Installation, Operation and Maintenance Manual
Marvel Mini
31
Subject to change without notice.
120.9-IM (1218)
alarms for the following sensors The High and Low Limit
Set Points are available under the Alarm Set Points menu
The sensors must be enabled for the High and Low Alarm
Set Point display screens to appear The following sensors
have high and low alarm set point capability:
●
Return Air Temperature
●
Return Air Humidity
●
Supply Air Temperature
●
Duct Pressure
●
Room Pressure
●
Refrigerant Pressure
●
Room Temperature
●
Room Humidity
●
Space Temperature
●
Space Humidity
High Duct Pressure (VAV only)
On system with the VAV option, a factory provided high
duct pressure switch will open when the duct pressure
rises above the field adjustable trip point. If this occurs, all
modes of operation are de-energized and the supply air
blower is de-energized A manual reset of the High Duct
Pressure Switch as well as a manual reset of the Alarm on
the controller is required
OPTIONAL SYSTEM SAFETIES
Outdoor Air Damper End Switch
If the field provided Outdoor Air Damper Actuator has
a Damper End Switch, the Damper End Switch could be
connected to the unit’s controller for Alarm notification and
shut down if the outdoor air damper does not open The
damper and damper actuator must be field installed and
wired back to the optional factory terminal blocks for the
Outdoor Damper End Switch option
If the actuator fails to drive the damper open, an alarm
notification will alert the customer of the damper actuator
failure and the system is locked out from operation There
is a delay for the contact closure that should allow ample
time for the actuator to drive completely open This time
delay has a factory default of 3 minutes Please refer to the
Factory Settings section for details on adjusting this time
delay Once the problem is corrected, the system must be
manually reset through the controller’s user interface
Drain Pan Overflow Switch
The drain pan overflow switch is an optional factory supplied
component. The drain pan overflow switch is water level
detection switch that opens when the water level is too high
in the unit’s drain pan indicating that the condensate drain
may be blocked If there is a blockage in the condensate line,
the rising water level in the condensate drain pan will open
the drain pan switch creating an alarm at the controller The
drain pan overflow switch shuts down cooling preventing
the condensate from overflowing the drain pan. The alarm
will notify the customer of the drain pan overflow condition.
Once the blockage is removed from the condensate drain
line, the system must be manually reset at the controller’s
user interface
Dirty Filter Switch
The dirty filter switch is an optional factory supplied
component. When the air filter becomes dirty and should be
replaced, the contacts on the filter switch will open causing
an alarm at the controller The alarm will be in the form of a
notification recommending that the air filter be changed for
preventive maintenance The system will continue to run in
its current mode of operation. The alarm notification can be
reset through the units user interface
Freeze Stat (Compressor)
If the Compressor Freeze Stat option is ordered, the freeze
stat switch is factory provided, factory installed and wired to
the unit’s controller If the temperature of the evaporator coil
falls below the temperature set point of the freeze stat, the
switch contacts open to the controller providing an alarm
and the controller shuts down the cooling mode of operation
The Freeze Stat switch automatically resets once the
temperature of the evaporator coil rises above the reset
temperature set point of the switch
The system will reset based on the controller’s setup for
reset of the Freeze Stat Alarm The controller’s set-up
for reset to the Freeze Stat Alarm is selectable for either
automatic reset or manual reset As a standard, cooling
mode restarts to provide cooling The controller will retain
the alarm to alert the customer of the coil freezing condition
and that the system should be checked by a technician to
ensure proper operation of the cooling cycle
Automatic reset will automatically reset and restart cooling
mode without resetting the audible or visual alarm so the
customer knows when the unit tripped on Freeze Stat
Cooling will automatically restart once the Temperature
