7
x
Gas burner
ROTEX GCU compact -
39
Controlling the burner output
The control determines the required flow temperature based on
the set operating parameters and passes it to the firing unit of the
gas burner. The combustion controller calculates the required
burner output from the target value and the values from the flow
and the return flow temperature sensor. The determined output is
passed to the burner fan as a PWM signal. The burner fan imme-
diately adjusts the gas fan speed and as such the combustion air
flow. The gas controller controls the gas volume accordingly.
Firing unit CM434
The microprocessor-controller gas firing unit CM434 controls and
monitors the firing programme and the temperature sensors for
the flow and return temperature.
7.2
Safety function
Fault shutdown and malfunction indicator
You can find an overview of the interlocking- and temporary fault
shutdowns in chapter 10.3, tab. 10-2 to tab. 10-4).
A fault is displayed:
–
by the red backlight in the display,
–
by a clear text fault message with the fault code in the display
on the control section.
Unlocking the burner
Interlocking faults detected by the automatic firing can only be
reset manually directly on the boiler.
Requirements: The cause of the malfunction is rectified, the
burner is electrically connected.
1. Switching ROTEX GCU compact on.
2. Push the Exit button (fig. 6-1, item 15) for at least 5 secs.
Î
Menu
"Special Level"
is displayed.
3. Select the
"FA failure"
level with the rotary switch.
Î
Error code and prompt "Reset?" is displayed.
4. Select "Yes" with the rotary switch.
5. Confirm the changes with a brief push of the rotary switch.
Î
Fault is reset.
6. Cancelling and jump back by pushing the Exit button again.
7. If there are several successive fault shutdowns, check the
heating system (e.g. flue system, fuel supply).
7.3
Burner setting
Tab. 7-2 Possible adjustment ranges
If changes have been made to the power settings of the burner or
if it has been converted to a different type of gas, this must be
logged in the operating manual and entered on the setting type
plate (fig. 7-3).
The changeover must be provided with the date of implemen-
tation and the signature of the installer.
An interlocking fault can only be reset manually from
the controller of the GCU compact (see chapter 10.4).
With a temporary fault shutdown the burner is switched
off for at least 60 secs.
When the above conditions are back in the normal
working range, a burner release is carried out automat-
ically.
The cause of the last fault is saved in the unit and can
be reconstructed on restarting the unit, even after
power failure.
If more than 5 faults are reset within a 15 minute period,
the fault code E96 is displayed. Another release in then
only possible after 15 mins.
DANGER OF EXPLOSION!
Escaping gas is a direct threat to human health and
safety. Even a few sparks can cause major explo-
sions.
Ɣ
Before working on gas-conducting parts, always
close the gas isolating valve first.
Ɣ
If you can smell gas, air the room thoroughly.
Prevent sparks or flames from arising (e.g. naked
flame, electrical switches or mobile phone).
Ɣ
Only heating specialists authorised and trained by
the gas or power supply company should be
allowed to work on gas-conducting parts.
CAUTION!
An inappropriate setting of the oil burner can lead to a
prohibited level of pollutant emissions, heavy contam-
ination and increased oil consumption.
Ɣ
Burner setting should be carried out only by
authorised and recognised heating engineers.
Type
GCU compact
Blower type
(Manufac-
turer)
Burner
surface
Adjustable load
in kW
315 / 515
Type 118
Type A
6.5 - 15.7
324 / 524
6.5 - 25.3
533
6.5 - 32.5
(6.5 -30.0)*
*
Liquid gas setting
Fig. 7-3
Settings type plate
