Fabdec EXCELSIOR, Installation Manual

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Two Port Valve
The two port valve should be wired to the thermostat (see Figure 7 or 8 depending on required configuration). Connect the
live supply to the thermo cut-out and connect the brown wire of the two port valve to terminal 1 on the thermostat (see
Figure 11). Earth and Neutral supplies can be connected directly to the valve. The orange wire of the two port valve should
be connected to the central heating boiler and the cylinder thermostat set to 60°C. The power supply to the pump station
should be connected via the lower valve
Figure 11. Twin thermostat wiring
3.4 Tundish
The tundish supplied must be fitted so it is visible to the occupier. The discharge pipe must be 22mm copper pipe.
Regulations do not permit more than 3 x 90-degree bends between the Excelsior unit and the outflow. Between the
temperature & pressure relief valve and the first 90-degree bend there must be a fall of at least 300mm. The fall of the
pipework must be continuous and the pipe should terminate in the gully or be bent backwards onto an outside wall, in a
place where discharge cannot be injurious to persons.
If you need to site the Excelsior unit in the middle of the house your discharge pipe to the tundish can be as far away as
9m, which in most cases is enough to run the final discharge point. After 9m, increase the pipe size to a greater diameter
than 22mm and accordingly for subsequent 9m lengths, (see table 1).
Figure 12. Tundish Installation
IMPORTANT: REGULAR CHECKS SHOULD BE CARRIED OUT TO ENSURE THAT THE EXPANSION VESSEL IS ALWAYS
CORRECTLY PRESSURISED TO 3.5 BAR.