROL TS AND DESCRIPTION
CONTROL USING TS 1, FAIL OFF/ON
CONTROL USING TS 1, FAIL TO TS 2
CONTROL USING TS 2, FAIL OFF/ON
CONTROL USING TS 2, FAIL TO TS 1
CONTROL ON AVERAGE, FAIL OFF/ON
CONTROL ON AVERAGE, FAIL TO GOOD
CONTROL ON LOWEST, FAIL OFF/ON
CONTROL ON LOWEST, FAIL TO GOOD
Where OFF/ON = Controllers' output switch turned OFF or ON as determined by the TS FAIL MODE.
Example: With a TS CONTROL MODE of CONTROL ON AVERAGE, FAIL TO GOOD, the controller
will measure both sensors (TS 1 and TS 2), averaging the two temperature values, display the
results, and cycle the heater ON or OFF to maintain the CONTROL SETPOINT temperature. This
is the primary control mode. If either sensor should fail, the controller will transfer control to
the remaining "good" sensor and generate the appropriate TS 1 or TS 2
FAILURE ALARM (assuming that the alarm is enabled). The temperature will now be
maintained based on this measured value. If the remaining "good" sensor fails, the controller
will turn the heater OFF or ON as determined by the TS FAIL MODE setting. The appropriate TS
1 or TS 2 FAILURE ALARM will be also be generated.
Procedure: Select the control mode that best suits the application.
IMPORTANT: Ensure that TS FAILURE ALARMS are enabled. See Sections 5.4.1, 5.4.4, and
5.4.10 for a complete explanation of RTD failure detection in the HTC.
5.2.12 TS 1 TYPE
Purpose: This parameter specifies the type of RTD that is connected to the HTC's TS 1 input.
Setting: 3 wire 100 Ω Platinum or 2 (or 3) wire 100 Ω Nickel Iron (NI-FE).
Procedure: Select the type of RTD that is connected to the TS 1 input.
IMPORTANT: If a 2 wire 100 Ω Nickel Iron (NI-FE) RTD is selected then the TS 1 LEAD
RESISTANCE must be entered manually (see Section 5.2.13).
5.2.13 TS 1 LEAD RESISTANCE
(For NI-FE RTDs only.)
nVent.com | 29