Honeywell DKG 972 User Manual

Gas Burner Safety Control DKG 972

For 2-stage atmospheric gas burners

Flame detection:

- Ionisation probe

- Infrared-flicker detector IRD 1020.1

- UV flame sensor UVD 971

INTRODUCTION

The burner control box DKG 972 controls and supervises
atmospheric burners for gas. They are approved and certified
according to the applicable European standards and
regulations.
The microprocessor-based programming sequence ensu­res extremely stable timings independent of voltage varia­tions, ambient temperature and/or switch-on cycles. The
built-in information system not only provides a continuous
monitoring of the actual state of the box (very helpful es­pecially for monitoring the start-up phase) but also informs
about the cause of a possible lock out. The lock out cause
is stored in such a way that it can be retrieved even after a
power failure.
The control box is designed for maximum safety in case of
fluctuations in the voltage supply. If the mains voltage drops
below the permitted level, operation is interrupted and the
control box automatically prevents the start sequence from
being repeated. In this way, the safety of the system is not
put at risk by a drop in the mains voltage. This low-voltage
protection works not only during start-up but also perma­nently during operation.

CONSTRUCTIONAL FEATURES

The control box circuitry is protected by a flame resistant,
transparent plug-in type plastic housing. A central fixing
screw locks the control box to the wiring base.
The plug-in control box incorporates the microprocessor
based timer, flame check and reset circuits.
Manual reset from lock out and set to lock out is provided by
a push button with an integrated LED information system.
A variety of cable entry points provides complete flexibility
for electrical wiring.
The wiring base S98 is equipped with spare- and extraterminals
and allows together with a variety of cable entry points utmost
flexibility of electrical wiring.

The DKG 972 are compatible with the TFI 812.
Different are only the pre- and post-ignition times.

Max. heating power according the limits in the Gas Appliance
Directive.

TECHNICAL DATA

Operating voltage 220 / 240 V (-15... +10%)

or 110 / 120 V (-15... +10%)

Fuse rating 10 A fast, 6 A slow
Power consumption ca. 12 VA
Max. load per output

- term. 3 ignition trafo 1.0 A, cos ϕ 0.2

- term. 5 + 6 solenoid valves 0.5 A, cos ϕ 0.4

- term. 7 alarm indicator 0.5 A, cos ϕ 0.4

- term. 4 auxiliary blower 2.0 A, cos ϕ 0.4
total load 4.0 A, cos ϕ 0.4

Reset time from lock out none

Re-cycling / repetition (max. 4x) after a loss-of-flame during
operation

Sensitivity 1 µA
min. ionisation current required 1.5 µA
Sensitivity for stray light 0.4 µA
Ionisation probe insulation probe - earth

Stray capacitance probe- earth

max. cable length < 3 m
Flame detectors

IRD 1020.1 side-on or end-on viewing

UVD 971 end-on viewing
Weight incl. Wiring base 190 g
Mounting position any
Protection class IP 40
Approved ambient parameter
for control and flame detector max. 95% at 30° C

- for operation -20° C... +60° C

- for storage -20° C... +80° C
Build-up of ice, penetration of
water and condensing water are inadmissible
Approvals according
to European standards EN 298 and EN 230, as

Classified acc. to EN 298 ATLLXN

50 Hz (±5%)

60 Hz (±5%)

max. 16 A during 0,5 sec

greater than 50 MΩ

less then 1000 pF

well as all other relevant
Directives and standards

Table of timings (sec.)

Model waiting time start pre-ignition time Stray light monitoring safety time post-ignition time delay 2nd-stage

05 12 3 5 5 4 25
10 12 3 5 10 9 25

EN1C-0127SZ20 R0305

tw tvz tf ts tn tv2

1

APPLICATION FEATURES

1.2 Lock-out diagnoses

1. Information system

The information system is microprocessor based and re­ports on all aspects of burner control box operation and
flame supervision. It informs continuously about the actual
programming sequence the unit is just performing. Besides
monitoring of the programming sequence it also allows to
identify errors during start-up of operation without any
additional testing devices. The automatically performed
diagnosis is a valuable tool which facilitates service/
maintenance work and therefore saves costs. The analyses
of the error cause can be done directly on stage or if not
possible afterwards as the lock out reason is stored in a non­volatile lock out mode memory.
The information system communicates with the outside
world using a LED (the used Flash-Code is similar to the
Morse-Code). The messages are optically transmitted by a
appropriately flashing LED. Using an additional terminal
(optional), the messages can be recorded and displayed in
easy readable form.

1.1 Programming sequence display

The built-in microprocessor controls not only the pro­gramming sequence but the information system too. The
individual phases of the programming sequence are
displayed as Flash-Code.
The following messages can be distinguished:

In case of a failure the LED is permanently illuminated. Every
10 seconds the illumination is interrupted by a flash code,
which indicates the cause of the error. Therefore the following
sequence is performed which is repeated as long as the unit
is not reset.

Sequence:

illuminated phase dark phase Flash-Code dark phase

❘ ❚ ❚ ❚ ❚

for 10 sec for 0.6 sec for 1.2 sec

Error diagnosis
Error message Flash-Code Possible fault
lockout ❘ ❚ ❚ ❚ ❚ within lock out safety time

no flame establishment

stray light ❘ ❘ ❚ ❚ ❚ stray light

during monitored phase,
detector may be faulty

Flash-Code for manual lock out
manual/external ❘ ❘ ❚ ❚ ❚ ❚ ❚ ❚ ❚ ❚

lock out
(see also 3. lock out and reset)

2. Flame detection

Message Flash-Code
waiting time ❘ ❘ ❘ .

tw
pre-ignition ❘ ❘ ❘ ❘ .

tvz
safety time ts ❚ ❘ .

post ignition tn
delay time to valve V2 ❚ ❘ ❘ .

tv2
running ❘ _

low mains voltage ❘ ❚ ❚ _
Internal fuse defect ❘ ❚ _

> control box defect

Description

❘ = short pulse
❚ = long pulse

. = short pause
_ = long pause

The following types of flame detectors are suitable:

– Ionisation probe, temperature resistant material, well

insulated (material and insulation same as for ignition
electrode).

– Infrared-flicker detector type IRD 1020.1 with mounting

flange M 93 or the UV solid state flame sensor UVD 971.
Flame detection using an ionisation probe is only possible
in conjunction with mains supplies which provides a neu­tral earth connection.
Connecting the IRD 1020.1 or UVD 971 the correct wiring
has to be observed.

2.1 Stray light monitoring

The stray light check is performed at the end of the pre­purge time for thr duration as mentioned in the table of
timings.

DKG 972

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3. Lock out and reset

6. Mounting and electrical wiring

The unit can be reset or brought into lock out mode in two
different ways:

Internal
In the lock out case the unit can be reset by pushing the built­in button meaning a new start-up cycle is performed.

External
Instead of using the built-in lock out button the same
function can be achieved by using an external button which
connects terminal 9 with A (see also circuit and block
diagram).

If the pushputton (internal or external) is pressed during
normal operation or during the start sequence for more then
3 sec. and afterwards released, the control box will perform
a shutdown.

Please note
The unit can only be brought to lockout mode or
be reseted if power is applied to the unit.

4. Low-voltage protection

at 220 / 240V (110 / 120V) nominal voltage

The mains voltage has to be more than 187 V
order to allow the unit to perform a start-up.

(94 V

eff

eff

) in

The mains voltage is not only monitored in the start-up
phase but also permanently during operation. If the voltage
drops below < 160 V
the control box proceed to safety shut-down and goes into

(80 V

eff

) during start-up or run time

eff

a waiting status. If the voltage rises again, the control box
performs automatically a start-up as soon as the mains
voltage is > 187 V

(94 V

eff

) .

eff

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 (wiring base S98

12-pin)
– 2 slide-in plates and 2 easy knock out holes plus 2 knock

out holes in the base bottom faciliate the base wiring

Please note
To assist trouble-free operation the main neutral
connection terminal 8 in the wiring base must be
fully tightened. The terminal screws are already in
the undone position. To connect a wire to the
terminal, the screw only needs to be fastened.

General: The control box and detector probes should not be
subjected to excessive vibration.

5. Safety

The design and control sequence of the DKG 972 controls
will comply with the currently applicable standards and
regulations (see also TECHNICAL DATA).

DKG 972

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