2
APPLICATION TECHNOLOGY FEATURES
1. Flame Monitoring
The flame monitoring can be effected with the following
flame detectors:
– With ionization electrodes
in power grids with earthed
neutral conductor, utilizable with gas burners (interference
effects of the ignition spark cannot influence the formation
of the flame signal).
– With infrared flicker detector
type IRD 1020 for all types
of burners.
2. Burner Control
– The burner controls features a low-voltage protection. If
the supply voltage dropps below 160 V during operation,
the burner switches-off. When the supply voltage raises
above 180 V, the burner performs a restart independently.
– The automatic burner controls MMI only operate, when a
load is connected to terminal
5. If the fuel valve is
interrupted by an external contact during the pre-purging
phase, a resistance of max. 22 kW, 4 Watt has to be
applied bet-ween the terminals 5 and 8.
– Functional test of the air pressure monitor before the
startup and monitoring of the air pressure during the pre-
purging time, as well as in the operating condition of the
burner. For normal applications a working contact with a
power rating of 4 A / 220 V is sufficient.
– In the case of the automatic control MMI 813.1, contacts
can be installed between the terminals 1 and 9 (e.g., valve
limit position contacts).
These are checked for their
correct closing position when the unit is started up. The
connection 1-9 has to be closed during the starting
phase of the automatic control.
3. Safety
With respect to design and programme sequence, the gas
burner automatic safety controls of the MMI type range
comply with the currently applicable European standards
and regulations.
4. Mounting and Electrical Installation
Wiring base:
– 3 earth terminals with additional terminal for burner
earthing
– 3 neutral terminals with internal permanent connection to
neutral terminal 8
– 2 independant spare terminals (S1 and S2)
– extra terminals A, B and C are standard
– 2 slide-in plates and 2 easy knock out holes (PG11
thread) plus 2 knock out holes in the base bottom faciliate
the base wiring
General:
–
Mounting position
as required, insulation standard IP 44
(splash-proof). The automatic control and sensor should,
however, not be exposed to excessive vibration.
– During mounting and installation, the applicable regula-
tions for installation
have to be observed.
COMMISSIONING AND SERVICE/MAINTENANCE
1. Important Remarks
– Before commissioning, the wiring has to be accurately
checked. Faulty wiring can damage the unit and endanger
the safety of the installation.
– The mains fuse
has to be selected so that the limit values
indicated under "Technical Specifications" are under no
circumstances exceeded. Non-compliance with this
regulation can have very serious consequences for the
control unit and for the installation in the case of a short-
circuit.
– For safety reasons, at least one control shut-down per
24 hours
must be assured.
– The control unit must be plugged-in or -out only when the
mains supply has been disconnected.
– Automatic burner safety controls are safety devices and
must not be opened.
2. Functional Check
During commissioning and after an overhaul of the burner,
the following checks have to be carried out:
a) Starting test with closed manual valve and bridged gas
monitor contact:
– The device must go into a fault condition
after the
safety period has elapsed.
b) Close the manual valve in operating position with the gas
monitor contact bridged.
– The device must go into a fault condition after a flame
failure.
c) Air pressure monitor contact interrupted:
– Device goes into a fault condition.
d) Bridge air pressure monitor contact before starting:
– Device must not start.
3. Trouble Shooting
Burner does not go into operation, programme indication
remains:
– Electrical connection defective
– Thermostat or gas monitor "OFF"
Burner does not go into operation, programme indication
rotates continuously:
– Air pressure monitor defective, respectively, not in starting
position. (Working contact must be
open).
– Connection term. 1 - term. 9 interrupted
– mains voltage < 180V
The automatic control switches to fault condition shortly
after the start of the pre-purge time (line within the blue
zone):
– Air pressure monitor contact does not close
– No load on terminal 5
– Flame signal
Automatic control switches to fault condition during the pre-
purge (blue zone):
– Air pressure monitor contact open
– Flame signal (stray light)
Automatic control switches to fault condition during the
safety time (yellow zone):
– No flame formation (ignition missing, valve does not
open, etc.)
– No flame signal or too weak flame signal (flame does not
adhere, poor insulation of the flame detector, burner not
properly connected to the earth conductor).
Automatic control switches to fault condition during the
operating position (red, resp. green zone):
– Flame lift-off
– Air pressure monitor contact opens
– Flame signal too weak.
MMI 813.1