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Raychem-AR-H58692-ACS30UIT2Programming-EN-1805
Power Cycle Test Interval:
The frequency to run the Power Cycle Test
Range:
Never, Daily, Weekly and Monthly
Default: Never
3.6.3.
TEMP CONTROL – PASC CONTROL
Fig. 3.59
Fuel Oil Temperature PASC Control window
The Temp Control window allows you to select the temperature control mode to Ambient Control,
Line Control or PASC. This option depends on where the controlling RTD inputs are situated and
utilized: either measuring the temperature of the environment surrounding the pipe (ambient), or
directly on the pipe itself (line). Tap PASC
Fig. 3.60
Setup|Fuel Oil PASC Control window
PASC (Proportional Ambient Sensing Control):
PASC takes advantage of the fact that the heat
loss from a pipe is proportional to the temperature difference between the pipe and the ambient
air. This is true regardless of heater type, insulation type, or pipe size. Once the heat tracing and
insulation on a pipe has been designed to balance heat input with heat loss for maintaining a 40°F
pipe, the main variable in controlling the pipe temperature becomes the ambient air temperature.
The ACS-30 system has a control algorithm that uses the measured ambient temperature, the
desired 40°F maintain temperature, minimum ambient temperature assumption used during design,
and size of the smallest pipe diameter to calculate how long the heater should be on or off to
maintain a near-constant pipe temperature.
