Setra Systems Flex - Page 23

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Example #1
In the example on the screen below, Control Assignment
#1 is dedicated to controlling a hydronic reheat valve.
The desired FLEX conguration is to dene Occupied
and Unoccupied room temperatures, intended to deliver
energy savings when the room is not in use. Control Preset
A is going to be the Occupied state, and Control Preset B is
going to be the Unoccupied state.
Set Control Preset A as follows:
• Set Point to 72°F
• Low Limit 65°F
• High Limit 78°F
This means when Room Prole “Occupied” is selected,
the room will be controlled to maintain 72°F temperature.
If the end-user chooses to override the temperature,
they cannot select a temperature lower than 65°F or a
temperature higher than 78°F. FLEX limits the range in this
manner if:
Set Control Preset B (not shown) as follows:
• Set Point to 78°F
• Low Limit 72°F
• High Limit 80°F
ThismeanswhenRoomProle“Unoccupied”isselected,
the room will be controlled to maintain 78°F (warm
climate) temperature. If the end-user wants to lower the
temperature via override, they cannot select a temperature
lower than 72°F or a temperature higher than 80°F. FLEX
limits the range in this manner if desired.
Low Limit and High Limit should be set to the physical
limitations of the devices used.
Example #2
A ventilation VAV damper or valve actuator can also be
controlled, enabling differential pressure regulation in a
room.
Control Assignment #2 is dedicated to controlling an
actuator. The desired FLEX conguration is to dene
Isolation and Non-Isolation room pressures, intended to
manage room differential pressure alarms when the room
is not in use. Control Preset A is going to be the Isolation
state, and Control Preset B is going to be the Non-Isolation
(or normal patient room use) state.
Set Control Preset A as follows:
• Set Point to 0.01”WC
• Low Limit 0.01”WC
• High Limit 0.01”WC
ThismeanswhenRoomProle“Isolation”isselected,the
room ventilation will be controlled to maintain 0.01”WC
differential pressure. If the end-user tries to override the
pressure, they cannot change anything. FLEX limits the
range in this manner.
Set Control Preset B as follows:
• Set Point to 0.00”WC
• Low Limit 0.00”WC
• High Limit 0.01”WC
ThismeanswhenRoomProle“Non-Isolation”isselected,
the VAV control will not try to modulate airflow to achieve
any differential pressure, with the door open or closed. If
the user chooses to close the door and modulate pressure
override to 0.01”WC, that is permitted.
Operation