Alarm Features; Error Conditions; Error Messages - Process Technology DQ15D Instruction Manual

display will alternately change between the process value and three dashes
"---". To return to normal "SP1" operation, either press all three keys
(" ", "SET", and " ") simultaneously, or switch OFF the remote switch
wired to terminals #3 and #4.
The control normally displays the actual process temperature. To view
the "P" SET POINT value, press the increase " " button once and re-
lease. The control will display the letter "P" and a decimal point followed
by a number between -40 and +999. After 7 seconds the display will
return to the process value.
Note: The units displayed, ºC, ºF, Hz, volts, mA or ohms are estab-
lished during the setup of the control.
To change the set point value, press the "SET" button while the "P"
Power-Save value is displayed. The value will flash, and can be changed
by pressing the increase " " or decrease " " key. After the desired value
is entered, press the "SET" key once to lock-in the new value into memory.
Note: If the "SET" key is not pressed within 5 seconds, the new value
will be lost and the original value restored in memory.
Alarm Feature
Note: This is not a safety device.
The Alarm feature, which is enabled using the "F3" setting during con-
figuration (see page 28), allows the user to establish a set point above
which the control will enter into an alarm condition. This set point should
be higher than the heat set point. During the alarm condition, both con-
trol relays will de-energize and flash "AAA" on the display.
After enabling this feature, you may view the "ALARM SET POINT"
on the display. Press and release the increase " " button twice. The dis-
play will read "A" followed by a decimal point and the alarm set point
value. After a few seconds the display will return to normal.
Note: No values can be seen unless "F3" is enabled. The units dis-
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played, ºC, ºF, Hz, volts, mA or ohms, are established during the setup
of the control.
To change the "ALARM SET POINT", press the "SET" button while
the alarm set point value is still displayed. The number on the display will
flash. After the number begins flashing, use the increase " " or decrease
" " keys to change the value. After the new value has been entered,
press the "SET" key to lock the new value into memory.
Note: If the "SET" key is not pressed within 5 seconds, the new value
will be lost and the set point value will revert to its previous setting.

Error Conditions

Sensor values that are out of range will generate an error display. For Celsius:
<-40º C or >+538º C. For Fahrenheit: <-40º F or >+1000º F. In the event of
an improperly connected RTD sensor or thermocouple, or if the control reads
an "open" circuit, the message "HHH" is displayed and the control de-
energizes the control relay. In the event the RTD sensor "shorts", the mes-
sage "UUU" is displayed and the control de-energizes the control relay.
Note: Thermocouple "shorts" cause a new junction/measurement point
to be created. This will lead to false readings and dangerous operating
conditions.

Error Messages

If the calibration and setup information stored within the memory be-
comes corrupt or erased, the control will switch to its default calibration/
configuration settings. The display will flash the letter "c" on the left side
when default values are activated. The physical size and position of the
letter "c" will define the exact nature of the problem.
Note: Shorted thermocouples will not result in an error condition. In-
stead, incorrect readings will be displayed.
A small "c" in the upper left-hand corner indicates the control is relying
on default (factory set) calibration values. This happens when the con-
trol is new and has not yet been calibrated (setup).
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