Exodraft MEC24 - General; Basic Control Set-Up

5. Startup and conguration
5.1 General
When power is supplied to the control it will go through a start-up procedure to detect and check all components and
appliances installed.
5.5 Basic control set-up
Once power is turned ON the control can be programmed. Most parameters are programmed at the factory and do not
need to be changed. The most common parameters are shown below.
To enter the setup menu, press the “” key for more than 5 seconds. The password 3142 must be entered using the up and
down buttons, and after that press the “” key.
Menu 11: SET EXHAUST
For setting the draft or exhaust pressure. Although the value, when measured in the eld, is negative pressure it shows up
as a positive value on the display. The lowest possible value is 0.012 inWC. Most applications require a setting in the range
of 0.012 inWC to 0.100 inWC. Atmospheric appliances (Category I) are always in the low range, while all other appliances
can be anywhere.
The %-value indicates the relative setting of the total range of the sensor. (The [inWC] units can be changed to [Pa] in the
menu 512. )
Menu 12: EXHAUST OPERATING MODE
The control can operate the fan(s) in either ‘continuous’ or ‘intermittent’ mode. The mode can be changed via the display in
menu 12.
Note! Continuous mode only works if Priority mode is “o” (menu 451)
In ‘continuous’ mode the fan operates continuously. During times when the heating appliance(s) is not operating, the fan
will still operate although at its lowest capacity. Some exhaust will be pulled through the appliance. The chimney is always
primed and there is no real need for pre- and post-purge functions. The energy consumption in this mode is minimal.
In ‘intermittent’ mode the fan only operates if at least one appliance is operating. When no appliance(s) is operating the
fan shuts down. In this mode, pre- and post-purge functions are very important and must be set. This mode oers the low-
est energy consumption.
If a heating system operates constantly, or the time between cycles is very short (less than 5-10 minutes), ‘continuous’
mode should be considered. Otherwise, ‘intermittent’ mode should be selected.
There is no need to set this value, if the control is used to control the supply of combustion air.
If used with a damper actuator, set for ‘continuous’ operation.
Menu 13: SET EXHAUST PRE-PURGE
When operating in ‘intermittent’ mode it is important to set the pre-purge. Pre-purge is the period from when there is a
call for heat until the control allows the appliance to start assuming the fan is operating at the proper capacity. The setting
can be anywhere from 0 to 1800 seconds.
There is no need to set this value, if the control is used to control the supply of combustion air.
Menu 14: SET EXHAUST POST-PURGE
When operating in ‘intermittent’ mode it is important to set the post-purge. Post-purge is the period from when the appli-
ance shuts down until the control allows the fan to shut down assuming there are no more products of combustion in the
chimney system. The setting can be anywhere from 0 to 1800 seconds.
There is no need to set this value, if the control is used to control the supply of combustion air.
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3120066 MEC24 US 20210325