Danfoss OBC 82.12 Data sheet

Data sheet

Electronic Oil Burner Control OBC 82.12

Description

Function

The microprocessor based control OBC 82.12
offers stable and precise timings independent of
variations in supply voltage and ambient
temperature.
The control is undervoltage protected.

The OBC 82.12 controls the cut-in and cut-out of
the oil burner’s components and monitors that
the combustion cycle is performed safely.
When the boiler thermostat (TR) cuts in, heating
of the oil in the oil preheater (OFV) will begin.
Once the release temperature is reached and the
oil preheater’s thermostat (OTR) cuts in, the
burner motor will start the pre-purge and power
will simultaneously be applied to the ignition
(TT). Following the pre-ignition and pre-purge
time, the oil will be released by valve V1 being
opened and subsequently V2 will be opened.
When the boiler thermostat opens after the
heating period power will be cut off and all
relays at the outputs will open and be ready for
the next start-up cycle.

Operating information

OBC 82.12 is equipped with a two-coloured LED
which displays both the operating status and can
indicate the causes of errors leading to lockout.
In the event of operating lockout, the cause of
error can be read out as a flash code by holding
down the reset button for at least 5 seconds and
then releasing it. Undervoltage will, however, be
displayed automatically. Reset can be performed
directly in alarm mode (constant red light) or in
flash code mode by pressing the reset button for
at least 0.5 seconds, but no more than 3 seconds.
In flash code mode it is possible to return to
alarm mode by holding down the reset button
again for at least 5 seconds.

In case of undervoltage the control will prevent
the burner from starting and simultaneously
show a flash code. Besides this, up to five other
fault types can be read out as flash codes when
the control is in lockout.
The design complies with the requirements of
the RoHS and WEEE directive.

Application and features

• For 2 stage burners up to 30 kg/h

• For burners with or without preheater

• Precise and reproducible timings

• Limitation at 3 restarts by flame failure within
the same operating period

• Limitation of 10 min. on preheating time

• Remote alarm output

• Indication of reason for lockout

• Indication of preheating and operation

Normal operation

When the boiler thermostat (TR) cuts in, the reset
button flashes green. As soon as the preheater
thermostat (OTR) cuts in, the reset button lights
up constant green. When the boiler thermostat
cuts out, the green light turns off.

Errors during operation (flash codes):

• If the mains voltage falls below 176 V before
start-up, the control will be blocked from
starting. If the mains voltage falls below 165 V
during operation, the oil supply and burner
will be stopped. In both cases, the reset
button will automatically flash 8 times.
When the mains voltages reaches 176 V, the
control will restart as normal. Please note
that the control cannot be reset if the mains
voltage is below 165 V.

• If the mains voltage exceeds 264 V, the control
will automatically enter alarm mode.
The purpose of the overvoltage cut out is
not simply to protect the electronics in the
control, but also the other components in
the burner.

• If light is registered in the final stage of the
pre-purge time, the control will not release
oil and will enter alarm mode.

• If no flame is established at the start, i.e. by
the end of the safety time, the control will
enter alarm mode.

© Danfoss | 2019.10

VD.HN.C1.02 | 1

Data sheet Electronic Oil Burner Control OBC 82.12

• In the event of a flame failure during
operation, the oil supply will be cut off after
no more than 1 second and the control will
restart the burner. If flame failure occurs more

than three times in the same operating period
(TR connected), the control will enter alarm

mode.

• If the release temperature in the preheater is

not reached within 10 minutes, the control
will enter alarm mode.

The OBC 82.12 processor also monitors the
outputs at TT, V1 and V2. If errors like electrical
noise (EMC) are registered at the outputs, the
control will enter alarm mode.

Note:

OBC 82.12 can only be reset while the sup ply voltage is connected.

Flash codes

Event Code

False light 2 flashes

No flame when safety time elapses 3 flashes

More than three restar ts in the same
cycle

Max. waiting time on preheater overrun
(10 mi n)

Supply voltage above 264 V a.c. 6 flashes

Undervoltage <170 V (automatic) 8 flashes

Application failure (EMC)

4 flashes

5 flashes

constant

flashes

2 | © Danfoss | 2019.10

Symbols

Boiler thermostat

High temperature cutout

Ignition unit

Burner motor

Solenoid valve

Photo unit or UV sensor

External alarm

L Phase wire

N Neutral wire

Oil preheater ⁄ Oil preheater thermostat

Hold relay

* Due to the initia lisation of the electroni cs it may take up to two secon ds before ignition is enabl ed

Time function/explanation

Output signals of control

Required input signals

A’ Initiation of burners with oil preheater OFV

A Initiation of burners without oil preheater

B Flame formation

C Operation position

D Burner stop

tw Heating of oil preheater until OTR switches on

t1 Pre-purge 13 s

t2 Safety time 10 s

t3* Pre-ignition 13 s

t4 Inter val V1-V2 15 s

t3n Post-ignition 15 s

VD.HN.C1.02