Special Purpose Unit Modes - Daikin MicroTech II Operation And Maintenance Manual

OM 752-4

Special Purpose Unit Modes

There are some additional UVC modes that are considered special purpose unit
modes. These special purpose modes include Pressurize, Depressurize, Purge, Shut-
down, and Energy Hold Off. These modes force the UVC to perform very specific and
limited functions. Use these with caution and only for short periods as needed.
In each of these special purpose UVC modes, if the space temperature drops below
EHS and the Emergency Heat function is enabled, the UVC is forced into the Emer-
gency Heat mode (see "Emergency Heat Mode (Super State)" on page 17) and then
return, once the Emergency Heat function is satisfied.
Table 9: Actions during special purpose unit modes
Action Indoor air fan (IAF)
Pressurize
Depressurize
Purge
Shutdown
Energy hold off
Pressurize Mode
When in Pressurize mode, the UVC uses the IAF, OAD, and exhaust output as needed to
pressurize the space. The UVC stops all normal heating and cooling but does allow emer-
gency heat if required. The pressurize mode can only be accessed via a network connection.
Depressurize Mode
When in Depressurize mode the UVC will use the IAF, OAD, and exhaust output as
needed to depressurize the space. The UVC stops all normal heating and cooling but
does allow emergency heat if required. The de-pressurize mode can only be accessed
via a network connection or with ServiceTools for MicroTech II Applied Terminal Unit
Controllers (ATS).
Purge Mode
When in Purge mode, the UVC uses the IAF, OAD, and exhaust output as needed to
purge the space. The UVC stops all normal heating and cooling but does allow emer-
gency heat if required. The purge mode can only be accessed via a network connection
or with ServiceTools for MicroTech II Applied Terminal Unit Controllers (ATS).
Shutdown Mode
Shutdown mode is the equivalent of the Off mode, but is an Off mode forced by a net-
work connection. When in Shutdown mode, the UVC stops all normal heating, cooling,
ventilation (OA damper is closed), and fan operation. By default emergency heat is not be
used during the shutdown mode, however, the UVC can be configured (Emergency Heat
Shutdown Configuration) to allow emergency heat operation during shutdown mode. The
shutdown mode can be accessed via a network connection, a binary input to the UVC, or
with ServiceTools for MicroTech II Applied Terminal Unit Controllers (ATS).
Shutdown mode and energy hold off mode are a "stop" state for the unit ventilator. It is not a "power off" state.
Energy Hold Off Mode
The UVC supports an energy hold off state, which when active forces the UVC to stop
all normal heating, cooling and ventilation. Typically used by a network connection to
force the UVC to cease heating, cooling and ventilation when conditions exist where
heating, cooling and ventilation are not required or desired. Energy hold off mode is
very similar to shutdown mode except that energy hold off always allows emergency
heat if required. The energy hold off mode can only be accessed via a network connec-
tion or with ServiceTools for MicroTech II Applied Terminal Unit Controllers (ATS).
Outdoor air damper
(OAD)
High 100% Open
Off Closed
High 100% Open
Off Closed
Off Closed
WARNING
22
d o
esCrIptIon of peratIon
Exhaust fan output
Off
On
On
Off
Off
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