BENSON MH300, User Instructions

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2.5 Two pipe system
This is used where the oil storage tank is lower than
the pump.
Access for the fuel feed to the burner should be via
a suitable tapping made in the top of the tank, and
the fuel feed pipe should extend to not less than
100mm above the bottom of the tank.
A none return valve with a metal to metal seat
should be fitted, especially if the return pipe work is
terminated at a level above the draw off tube.
The non return valve must be removable for service
and maintenance purposes, and the return pipe from
the pump must therefore be extended down into the
tank to the same level as the suction pipe.
The presence of a tamper proof isolating valve fitted
within the return pipe is only required if there is a
risk that oil will siphon out of the tank if the return
pipe is disconnected at the pump during
maintenance or servicing and if the none return
valve has been omitted.
2.6 Pipe work and fittings
Caution
Galvanised pipe work and fittings must not be used.
All joints must be sealed properly, if necessary using
PTFE tape or other approved sealing media.
The pipe work must be effectively sealed so as to
prevent the ingress of air.
It is advisable to check all pipe work prior to
installation to ensure that there is no loose debris or
scale present.
Black iron pipes can be hammered to assist in the
removal of these contaminants.
Note
The oil feed to each heater must be fitted with a fire
check valve and isolating valve.
The fire check valve must be operated by way of a
fusible link positioned so that it is above the burner.
2.7 Oil Installation/connection
The oil tank must be positioned so that there is a fall
of 7.5mm (+/- 2.5mm) for every 30mm away from
the outlet and towards the sludge/drain valve, which
must be sited at the lowest point in the tank. If the
tank is positioned on supports then there must be an
adequate protective layer between tank and support
to prevent damage or deterioration through
corrosion
It is strongly suggested that reference is made to
BS 5410 ; part 2 ; 1978.
It is also suggested that the installer is familiar with
the detail and requirements contained within
sections 2.1 through to section 2.6 of this manual
prior to commencing installation.
Warning
Prolonged exposure and contact with Gas Oil can
result in the natural oils being removed from the
skin, sensitisation can result in dermatitis.
Always ensure that the appropriate personal
protective equipment is used
.
2.8 Electrical supply
Wiring external to the cabinet heater must be
installed in accordance with any local, national, and
European regulations, as well as meeting the
appropriate requirements of IEE regulations.
The means of connection to the main electrical
supply must allow for complete electrical isolation of
the heater, furthermore, in the case of a unit wired
for a three phase supply, the supply should only be
used to serve the heater itself and no other plant or
equipment.
Warning
Ensure that the electric and oil supplies are turned
off before any electrical work is carried out on the
heater.
Ensure that wiring cannot make contact with any
surfaces liable to be subject to high temperatures or
where the insulation of the wiring could be impaired
as a result of such contact.
All Benson cabinet heaters must be earthed .
Caution
The main electrical supply must not be switched off
or disconnected as a method for stopping the
heater, the exception to this is in an emergency, or
during servicing, when the heat exchanger has been
allowed to cool sufficiently to prevent any damage
from occurring.
Claims for damage will not be considered if they