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 - 43
3
System Errors
The controller has built in self-diagnostics that are designed to detect system
failures that may not be easily identifiable otherwise. These failures cause the
system to transfer to the off mode and repeatedly flash a code on the footboard
control panel service required LED.
For the ZoneAire® Sleep Surface, the code consists of a certain number of
short flashes that indicate which error has occurred. The code is continually
repeated with a long pause separating the short flashes.
Slow Leak Error
In all modes, except the off mode, the system is checked for slow air leaks
every 5 min. A slow leak is small enough that the pump inflates to the proper
pressure, but large enough to cause the system to correct too often.
To detect small leaks, a counter is incremented whenever an inflate sequence
occurs and is cleared whenever a deflate sequence occurs. This counter
represents the number of inflates without a deflate.
When the 5-min timer expires, the number of inflates without a deflate is
checked for being greater than 20. If this number is greater than 20, a slow leak
error is flagged, the operating mode transitions to off, and the footboard
control panel service required LED repeatedly flashes code 1. If it is less than
or equal to 20, the counter is cleared, and the 5-min timer is restarted.
The ability to detect a slow leak is much greater in the auto firm mode where
the pressures are much higher and, therefore, leak more. If you need to
troubleshoot a system with this error, do so while in the auto firm mode.