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DIFF
The Safe-NET system is capable of controlling
temperature inside the refrigerated space of a refrigerated
merchandiser. The Safe-NET system can achieve this
control in the various ways discussed earlier. When
ON/OFF control is selected, the control methodology
makes use of a set point and a control band known as a
differential (DIFF). For example: with a DIFF setting of
10, and DSET set point of 10 deg F, the ON/OFF
control method will attempt to maintain the 10 º by
cycling the control device ON at temperatures above 10 º
and OFF at 0 º . This temperature control is superceded by
a fixed minimum ON time of 3 minutes. Hence lower
DIFF settings will result in tighter temperature control
but more frequent control device (compressor, valve)
cycling. Conversely, higher DIFF settings will reduce
control device cycling at the expense of product integrity.
Typically, this setting is at user discretion.
Setting this parameter is done in the SETUP menu. After
navigating to the DIFF sub menu item, the display will
cycle between DIFF and the current setting. While the
setting is being displayed, press ENTER on the Hand-
Held device or press the SELECT button on the
Safe-NET display module to allow editing of the value.
When the Safe-NET display module begins flashing the
value, use the UP or DOWN arrow keys on the Hand-
Held device or the UP /DOWN buttons on the Safe-NET
display module to change the setting.
Once the desired setting is displayed, press the ENTER
key on the Hand-Held device or the SELECT button on
the Safe-NET display module to store the new value to
NV memory. The display will revert to cycling between
DIFF and the new value.
Note:
Typically this setting is lower in frozen applications –
approximately 2 degrees differential.
4-17 P/N 0461391A
Hussmann Corporation • Bridgeton, Missouri 63044-2483 U.S.A.
Safe-NET™
Menu Structure — DIFF