Cobra CS9, Руководство по обслуживанию

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3
Operation
10
© Moffat Ltd, August 2012
Revision 3
Moffat Cobra Series CS9 - Gas Salamander
Millivolts are provided to the electromagnet by
the thermocouple (not shown) which generates
millivolts when heated. The thermocouple screws
into a fitting at the back of the gas valve to make
an electric connection. By pressing in the gas
control knob, the plunger can be temporarily held
open while lighting. There's two reasons for this;
gas has to flow through the safety valve to make
it possible to light the main burner, and secondly
the plunger has to be pushed all the way in for
the electromagnet to hold it in. i.e. the electro-
magnet is strong enough to hold the plunger in
once there, but is not strong enough to pull it in
by itself.
Sometimes a problem with the flame not staying
lit after releasing the button, can be attributed to
the plunger not being pushed all the way in.
Electromagnetic Flame Failure Gas Valve
The purpose of the safety valve is to shut off the
flow of gas if the main flame goes out.
Inside the body of the gas valve is an electro-
magnet connected to a spring loaded plunger.
When the electromagnet is energized, it holds the
plunger in, allowing gas to flow through the valve.
When the electromagnet is de-energized, the
plunger snaps to the closed position, stopping the
flow of gas to the main burner.
Figure 3.4b
Thermocouple
Gas flow
Electromagnet
Plunger
Shaft
Knob
Gas flow
Plunger