Doc No. 700070 Page 37 of 56
4. Tighten grub screw (A) to secure damper position.
3.6.16 Repeat procedure 3.6.14 for any further
branches (where necessary), moving closer to the fan as
each branch is completed. The vacuum setting procedure is
now complete.
3.7
ABB Inverter Driven BH300 Fan,
Modulating Branch Damper (Zonal
modulation)
In this method, the fan is driven by the inverter and
adjusted to give the correct output for full fire.
Modulation is achieved by adjusting each branch damper
via a 0-10Vdc input to the damper motor via an external
control.
3.7.1 Ensure that electrical supplies to the end vent modules
and burners in each branch are connected.
3.7.2 Check that the fan and branch dampers are fully open
and secure.
3.7.3 Ensure the controller is in a programmed ON function
and above the actual room temperature.
3.7.4 After a 30s delay the fan should run and the inverter
should be showing the motor frequency in the display.
3.7.5 Set the maximum motor speed parameter 2008 to a
value where all the burners light.
Frequency is usually between 35 and 50 (Hz)
3.7.6 Press the ‘ ‘ button to return the inverter to the
normal display.
3.7.7 Remove heat demand to the system and allow fan to
halt.
3.7. Return power to system. After a 30s delay the fan should
run and a red neon should have illuminated on the rear of
each burner.
3.7.6 If the dip-switches have been set correctly, the burner
closest to the manifold (last on branch) should ignite first
followed in order by every burner towards the end vent
burner.
Note: It may be necessary to temporarily break the union at
a burner in order to purge the gas pipe of air.
FOLLOW INSTRUCTIONS ON P39 (3.8) FROM THIS POINT
