nVent RAYCHEM Elexant 4010i/4020i User Manual
RAYCHEM-AR-H60624-40X0iOpsManual-EN-1905
nVent.com
|
39
4.1.4
Resetting the Safety Limiter
The safety limiter is designed such that after it has tripped, resetting it is possible only after the normal,
safe operating conditions are returned. If the Intelligent Limiting feature is enabled and there was no
current flowing through the heat trace at the time of the over-temperature condition, the safety limiter will
reset itself. If Intelligent Limiting is disabled, or if there was current present in the heat trace during the
over-temperature condition, then the device will need to be reset manually.
In order to manually reset the limiter after it has tripped, the user needs to press the TRIP RESET button
(shown in the Figure below). Alternatively, the limiter can be reset via the touch screen interface, or
remotely using nVent RAYCHEM Supervisor. Refer to the operating manual for nVent RAYCHEM
Supervisor for detailed instructions on how to remotely reset a safety limiter.
Figure 28 - Elexant 4020i-MOD-IS-LIM Front Panel
4.1.5
Setting the Temperature Set Point
4.1.5.1 Choosing a Set Point
The lock out temperature (set point) of the safety limiter must be set in such a way that the maximum
allowable temperature of the equipment is not exceeded. For example, the surface temperature of a
heat-tracing cable in a hazardous area cannot exceed the local maximum temperature allowed based on
the classification rating (T-rating) of the area. The set point should be the maximum allowed temperature
less 5 K for temperatures below or 200°C, or less 10 K greater than 200°C.
4.1.5.2 Configuring the Set Point
Modifying the set point requires physical access to the Elexant 4020i device. The lock out set point may
be configured with the touch screen interface of the device or with nVent RAYCHEM
Supervisor if its user interface is physically close to the 4020i device. The procedure to modify the limiter
set point is the same for all user interfaces. Use your preferred configuration method to enter the set
point and then press the SET CONFIG button on the Elexant device to confirm the set point change.
The SET CONFIG button must be pressed within 30 seconds after the new setpoint has been entered.
If the button is not pressed before this time interval has elapsed, the new value is discarded and the old
set point value remains unchanged. Once the new set point has been saved, the new (or in case the save
procedure was not successful, the old) set point is read back and displayed confirmation to the user.
