Danfoss OBC 82.12 Data sheet

Data sheet

Electronic Oil Burner Control OBC 82.12

Description

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.

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

Function	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.

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 supply voltage is connected.

Flash codes

	Event	Code
	False light	2 flashes
	No flame when safety time elapses	3 flashes
	More than three restarts in the same	4 flashes
	cycle
	Max. waiting time on preheater overrun	5 flashes
	(10 min)
	Supply voltage above 264 V a.c.	6 flashes
	Undervoltage <170 V (automatic)	8 flashes
	Application failure (EMC)	constant
		flashes

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

	Time function/explanation
	Output signals of control
	Required input signals
A’	Initiation of burners with oil preheater OFV

AInitiation of burners without oil preheater

BFlame formation

COperation position

DBurner 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	Interval V1-V2 15 s
t3n	Post-ignition 15 s

* Due to the initialisation of the electronics, it may take up to two seconds before ignition is enabled.

2 | © Danfoss | 2019.10

VD.HN.C1.02