Krom Schroder ZAI, ZMI, ZKIH Operating Instructions Manual

03250560

F

NL

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Edition 12.11

D GB F NL I E

TR CZ PL RUS H

DK S N P GR

➔ www.docuthek.com

Operating instructions
Ionization pilot burners

ZAI, ZMI, ZKIH

Translation from the German
© 2011 Elster GmbH

Contents

Checking the usage . . . . . . . . . . . . . . . . . . . . . 2

Setting the gas type . . . . . . . . . . . . . . . . . . . . . 3

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Tightness test. . . . . . . . . . . . . . . . . . . . . . . . . . 6

Commissioning. . . . . . . . . . . . . . . . . . . . . . . . . 7

Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Replacing the electrodes . . . . . . . . . . . . . . . . . . 8

Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Technical data. . . . . . . . . . . . . . . . . . . . . . . . . 11

Declaration of Incorporation. . . . . . . . . . . . . 12

Safety

Please read and keep in a safe place

Please read through these instructions
carefully before installing or operating. Following the
installation, pass the instructions on to the opera­tor. This unit must be installed and commissioned
in accordance with the regulations in force. These
instructions can also be found at www.docuthek.com.

Explanation of symbols

• , 1 , 2 , 3 ... = Action

 = Instruction

Liability

We will not be held liable for damages resulting
from non-observance of the instructions and non­compliant use.

Safety instructions

Information that is relevant for safety is indicated in
the instructions as follows:

DANGER

Indicates potentially fatal situations.

WARNING

Indicates possible danger to life and limb.

CAUTION

Indicates possible material damage.

All interventions may only be carried out by qualified
gas technicians. Electrical interventions may only be
carried out by qualified electricians.

Conversion, spare parts

All technical changes are prohibited. Only use OEM
spare parts.

Transport

On receipt of the product, check that the delivery is
complete (see Part designations). Report any trans­port damage immediately.

Storage

Store the product in a dry place. Ambient tempera­ture: see Technical data.

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Checking the usage

Intended use

Ionization-controlled pilot burners for safely igniting
gas burners. The capacity of the pilot burner should
be 2 to 5% of that of the main burner.
Can also be used as independently operated burners.
For natural gas, town gas, coke oven gas and LPG.
Other types of gas on request.

This function is only guaranteed when used within the

specified limits – see also page11 (Technical data). Any
other use is considered as non-compliant.

ZMI

Type code

ZMI

Ionization pilot burner with forced air

supply and one electrode
16 – 25 Burner size
T T-product

B
D
G

For natural gas

For town gas, coke oven gas

For LPG
150 – 1000 Flame tube length

R Rp internal thread
N NPT internal thread

ZAI

GB

Type code

ZAI

Thermo ionization pilot burner with two

electrodes
K Double-cone olive for 8mm tube
TN 1/4" NPT internal thread

Part designations

3

2

10

4

1

6

5

7

8

9

1 Interference-suppressed adapter for ignition

electrode

2 Adapter for ionization electrode
3 Ionization electrode
4 Ignition electrode
5 Air slide valve
6 Gas connection
7 0.7 mm gas nozzle for LPG
8 Cone olive (only for ZAI K)
9 Cap screw (only for ZAI K)

10

Enclosed documentation: operating instructions

Gas connection– see type label.

D-Osnabrück
Germany

ZAI K

Part designations

3

1

2

4

7

5

1 Burner housing
2 Interference-suppressed electrode adapter
3 Air nozzle
4 Gas nozzle
5 Mounting device
6 Flame tube
7 Enclosed documentation: operating

instructions and flow rate curves

Burner size, gas type, rated capacity P
tube length, connection– see type label.

D-49018 Osnabrück Germany

ZMI
Gas

Pmax.

max.

6

, flame

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ZKIH

2 3

1

0.7

2

2 3

1

Gasdüse ∅ 0,7 mm (0,028") für
Flüssiggas.

Gasdüse für Stadtgas ∅ 1,8 mm
(0,07") separat bestellen
(Best.-Nr. 74472880).

Gas nozzle Ø 0.7 mm (0.028")
for LPG.

Order gas nozzle for town gas Ø

1.8 mm (0.07") separately
(Order No. 74472880).

Type code

ZKIH Ionization pilot burner with forced air

supply

150 – 1000

Burner tube length

/100 Flame tube length

R Rp internal thread

Part designations

Setting the gas type

ZAI

 Pilot burners ZAI are set for natural gas on de-

livery.

 If the pilot burner is to be used with a different

type of gas, retrofit the burner for its use.

1

2

4

1 Burner housing

3

a

5

b

6

0.7

Gas nozzle Ø 0.7 mm (0.028")
for LPG.

GB

Order gas nozzle for town gas Ø

2

4

1.8 mm (0.07") separately
(Order No. 74472880).

5

6

2 Burner housing cover
3 Burner tube set, comprising protective tubea

and flame tubeb

4 Retaining screw for nozzle insert (in burner

housing)

5 Nozzle insert (in burner housing)
6 Enclosed documentation: operating

instructions and flow rate curves

Rated capacity P

D-49018 Osnabrück Germany

ZKIH

Gas
Pmax.

, gas type– see type label.

max.

ZMI
1 Check if the nozzle diameter is suitable for the

2

required gas type.

 When changing the nozzle, remove the residue

of sealant from the burner housing.

 Suitable nozzles– see page10 (Accessories).

1

Nozzle dia.

Gas type

[mm (inch)]

ZMI 16 ZMI 25

B 0.94 (0.037) 1.40 (0.055)
G 0.76 (0.029) 1.05 (0.041)
D 1.30 (0.051) 1.78 (0.070)

ZKIH



Pilot burners ZKIH are set for natural gas on
delivery.

 If the pilot burner is to be used with a different

type of gas, retrofit the burner for its use.

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1

1

2

I

Z

3

1

burner using the

Installation

DANGER

Risk of explosion! Ensure the connection is gas-

tight.

 Install the pilot burner so that reliable ignition of

2

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I

3

Z

4

=

+

+

Natural gas

=

LPG

=

Town gas

5

6

the main burner is guaranteed.

 Attach the pilot burner securely.


We recommend that a filter be installed in the
gas and air supply line respectively.

ZAI

 Inlet pressure:

natural gas: max. 35 mbar (14"WC),

town gas: max. 30 mbar (12"WC),
LPG: max. 60 mbar (23 "WC).



In the case of higher inlet pressures, insert a gas
restrictor orifice.

 Ensure air intake is not obstructed.
 The ZAI has bare electrodes and no protective

flame tube. Protective tube, see page10 (Acces­sories).

WARNING

Risk of injury! Observe the projecting ionization

electrode.

Attach the

two holes on
the fastening
lug.

7

For operation with town gas, screw the retaining



8

screw back in without the nozzle insert– do not
store the nozzle insert in the connection box:
danger of short-circuits.

9 After conversion to another type of gas, adjust

the air volume– see page7 (Commissioning).

8

≈ 2 mm

9



When tightening the cap screw 9, ensure that
the cone olive 8 is correctly positioned– lubricate
the cone olive.

 ZAI flow rate curve– see www.docuthek.com

ZMI

 Recommended inlet pressures:

gas: 50 – 60 mbar (19.7 – 23.6 "WC),
air: 50 – 60 mbar (19.7 – 23.6 "WC).

 Install pressure regulators and adjusting cocks

in the air and gas supply lines upstream of the
burner so that the air and gas pressures can
be adjusted.

CAUTION

Burner fault! If used as pilot burner, the gas and

air pressures must be higher that the connection
pressures of the main burner.

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2

Connect the
pilot gas line
with 8 mm
tube.

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1

5

4

1

3

2

1

Remove the
transport safety
device.

2

2

Burner

ZMI G½"
ZMI..T

Size

16

25

G1"

½" NPT 1" NPT

3

3

4 Connect the pilot gas line with Rp¼ and the air

line with Rp½.

GB

 For connecting pilot gas and air lines with NPT

thread, order the adapter set– see page10 (Ac­cessories).

4

Position the
burner before
tightening the
cap screw.

Wiring

DANGER

Electric shocks can be fatal! Before working on
possible live components, ensure the unit is discon­nected from the power supply.



To tighten the

union nut, use
a lubricant.

For the ionization and ignition cables, use
unscreened high-voltage cable:

FZLSi 1/7 -50 to 180°C

(-58 to 356°F),
Order No. 04250410,
or
FZLK 1/7 -5 to 80°C

6 Hand tighten the union nut, mark a position for

gas-tight installation and then tighten with a fur­ther turn (360°).

7 Connect the pilot gas line with Rp¼ and the air

line with Rp½.

ZKIH

Inlet pressure:

Gas

[mbar ("WC)]
Natural gas 20 (8)
Town gas 17 (6.8)
LPG 30 (12)

 Flow rate curves– see www.docuthek.com


In the case of higher gas pressures, insert a
gas restrictor orifice– see page10 (Accessories).

(23 to 176°F),
Order No. 04250409.



Wire the burner as shown in the connection
diagrams of the automatic burner control unit/
ignition transformer.

ZAI

1

I = Ionization

I

electrode

Z

Z = Ignition
electrode

2

3

Screw for
PEwire

1

4 Connect the PE wire for burner ground to the

fastening lug on the burner insert.

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ZMI

2 31

2 31

4

1

 Flame control with single-electrode operation.

1 2 3

4 Route the PE wire directly to the automatic burner

control unit.

ZKIH

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Tightness test

DANGER

Risk of explosion and poisoning! To ensure that

there is no danger resulting from a leak, check the
gas connections on the burner for leaks immediately
after the burner has been put into operation.

ZAI

1

2

4

5

I

Tighten the PGcable gland.

I = Ionization electrode
Z = Ignition electrode

Z

= Screw for PEwire

6 Tighten ionization and ignition cables securely.

WARNING

Electric shocks can be fatal! Live components

in the housing connection chamber.

7 Replace seal and cover and screw into place.
8 Connect the PE wire for burner ground to the

burner.

ZMI

2

ZKIH

1

2

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Commissioning

5

6

5

6

5 6

DANGER

Risk of explosion! Please observe the appropriate

precautions when igniting the burners.
Risk of poisoning! Open the gas and air supply
so that the burner is always operated with excess
air – otherwise CO will form in the furnace chamber.
CO is odourless and poisonous! Conduct a flue
gas analysis.
ZKIH: electric shocks can be fatal! The burner
housing cover must be fitted before igniting the
burner.

 Arrange the adjustment and commissioning of

the burner with the system operator or manu­facturer.



Check the entire system, upstream devices and
electrical connections.



Pre-purge the furnace chamber with air (5 x
furnace chamber volume) before every ignition
attempt.



Fill the gas line to the burner carefully and cor­rectly with gas and vent it safely into the open
air – do not discharge the test volume into the
furnace chamber. Risk of explosion!

 If the burner does not ignite although the auto-

matic burner control unit has been switched on
and off several times: check the entire system.

 After ignition, monitor the gas and air pressures

measured on the burner and the flame. Measure
the ionization current. Switch-off threshold– see
automatic burner control unit operating instruc­tions.

1 Switch on the system.
2 Open the manual valve.
3 Ignite the burner via the automatic burner control

unit.

4 Adjust the burner.



Set the ionization current by adjusting the air
volume.

DANGER

Risk of explosion in case of CO being formed
in the furnace chamber! An incorrect change of

the burner settings may change the gas/air ratio
and lead to unsafe operating conditions. CO is
odourless and poisonous!

ZAI

The air slide is open on deliv-

ery. Only close the air slide if

the burner flame is not stable.

ZMI
5 Set the pressure regulators for the gas and air

supply pressures to the maximum admissible
values, whereby the gas and air supply pressures
should be identical.

0

Adjust the burn­er pressures for
gas and air on
the adjusting
cocks upstream
of the ZMI.

p

Gas

0



The air inlet pressure must always be higher than

p

Air

the gas inlet pressure: operating characteristic
diagrams– see www.docuthek.com.

 Inlet pressure:

gas: 20 – 50 mbar (8 – 20"WC),
air: 20 – 50 mbar (8 – 20 "WC).

ZKIH



Inlet pressure for air adjustment screw set at
the factory:

Gas

[mbar ("WC)]

Air

[mbar ("WC)]
Natural gas 20 (8) 20 (8)
Town gas 17 (6.8) 35 (13.8)
LPG 30 (12) 30 (12)

 If the air inlet pressure cannot be set to the rec-

ommended value owing to the factory setting of
the air adjustment screw, readjust the air adjust­ment screw.

7

Turn the air adjustment screw

to the left to increase the air

I

Z

flow. Turn the air adjustment
screw to the right to reduce
the air flow.

8 Replace seal and cover and screw into place.

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Maintenance

7

6

7

8

6

76

7

 We recommend an annual function check.

DANGER

Electric shocks can be fatal! Before working

on possible live components, ensure the unit is
disconnected from the power supply.
Risk of burning! Dismantled burner components
can be hot due to outflowing flue gases.

Risk of explosion and poisoning during burner
adjustment with an air deficiency! Adjust the

gas and air supply so that the burner is always oper­ated with excess air – otherwise CO will form in the

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furnace chamber. CO is odourless and poisonous!
Conduct a flue gas analysis.

1 Check the ionization and ignition cables.
2 Measure the ionization current.

 The ionization current must be at least 5µA and

must not vary.

9

For correct positioning, slide
in the electrodes until the
projection of the retaining plate
engages into the groove.

When slid­ing in the
electrodes,
ensure they
are aligned.

10 Once the electrodes have been positioned, hand

tighten the retaining plate screw using a spanner
(approx. 3turns).



After tightening, the electrodes cannot be moved
any more.

ZMI

Z

+ μA –

I

3 Disconnect the system from the electrical power

supply.

4 Shut off the gas and air supply – do not change

the restrictor settings.

5 Check the nozzles for dirt.

Replacing the electrodes

ZAI

8

Loosen the
screw of the
retaining plate
by turning
it approx.
3turns.

Groove for
correct posi­tioning of the

electrode.

ZMI 16



Ensure that the electrode length does not change.

2

1

ZMI 25

3

L

5

4

1 Spark plug
2 Dowel pin
3 Insulators
4 Burner head
4 Electrode tip

8 Remove dirt from electrodes and insulators.
9 If the electrode tip or insulators are damaged,

replace the electrode.



Before changing the electrode, measure the
total length L.

10 Connect the new electrode with the spark plug

using the dowel pin.

11 Adjust spark plug and electrode to the measured

total length L.

12 Screw the electrode into the burner housing.
13 Check distance L2:

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10

22 mm

2 mm

14

12

13

1

2

1

2

Burner L2
ZMI 16B 25 mm
ZMI 16D 21 mm
ZMI 16G 25 mm

L1

Burner L2
ZMI 25B 35 mm
ZMI 25D 20 mm
ZMI 25G 35 mm

L2

12

13

1

22 mm

Align the ignition electrode1

2

and the ionization electrode2.

Adjust the spacing of the

electrode tips.

2

ZKIH

6 Undo the housing cover screws, remove seal

and housing cover.

7 Unscrew the ionization and ignition cables.

14

2 mm

1

Slide the rear guide lug as far

GB

as it will go in the direction

WARNING

High-voltage risk! Live components in the housing

of the burner housing. Hand
tighten the screw.

connection chamber.

8 Unscrew the PE wire for burner ground from the

burner.

9 Remove the burner– see page4 (Installation).

15

Align the insulators.

 Removal and reassembly of the electrodes is fa-

cilitated, when the housing is placed in a vertical
position on a smooth working surface.

6 mm

Loosen the
screws ½a
turn.

16

Slide the front guide lugs as far
as they will go in the direc­tion of the burner head. Hand

11

2

2

1

1

Replace the
electrodes
one after the
other.

17

tighten the screw.

For longer burners, slide the
other guide lugs against the
retaining plate. Hand tighten
the screw.

ZAI, ZMI, ZKIH

• Reconnect the electrode adapters.

• Produce a maintenance report.

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Accessories

1

Protective tube set

 For ZAI, heat-resistant.

35437010

2

Adapter set



For connecting the pilot burner ZKIH to pilot

gas and air lines. Comprising one adapter with
1/4-18 NPT internal thread and one adapter with
1/2-14 NPT internal thread.

1

74923430

GB

Gas nozzle

For ZAI:

 1.8 mm.
 For operation with town gas.

Order No. 74472880

For ZMI and ZMI..T:

Gas

Burner

type*

ZMI 16

ZMI 25

* B = Natural gas
G = LPG

mm

(inch)

0.94

B

(0.037)

0.76

G

(0.029)

1.30

D

(0.051)

1.40

B

(0.055)

1.05

G

(0.041)

1.78

D

(0.070)

D = Town gas/coke oven gas

Order No.

ZMI ZMI..T

75455010 75442157

75455147 75448032

75455146 –

75455012 75443157

75455149 75448031

75455148 –

Gas restrictor orifice

 Rp 1/4".
 For operation of the ZKIH at the following inlet

pressures:

Inlet pressure in mbar

Natural

gas

Propane

Town

– – 20–50

23–50 – 50–200

50–120 –

200–1500

120–450 50–200 –

450–1500

200–1500

gas

–

Hole mmOrder

No.

2.3

74452740

1.5

74452742

1.2

74452744

0.9

74452745

0.6

74452747

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Technical data

ZAI

Capacity: approx. 1.8 – 3 kW.
Gas types: natural gas, LPG (gaseous) and coke
oven gas.
Gas inlet pressure: 20 – 60 mbar (8 – 24"WC),
depending on the gas type.
Condition on delivery: for natural gas, max.
30mbar (12"WC),
(gas inlet pressures– see www.docuthek.com,
Kind of document: Flow rate curve).
Flame control: with ionization electrode.
Ignition: direct spark ignition (5 kV ignition trans­former).
Ignition electrode adapter: interference-sup­pressed.
Ignition head made of galvanized steel.
Retaining plate made of galvanized steel.

ZMI

Capacity:
ZMI 16: 0,8 to 2 kW,
ZMI 25: 2.5 to 4 kW (1.5 to 3.3kW when used
with town gas, coke oven gas).
Gas inlet pressure: 15 to 70 mbar (6 to 27"WC).
Air inlet pressure: 15 to 90 mbar (6 to 35"WC),
each depending on the gas type
(burner pressures – seewww.docuthek.com, Kind
of document: Flow rate curve).
Burner length increments: 100 mm.
Gas types: natural gas, LPG (gaseous) and coke
oven gas; other gases on request.
For cold air only.
Flame control: with ionization electrode.
Ignition: direct spark ignition (5 kV ignition trans­former).
Ignition electrode adapter: interference­suppressed.
Housing: AlSi.
Flame tube: heat-resistant steel.

Max. temperature at the tip of the flame tube:
<1000°C (< 1832°F),
< 900°C (< 1652°F) for lambda <1.

ZKIH

Capacity: approx. 2 to 5kW.
Gas types: natural gas, LPG (gaseous) and coke
oven gas.
Gas inlet pressure: 5 to approx. 50mbar (2 to
approx. 20"WC),
air inlet pressure: 5 to approx. 30 mbar (2 to ap­prox. 12"WC),
each depending on the gas type
(burner pressures– see www.docuthek.com, Kind
of document: Flow rate curve).
On delivery: natural gas setting (gas and air pres­sures: 20 mbar (8 "WC)).
For cold air only.
Flame control: with ionization electrode.
Ignition: direct spark ignition (5 kV ignition trans­former).
Housing: AlSi.
Protective tube: stainless steel.
Flame tube: heat-resistant steel.

Max. temperature at the tip of the flame tube:
<1000°C (< 1832°F),
< 900°C (< 1652°F) for lambda <1.

Max. temperature of the protective tube: 500°C

(932°F).

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Declaration of Incorporation

pursuant to 2006/42/EC, Annex II, No. 1B

The products “Burners for gas ZAI, ZMI and ZKIH”

are partly completed machines pursuant to Article2g
which are designed exclusively for installation in or
assembly with another machine or other equipment.

The following essential health and safety requirements

pursuant to Annex I of this Directive have been ap­plied and satisfied:
Annex I, Articles 1.1.3, 1.1.5, 1.3.2, 1.5.1, 1.5.2, 1.5.7

The special technical documentation pursuant to

AnnexVIIB has been produced and will be transmit­ted to the competent national authorities in electronic

GB

form on request.
Furthermore, the partly completed machine complies
with all the provisions of the following Directives:

– Electro magnetic Com pa tibility Directive

(2004/108/EC)

The following (harmonized) standards have been

applied:

– EN 746-2 (2010) – Industrial thermoprocessing

equipment – Safety requirements for combustion

and fuel handling systems

– EN ISO 14121-1 (2007) – Safety of machinery.

Risk assessment. Principles.

– EN 12100 (2003) – Safety of machinery– Basic

concepts, general principles for design
Part 1: Basic terminology, methodology
Part 2: Technical principles

The partly completed machine may only be put into

service once it has been established that the machine
where the product mentioned above is to be installed
complies with the provisions of the Machinery Direc­tive (2006/42/EC).
Elster GmbH, Osnabrück

Contact

If you have any technical questions, please contact
your local branch office/agent. The addresses are
available on the Internet or from ElsterGmbH.

We reserve the right to make technical modifications
in the interests of progress. [e-mail], www.kromschroeder.com

Elster GmbH
Postfach 28 09, D-49018 Osnabrück
Strotheweg 1, D-49504 Lotte (Büren)

T [phone]

F [phone]

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