Operation Notes; Division 1 Z-Purge - Daisy 9017 User Manual

Model 9017 Y/Z-Purge Operator Interface

6 Operation Notes

6.1 Division 1 Z-Purge

When using a Z-purge system, it is the operator's responsibility to disconnect power
and signal paths in the event of a purge failure (that is, if the pressure in the unit falls
below a preset level). Such a failure is indicated by several means. DAISY units are
equipped with both an indicator light (the "Pressure Good" LED shown on drawing
P017) and an internal pressure meter (shown on the same drawing). If the "Pressure
Good" indicator is extinguished, or if the internal pressure meter is in the red zone
below 1" of water column, the operator should immediately disconnect power and
signal connections to the unit using switches
DAISY's Z-purge systems are also equipped with alarm contacts that switch state
simultaneously with the "Pressure Good" indicator. These can be connected to an
alarm system or supervisory control system to provide further indications to the
operator and/or the supervisory system. The operation of the alarm contacts and the
"Pressure Good" indicator light is detailed in the flowchart shown in Figure 6.1 and in
Table 6.1 on page 10.
Power
Off
Off
On
On
February 2022
Figure 6.1 Z-Purge Alarm Logic
Pressure NC1 & NC2
< 0.4" W.C.
Closed
> 0.4" W.C.
Closed
< 0.4" W.C. Open
> 0.4" W.C. Closed
Table 6.1 Z-Purge Alarm and Indicator States
in a safe area.
NO1 & NO2 Pressure (LED)
Open
Open
Closed
Open
10
Daisy Data Displays, Inc.
Off
Off
Off
On
D011-000002