Lamtec ETAMATIC, Руководство пользователя

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8 Control Mode
8.2 Leakage test
The leakage test checks whether the main gas valves are leak-tight. The supply gas pressure
is used for this purpose. Since the leakage test line (space between the two main valves)
burns empty in the event of a shut-off, this part is normally without pressure when starting (gas
pressure > min. = 0). The ETAMATIC checks this. Main gas 1 is then opened shortly and gas
flows into the test line (gas pressure > min. changes from 0 to 1). This pressure must then
subsist for 30 seconds. The leakage test is then deemed to be completed.
If the leakage test line is not empty at the start (e.g. as a result of a previous fault shut-down),
main gas valve 2 opens first. The leakage test line is vented (into the combustion chamber or
over the roof, depending on the system; for suggested circuit, see Appendix). It is checked,
whether the line remains pressureless for 30 seconds. Otherwise the procedure is, as de-
scribed previously.
The leakage test is performed before ignition.
The pressure monitor for the leakage test line must be connected to "Gas pressure >min" input
(terminal 47). It also monitors the minimum pressure during operation. If another minimum
pressure should to be monitored during operation, the pressure monitor is, to be looped into
the gas safety interlock circuit, for this purpose.
However, the test line must be designed to ensure that the test time of 30 seconds per valve
is sufficient for reliable detection of a 0.1% leak of the fuel gas consumed at maximum com-
bustion heat output, but at least 50 dm
3
/h.