Doc No. 700070 Page 36 of 56
3.6 Inverter Driven Modulating Fans
( BH300 with ABB inverter)
The use of an inverter allows the end vent suction to be
adjusted by varying the output speed of the inverter within
the local relay unit. This is achieved via a 0-10Vdc input
direct to the inverter via an external control.
NOTE: Ensure the modulation input setting in the inverter
functions has been adjusted accordingly.
3.6.1 Ensure that electrical supplies to the end vent modules
and burners in each branch are connected.
3.6.2 Check that the fan and branch dampers are fully open
and secure.
3.6.3 Ensure the controller is in a programmed ON function
and set to maximum temperature. (10V dc max from the
controller).
3.6.4 After a 30s delay the fan should run and the inverter
should be showing the motor frequency in the display.
3.6.5 Set the
maximum motor speed parameter 2008 to a
Hz value where all the burners light reliably.
Frequency is usually between 35 and 50 (Hz)
3.6.6 Press the ‘ ‘ button to return the inverter to the
normal display.
3.6.7 Remove heat demand from the system and allow fan
to halt.
3.6.8 Return heat demand to system. After a 30s delay the
fan should run and a red neon should have illuminated on
the rear of each burner.
3.6.9 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.
3.6.10 Observe the ignition of ALL the burners. An amber
neon should illuminate on the rear of the burner when the
burner is lighting and remain if the burner has lit. If the
burner fails to light, the amber neon will extinguish
leaveing only the red neon illuminated.
3.6.11 When the branch has been running for 30 minutes,
check the end vent vacuum reading at the burner
Menu selection
(also save/OK ‘ ‘ and
exit ‘ ‘)
Parameter selection
FURTHEST AWAY
.
3.6.10 Re-adjust the frequency on the inverter (parameter
2008) until the high fire end vent suction is achieved (details
of which are given in table 12)
3.6.11 Remove heat demand from controller.
3.6.12 Set the minimum motor speed parameter 2007 to
adjust the frequency until the low fire end vent suction is
achieved (details of which are given in table 12).
3.6.13 Reset controller to give heat demand.
3.6.14 Proceed to the next radiant branch closer to the fan
and check the end vent vacuum reading at high and low
fire.
3.6.15 Adjust the branch damper (if necessary) located at
the end of the branch to bring the vacuum readings in line
with the normal operating figure shown in table 12. Ensure
the damper is locked securely after adjustment.
Adjustment instruction for branch damper.
1. Loosen grub screw (A).
2. Turn adjustment lever (B).
3. Position of damper blade is indicated by position of bent
adjustment lever.
