Hill-Rom Advanta P1600, Service Manual

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ZoneAire® Sleep Surface Software Theory of Operation
Chapter 3: Theory of Operation
Advanta™ Bed Service Manual (man168ra) Page 3 - 39
3
While in any of the other modes, the air system transitions to the off mode in
two ways:
• The surface power switch is pressed.
• An air system error occurs (not a communication error).
Pressure Relief Mode
While in the pressure relief mode, the air pressures in each of the six bladder
zones are regulated at predefined levels, called trim points. Around each of the
trim points is a “band” which provides a pressure tolerance and creates a
pressure lag. If no correction in pressure is taking place, the band is used as the
reference.
Transition to the pressure relief mode can be made by:
• Pressing the surface power switch while in the off mode.
• Pressing the heel relief 1 switch while in the heel relief 1 mode.
• Pressing the heel relief 2 switch while in the heel relief 2 mode.
• Pressing the heel relief 3 switch while in the heel relief 3 mode.
• Pressing the auto firm switch while in the auto firm mode, only if the auto
firm mode was initiated from the pressure relief mode (mode memory
feature).
• Pressing the auto firm switch while in the CPR mode, only if the CPR
mode was initiated from the pressure relief mode (mode memory feature).
The surface power off LED is lit when the systems are off.
Heel Relief Modes
While in a heel relief mode, certain zones are deflated to near zero pressure
depending on which heel relief mode is selected. Pressures are then regulated,
as described in the pressure relief mode above, at predefined trim points.
When a heel relief mode is entered, a 10-min timer is started. When this timer
expires, the deflated heel zones are inflated to a higher, reliably readable,
pressure, and then immediately deflated back to the trim points defined above.
Transition to a heel relief mode can be made by:
• Pressing any heel relief switch while in the pressure relief mode.
• Pressing any heel relief switch while in either of the other two heel relief
modes.