Description of Operation
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OM 1280-2 • MICROTECH UNIT CONTROLLER
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, Shutdown, 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 Emergency
Heat mode (see “Emergency Heat Mode (Super State)”
on page 18) and then return, once the Emergency Heat
function is satisfied.
Table 8: Actions During Special Purpose Unit Modes
Action
Indoor air fan
(IAF)
Outdoor air damper
(OAD)
Exhaust fan
output
Pressurize
High
100% Open
Off
Depressurize
Off
Closed
On
Purge
High
100% Open
On
Shutdown
Off
Closed
Off
Energy Hold Off
Auto
Auto
Auto
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 emergency
heat if required. The pressurize mode can only be accessed
via a network connection, through the LUI keypad, or with
ServiceTools software.
Depressurize Mode
When in Depressurize mode the UVC uses 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 depressurize mode can only be accessed
via a network connection or through the LUI keypad, or with
ServiceTools software.
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 emergency
heat if required. The purge mode can only be accessed
via a network connection through the LUI keypad, or with
ServiceTools software.
Shutdown Mode
WARNING
Shutdown mode and Energy Hold Off mode are a “stop” state for the unit
ventilator. It is not a “power off” state.
Shutdown mode is the equivalent of the Off mode, but is an
Off mode forced by a network 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, through the LUI
keypad, or with ServiceTools software.
Energy Hold Off Mode
The UVC supports an Energy Hold Off mode. When active,
it forces the UVC to stop all mechanical heating and cooling.
Energy Hold Off mode is used by a network connection to
force the UVC to cease mechanical heating and cooling when
curbing energy usage is desired. In Energy Hold Off mode,
mechanical heat is only allowed in the Emergency Heat mode.
The Energy Hold Off mode is commanded via a network
connection, the LUI keypad or ServiceTools software.
Summary of Contents for MicroTech
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