4.
Pressure regulation of exodraft chimney fans
4.1
Application
Field of application
• EBC24 can also be used for boiler systems with modulating burners.
• The automation is designed for both solid fuel boilers, atmospheric gas boilers, and boilers with oil and
gas blow torches.
• EBC24 can control a chimney fan directly or indirectly via a frequency converter.
4.2
Functioning
General function
• The automation monitors the draft in the chimney, disabling the burner in case of malfunction (the alarm
diode on the EBC24 turns on).
• When the boiler thermostat demands heat, the chimney fan will start at max. voltage.
• When the EBC24 registers sufficient chimney draft, the burner is released.
• The EBC24 maintains the set pressure by regulating the voltage. The pressure is shown in the display.
• In the event of insufficient venting, the burner will initially be disconnected after 15 seconds. Insufficient
venting is less than 64% of the set value, corresponding to less than 80% of flow.
• When the boiler turns off, the chimney fan stops as well. It is, however, possible to set a post-purge period
for the chimney fan (see page 23). Alternatively, the control system can be connected in a way that keeps
the chimney fan running continuously (see page 21).
Light-emitting diodes and output signals
All inputs and outputs are connected to a light-emitting diode for monitoring and servicing of the system (see section
2.9.1 Light-emitting diodes and terminal board, page 17)
EBC24 has 0-10V output signals for control of multiple chimney fans via frequency converters or motor power relays.
4.3
Electrical connection
This work must be performed by a qualified electrician in accordance with locally applicable rules and
legislation.
Installation of the supply cable must comply with applicable legislation and regulations.
The grounding terminal (
) must always be connected.
When connecting a pressure transducer (XTP) and frequency converter, shielded cable must be used.
Isolation switch
exodraft a/s stresses that according to EU’s Machinery Directive, an isolation switch must be
incorporated into the fixed installation. The isolation switch is not supplied by exodraft, but is available
as an accessory.
4.4
Wiring examples
As a constant pressure regulator for exodraft chimney fans, the EBC24 can be connected to a range of different signals.
The following pages are wiring examples and illustrate the following:
• 4.4.1 One boiler, page 20
• 4.4.2 One boiler med potential free contact, page 21
• 4.4.3 One boiler and extra monitoring with PDS, page 21
• 4.4.4 One boiler connected to frequency converter, page 23
• 4.4.5 Two boilers with continuous operation of chimney fan, page 24
exodraft recommends contacting the boiler manufacturer for correct connection to the boiler
automation.
3120073-UK EBC24
Pressure control •
19
