Ozroll OZS251E, Руководство по установке

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F3. TANK ANODES
TWO cast magnesium sacrificial anodes are connected to the inside of a storage tank from the top of the tank.
Magnesium is used because it is a more active metal than steel. The magnesium rod therefore acts as an anode,
by supplying electrons, and therefore sacrificing itself to protect the steel from corrosion. Therefore, over time,
the Magnesium anode corrodes and requires replacement.
STORAGE TANK P/N ANODE 1 ANODE 2
31.100.100 680mm 1045 mm
31.100.101 680mm 1275mm
31.100.102 680mm 1315mm
F4. ANODE REPLACEMENT
Replacement of the anode should be carried out at every few years. As a guide, the more dissolved solids in the
water, the faster the anode corrodes and the shorter the intervals should be between replacement. If the Total
Dissolved Solids (TDS, ppm) is > 1000, recommended anode replacement should be at 5 years. If the Total
Dissolved Solids (TDS, ppm) is < 1000 then replacement should be at 7 years.
F5. TANKS – HOW DO THEY WORK ?
Water is stored at MAINS PRESSURE which varies depending on the location of the installation. A minimum of
500 kPa cold water pressure is required otherwise mains pressure performance cannot be expected.
Cold water enters at the bottom of the tank, is stored until required. Hot water is drawn off from the top of the
tank. As this happens, more cold water enters to replace it. A non-return valve in the mains cold water connec-
tion prevents water returning to the mains water supply. To prevent damage to the cylinder, storage water heat-
ers are fitted with a combination Temperature Pressure Relief (TPR) valve mounted at the top of the cylinder.
The relief pressure of the valve is the maximum pressure the heater is designed to withstand, and is known as
the working pressure or operating pressure. If the working pressure is reached (eg due to thermal expansion),
the valve releases some water to maintain the pressure at acceptable levels.
F6. CYLINDER - POSITION
By locating the cylinder as close as possible to points of use, you can minimize heat loss and hot water wasted.
Choose a position close to the most often used tap if possible. In most cases this position would be close to the
kitchen primarily followed by the bathroom. A site midway between these rooms would be ideal. The location
should be accessible for maintenance. The cylinders should be positioned so that the rating label can be read
and parts can be removed for service.
Interior cylinders
The National Plumbing and Drainage Code AS/NZS 3500.4 requires the fitting of a safe tray under a water
heater installed indoors in a concealed position. This safe tray must be connected to a drain that falls continu-
ously to an approved termination point. It may be necessary to raise the cylinder onto a low stand. Ensure that
there is adequate floor support under the location selected. An electric-boosted cylinder will lose less heat if it
is enclosed in a cupboard, or isolated from draughts.
Exterior cylinders
It is usual to use a concrete plinth (paver) as a base for a cylinder that is mounted on the ground. For cylinders
located on sealed surfaces (bricks or concrete paths), provision must be made to accommodate the water that
escapes due to expansion through the pressure relief valve. A hole of 100mm diameter through the concrete
and filled with coarse gravel under the discharge pipe is acceptable. The plinth should be level and a minimum
of 50 mm above the ground level to prevent the water heater base being in contact with water for extended
periods.
Alternatively, Cylinders can be mounted on a plastic Polyslab base, which must be levelled correctly and fitted
in accordance with manufacturer’s instructions.
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