2.
Pressure-controlled regulation of
exodraft
chimney fan
2.1
Use
Area of use
• The EBC20 is designed for use with boiler systems with 1- and 2-stage burners.
• The EBC20 can also be used for boiler systems with modulating burners.
• The EBC20 can also be used for multiple boiler systems.
• The control system is intended for:
solid fuel boilers
atmospheric gas boilers
forced draft boilers for oil and gas
condensing boilers
• The EBC20 can control a chimney fan directly or indirectly via a frequency converter.
2.2
Method of operation
General function
• The control system monitors chimney draft and disconnects the burner in the event of errors (the alarm-
diode on the EBC20 will turn on).
• When the boiler thermostat demands heat, the chimney fan will start at max. voltage, the burner start is
delayed.
• When the EBC20 registers sufficient chimney draft, the burner is released.
• The EBC20 maintains the set pressure by regulating the voltage. The pressure is shown in the display.
• In the event of an insufficient pressure the burner will be disconnected after 15 seconds. “Insufficient pres-
sure” is less than 64% of the set value, corresponding less than 80% flow.
• When the boiler switches off, the chimney fan is also stopped. However, it is possible to set a post-purge
period for the chimney fan (see page 23). Alternatively, the control system can be set up to keep the
chimney fan running continuously (see page 21).
Light emitting diodes and output signals
All inputs and outputs are linked to light emitting diodes for the monitoring and service of the system (1.4.2 Light
emitting diodes and terminal board, page 8 ).
The EBC20 has 0–10V output signals for controlling multiple chimney fans via frequency converters or motor power
relays.
2.3
Electrical connection
This work must be performed by a qualified electrical engineer, in accordance with locally applicable rules and
legislation.
The installation of the supply cable must be carried out in accordance with applicable regulations and
legislation.
The earth terminal (
) must always be connected.
When connecting pressure transducer (XTP) and frequency converter, shielded cable must be used.
Isolation switch
exodraft
stresses that according to EU’s Machinery Directive an isolation switch must be set up in the fixed
installation.
The isolation switch is not supplied by
exodraft
. Available as an extra.
2.4
Sample wiring diagrams
As a constant pressure regulator for
exodraft
chimney fans, the EBC20 can be connected to a range of different signals.
The following pages are sample wiring diagrams, and show the following:
• 2.4.1 Single- or two boiler application, page 17
• 2.4.2 Single boiler application with potential free contact in boiler, page 18
• 2.4.3 Single boiler application with extra fail-safe protection using PDS, page 19
• 2.4.4 Single boiler application with a frequency converter, page 20
• 2.4.5 2 boiler application with continuous operation of chimney fan, page 21
• 2.4.6 Solid fuel boiler with temperature sensor, page 22
exodraft
recommends that you contact the boiler manufacturer for details of correct connection of the boiler
control system.
3002878-EBC20-UK
16
• Pressure control
