NFW-50X Manual —
P/N LS10129-001NF-E:C 7/25/2018
141
Monitor Module Operation
HVAC Control
E.2 Monitor Module Operation
E.2.1 HVAC RESTART
The
HVAC RESTART
type code can be assigned to any addressable monitor module for the purpose of resetting (deactivating) the
HVAC SHUTDN control module and turning the fan back on. The
HVAC RESTART
monitor module acts globally throughout the
FACP system and therefore, is not programmed to a particular zone. To program this feature in the FACP:
•
Program the
HVAC RESTART
type code to a monitor module which will be used to deactivate the HVAC SHUTDN control
module and restart the fans (refer to
Type Monitor
under the section titled, “Edit Module Screen for Monitor Module” on page 57).
The HVAC RESTART monitor module does not latch when activated. Pressing a switch connected to the monitor module will deactivate
the HVAC SHUTDN control relay module
only if there no alarm conditions present
. The HVAC SHUTDN control relay module can be
deactivated if trouble conditions exist on the FACP.
E.2.2 HVAC OVRRIDE
The
HVAC OVRRIDE
type code can be assigned to any addressable monitor module for the purpose of overriding or preventing the
HVAC SHUTDN control modules from activating. The
HVAC OVRRIDE
monitor module acts globally throughout the FACP system
and therefore, is not programmed to a particular software zone. To program this feature in the FACP:
•
Program the
HVAC OVRRIDE
type code to the monitor module which will be used to override the HVAC SHUTDN control
module and prevent the fans from turning off (refer to
Type Monitor
under the section titled, “Edit Module Screen for Monitor
The HVAC OVRRIDE monitor module does not latch when activated. Activating a switch connected to the monitor module will over-
ride all HVAC SHUTDN control relay modules in the system, preventing the HVAC SHUTDN modules from activating and causing the
FACP LCD to display an active HVAC OVRRIDE module and turn on the Supervisory LED. Releasing the switch will allow the HVAC
SHUTDN control relay modules to activate with subsequent events, turning off the fans.
As an example, pressing the HVAC OVRRIDE switch with no fire alarms, duct supervisories, photo supervisories, CO alarms, or CO
supervisories in the system will prevent the fans from being turned off when an alarm does occur. As long as the switch is activated, the
fans will not shutdown for any alarms. If the system is still in alarm/supervisory condition when the switch is released, the fans will not
shutdown unless another alarm/supervisory event occurs after the switch is released.
Important!
If an alarm/supervisory event exists in the system and HVAC Shutdown has already occurred, HVAC OVRRIDE will have
no effect on the HVAC SHUTDN control relay modules. HVAC OVRRIDE will prevent HVAC Shutdown from occurring only if it is
initiated prior to an alarm/supervisory condition.
NOTE:
Activation of the HVAC OVRRIDE module causes a supervisory event that will be communicated to the Central Station, if enabled.