Connecting The Gas Supply; Connecting The Oil Supply; Connecting The Water System - Potterton NXR4 Installation, Operation & Maintenance Manual

SECTION 4
PAGE 24
Volt Free Contacts
Volt free connection should be taken from the control
panel where a 24V signal is provided, see Section 6
for further details.

CONNECTING THE GAS SUPPLY

The connection should be made to the burner
connection (see burner card enclosed with this
manual for size required). A union and isolating valve
should be fitted close to the burner to allow
disconnection of the burner for maintenance and
repair.
The gas supply should be made through a suitable
meter and the local gas undertaking should be
consulted to determine the suitability of the meter and
gas supply to meet existing and additional demands
for gas.
The installation should be made in accordance with
the requirements of the Gas Safety (Installation &
Use) regulations and all other regulations and codes
of practice.
In particular a manual valve for isolation of the boiler
house shall be fitted in an accessible position and
readily identifiable.
The gas supply should be supported adequately.
For large single
consideration should be given to the installation of
additional gas meters to assist in the monitoring of
boiler performance.
Attention is drawn to the need for adequately sized
pipework according to the maximum gas demand for
multiple boiler installations and each boiler shall be
provided with an isolating valve so that it is possible to
isolate the boiler from a common gas supply for
maintenance purposes.
Boosters are required if the inlet pressure under full
load is less than that recommended by the burner
manufacturer (see burner card for details).
If a booster is required, the local gas undertaking must
be consulted and the booster shall be fitted with a low
pressure cut off switch upstream of the booster in the
event of reduced pressure and to prevent automatic
restart on pressure restoration. The cut off pressure
shall be decided by the local gas undertaking.

CONNECTING THE OIL SUPPLY

FUEL STORAGE AND HANDLING – The provisions
of BS2869 will normally ensure that the fuel will be of
adequate performance. There are winter and summer
fuel grades and in order to prevent the fuel waxing
POTTERTON COMMERCIAL PRODUCTS DIVISION
INSTALLATION, OPERATION & MAINTENANCE MANUAL
and multiple installations
under sustained cold and exposed conditions, Class D
grade fuel oil should be stored and supplied to the
burner at a minimum temperature of 5°C, in line with
the fuel supplier's recommendations to suit site
conditions.
The supply pipe and, where fitted, the return line
should consist of copper tube (galvanised steel must
not be used), the final connection to the pump inlet
port being made with the length of flexible pipe
supplied with the burner. Joint should be made with
compression fittings, not by soldering.
When gravity feed is used (the most common system)
the maximum head should not exceed 4m (equivalent
to a pressure of 35 kPa).
PUMP BLEEDING – If the fuel tank is allowed to drain
completely it will be necessary to bleed the oil pump
free of air by slackening the plug in the pressure
gauge port allowing oil to run through until air free.
OIL FILTRATION – SEDIMENT REMOVAL – There
is an oil strainer inside the body of the fuel pump and
a separate oil filter between the oil pipe from the tank
and the oil burner. The oil strainer should be removed
and cleaned with paraffin during the pre-season
check-up. At the same time the oil filter cartridge
should be replaced or cleaned, as appropriate for the
type fitted. Bleed fuel pump free of air, as described
previous, to remove any trapped air.
Draw off any accumulation of water or sediment in the
fuel tank by opening the sludge cock in the tank
bottom, immediately before any new delivery of fuel.
Do not run the burner while the tank is being refilled
and, if possible, do not restart for one hour after
refilling is concluded.

CONNECTING THE WATER SYSTEM

The flow and return connections should be made to
the appropriate manifolds,
recommendations of CP342 and PM5.
It is essential that all pipework connections to the
boiler are self-supporting, correctly aligned and
allow for free expansion of both boiler and
pipework.
Care should be taken in the pipework design to
prevent strain on the connections. Excessive
strain can lead to premature failure of the boiler,
which is obviously outside the terms of our
warranty.
The use of expansion bellows to take up both
axial and lateral movement is recommended.
NXR4
following the