Page 7
Models NG125 & NG150 Revision 121199B
Gas Supply
The gas supply pipework to the burner must be
appropriate to local conditions and must be con-
structed and installed in compliance with appro-
priate Codes and Standards. It shall be of sufficient
size to satisfy the pressure and volume flow require-
ments of the burner under all firing conditions.
Checks should be made to ensure that all meters
and other components are appropriately rated for
the maximum gas flow rate anticipated.
It is essential that a 90° manual isolation valve is
fitted upstream of the gas control train to allow the
burner to be isolated for maintenance. The size of
this valve should not be less than that of the burner
control train in order to avoid any restriction in gas
flow.
Gas Boosters
When a gas booster is used the gas pressure at the
booster inlet must not fall below 10 mbar under
any conditions. A low gas pressure switch must be
fitted on the upstream side of the booster to pre-
vent it starting if the supply pressure is insufficient.
An additional pressure switch should be used to
monitor the pressure downstream of the booster
and prevent the burner going to high fire if the pres-
sure is insufficient.
The booster should be installed as near to the burner
as possible. It should be positioned on a firm, flat,
horizontal surface using anti-vibration mountings.
All connecting pipework should be well supported
and accurately positioned in order to avoid stress-
ing the booster casing. The use of flexible connec-
tors, which reduce both pipework stresses and
transmitted noise, is strongly recommended. The
gas supplier should be asked to recommend the
size of pipework between the meter and the booster
to ensure that the required pressure and flow are
available.
Electrical Power Supply
A three-phase 50 Hz supply is required. Power re-
quirements are listed in the Table on Page 8. The
power supply provided must comply with all rel-
evant Codes and Standards.
UNPACKING AND ASSEMBLY
To safeguard against damage in transit, NG burn-
ers are supplied in partly assembled form, com-
prising two units:
- The burner body, complete with control pack-
age and flame tube assembly.
- The gas control train.
To assemble the burner:
- Fit the gas control train to the burner body
using the gasket supplied, ensuring that the
gasket is fitted correctly with all holes corre-
sponding with those on the burner flange.
- Connect the air inlet/impulse pipe from the
SKP70 air/gas ratio controller to the left side
of the burner body.
- Connect the multi-pin plug on the gas valve
train to the socket on the rear of the control
package.
Note: In some circumstances it may be advisable
to fit the burner casing to the appliance before at-
taching the gas control train.
INSTALLATION
General
Ensure that the appliance is suitable for the heat
input of the burner. If there is any doubt in this
area reference shall be made to the appliance
manufacturer. Detailed burner performance data
are presented in the Appendix of this handbook.
Fitting To The Appliance
If the burner is to be fitted to a new appliance refer
to the appliance manufacturers recommendations.
If the burner is to be fitted to an existing appliance
a mounting flange must be provided as detailed in
the Section on Burner & Components Identifica-
tion. Ensure that the joint between the burner and
the mounting flange is sealed effectively using the
gasket provided.
The flame tube should not extend beyond the in-
ner face of the appliance combustion chamber
unless extensions are specified by the appliance
manufacturer, for example in the case of reverse
flame boilers.
Electrical Power Connection
Connect a three-phase, 50 Hz electrical supply to
the burner, observing all applicable Codes and
Standards. The electrical connections required are
shown on Page 8 and in the wiring diagram con-
tained in the instruction pack attached to the burner.
These diagrams also show the external auxiliary
control connections which must be made.
