66/248
Building Technologies Division Basic documentation LMV36... CC1P7544en
Infrastructure & Citiies Sector 7 Basic unit 25.09.2013
7.5.4 Valve proving via gas pressure switch-min X5-01
Bild 411e/1010
P LT
(Pmin)
P LT
(Pmin)
Figure 2: Valve proving via gas pressure switch-
min
Step 1: t80 – evacuation of test space.
Gas valve on the burner side is opened to bring the test space to
atmospheric pressure.
Step 2: t81 – atmospheric pressure test.
When the gas has closed, the gas pressure in the test space must
not exceed a certain level.
Step 3: t82 – filling of test space.
Gas valve on the mains side opens to fill the test space.
Step 4: t83 – gas pressure test.
When the gas valve has closed, the gas pressure in the test space
must not drop below a certain level.
Legend
t80 Evacuation of test space (parameter 242)
t81 Atmospheric pressure test (parameter 243)
t82 Filling of test space (parameter 244)
t83 Gas pressure test (parameter 245)
V… Fuel valve
Pmin Pressure switch-min
P LT Pressure switch
valve proving
Input/output signal 1 (ON)
Input/output signal 0 (OFF)
Input permissible signal 1 (ON) or 0 (OFF)
Performing valve proving via gas pressure switch-min affects the program
sequence as follows (see Addendum Sequence diagram «G
»):
a) Valve proving on startup:
Gas pressure switch-min (gas shortage test) is not sampled in phase 22, but
during valve proving at the end of the filling time.
b) Valve proving on shutdown / deactivated:
Gas pressure switch-min is sampled after preignition. For that purpose, a new
phase 39 (Pmin test) is introduced and, at the end of the phase (duration of
phase = filling time).
In practice, this represents an extension of preignition by the
filling time, if valve proving via gas pressure switch-min was selected.
Valve proving test can only be made via the gas pressure switch-min.
The pressure switch must be fitted between the valves.
This has an impact on the program sequence (refer to chapter Sequence diagrams).
Valve proving continues to be activated via parameters 241 and 341.
7.5.4.1. Lockout phase (phase 00)
The relays of the fuel valves and the safety relay (fan) are deenergized, the alarm relay
is energized and lockout takes place. This means that phase 00 can only be quit via a
manual reset. The time of phase 00 is unlimited.
To Next Page
Loading...
