Strebel SC40, User Manual

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Coopra Advanced Heating Technologies b.v. Installation and user manual EN_FMT
24
CHAPTER 6. BURNER STATES and MONITORING
6.1. BURNER STATES
Pump
Standby Pre rinse Ignition In operation Post rinse
afterrun
Standby
heat demand
fan
gas valve
glow igniter
ionisation
pump
t=0sec t=3sec t=7sec t<12sec
6.1. Standby
Fan off - Gas valve off - Igniter off - Ionisation off
During the standby, a check is made to see if there is burner
demand. If so the boiler will go over to pre rise.
If the glow igniter counter is too high (the boiler made too many
starts repeatidly) the regulation blocks the burner demand.
Once per hour, if there is no heat demand, the difference
between flow and return temperatures must be less than ± 5°C.
If this is not the case, the pump will be switched on and a check
will be made for a maximum of 10 minutes to see whether the
temperature difference goes to within ± 5°C.
The display shows flashing ‘8’.
If a false flame signal is detected during standby for more than
5 seconds, the regulation runs into lock-out with flashing
indication ‘8’:
6.2. Pre rinse
Fan on - Gas valve off - Igniter on - Ionisation off
The difference between flow and return temperatures must be
less than 20°C before each burner start.
Pump:
At each new heat demand first the pump is switched off for 3
seconds and the water pressure (static pressure) is measured
and stored in the software.
Then second the pump is switched to high speed and the water
pressure (active pump pressure) is measured and stored in the
software.
If the difference between the active pump pressure and the
static pressure is between 0.05 and 0.54 bar a correct water
flow throuhg the heat exchanger is present and the ignition time
starts.
If the difference is less than 0.05 bar or more than 0.54 bar the
regulation locks. The display shows ‘P’. The regulation runs into
the “pump test program”.
Fan:
The fan is switched on at the desired purging speed.
After a few seconds, the fan goes from purging speed to the
faster ignition speed.
Glow igniter:
The glow igniter is switched on at the same time as the fan.
The display shows flashing ‘5’.
When the measured fan speed deviates from the desired speed
the regulation blocks.
After 60 seconds the regulation runs into lock-out, with flashing
indication ‘5’.
6.3. Ignition
Fan on - Gas valve on - Igniter on/off - Ionisation off/on
The fan is running at the ignition speed. The gas valve is
activated. The glow igniter ignites the gas / air mixture from the
burner. The glow igniter will be switched off as soon as an
ionisation signal is measured.
If there is no ionisation at the end of the safety time, a new
attempt at ignition will be made if this was not the last permitted
(third) attempt at starting.
6.4. In operation
Fan on - Gas valve on - Igniter off - Ionisation on
Temperature test:
To ensure the water flow through the heat exchanger a
temperature test is activated.
The difference between flow and return temperatures must be
raised by 3°C within 20 seconds after each burner start.