Programming instructions

Programming equipment settings
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Programming relays for curtain control
Curtains control the temperature by adjusting airflow into the facility. Before setting up the curtains,
make sure you have properly configured the relays. For more information, read Configuring relays
for curtain control on page 22.
Programming curtain control relays means programming the following settings.
 Set point – the temperature at which the curtain holds its position
 Idle band – the buffer around the set point within which the curtains hold their position
 Open run duration – the duration the curtains open during the OPEN cycle
 Open idle duration – the duration the curtains pause during the OPEN cycle
 Close run duration – the duration the curtains open during the CLOSE cycle
 Close idle duration – the duration the curtains pause during the CLOSE cycle
How curtains work
Curtains hold their position while the temperature is within the idle band of the set point. For
example, if the set point is 80°F and the idle band is 2°F, the curtain holds its position when the
temperature is between 79°F and 81°F.
If the temperature rises above the idle band (above 81°F in our example), the curtain opens for the
open run duration. After opening, it holds its position for the open idle duration. If the temperature
is still above the idle band, the curtain again opens for the open run duration and the process
repeats.
If the temperature drops below the idle band (below 79°F in our example), the curtain closes for the
close run duration. After closing, it holds its position for the close idle time. If the temperature is
still below the idle band, the curtain again closes for the close run duration and the process repeats.