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 - 35
3
ZoneAire® Sleep Surface—Mattress Plumbing
The mattress contains three individual bladders segmented into nine separate
sections. There is a port on the left side of each bladder that connects the
bladders to their corresponding valve located in the foot end of the mattress
and possibly to another bladder. This port is used only for inflating and
deflating the bladder.
There is also a port on the right side of each bladder that connects the bladders
to their pressure sensor located at the foot end of the mattress and possibly to
another bladder. This port is used only to sense the air pressure in the bladder.
The pneumatic-related components in the system include the compressor (air
pump), the flow direction switching valve, and the muffler.
The muffler minimizes noise as air is pumped into and out of the ZoneAire®
Sleep Surface system. A hose connects the muffler to the flow direction
switching valve.
The flow direction switching valve controls the bi-directional airflow in the
system. The hoses on the switching valve lead to the mattress, the muffler, and
the input and output of the compressor. A 120V AC solenoid changes the valve
position. When the flow direction switching valve is deenergized (its normal
state), air is pulled in by the compressor directly from the muffler. The air from
the compressor then passes back through the valve and out to the mattress. This
sequence is repeated whenever air is needed to inflate the mattress.
For system functions that require airflow out of the bladders, the air control
board supplies 120V AC to energize the flow direction switching valve. With
the compressor on, air is pulled from the mattress, through the compressor,
then back through the switching valve and out the muffler.
Airflow through the pump is always in the same direction.
ZoneAire® Sleep Surface Software Theory of Operation
Essentially all intelligent communications and control are performed by the
controller circuit. This document is intended to describe the operation of the
software, internal to the controller circuit, that provides this intelligence. While
the concentration is on software, this description should provide a better
understanding of operation of the entire system.