Installation, Operation and Maintenance Manual
Marvel Plus
9
Subject to change without notice.
120.5-IM (1018)
Chilled Water Coil (Option)
If the system has the Chilled Water Coil Option, the chilled
water valve (optional) will be controlled (cycled On / Off
or Modulated) to maintain the supply air temperature set
point based on the cooling demand� The entering water
temperature must be below the chilled water temperature
set point� Cooling Demand is determined by how far the
supply air temperature is above the supply air temperature
set point� The chilled water valve is opened or modulated to
maintain the supply air temperature as close to the supply
air temperature set point as possible�
Freezestat (Option)
Units equipped with the Freezestat option have a freezestat
connected to the refrigerant suction line to monitor outlet
suction temperature from the evaporator coils� If the
temperature falls below the Freezestat fixed set point, a
Freezestat Alarm will be present on the Marvel Plus controller�
This is an auto reset type alarm and will continue to reset
to provide cooling� The alarm on the controller is used to
notify the customer of the evaporator coil frosting/freezing
condition and that technical service/ system maintenance is
required�
Marvel Plus Display Screen Information
Each screen listed below has been described for function
within the system� The screens are only representative
of the possible combinations of functions and will change
depending on whether the various options are enabled�
System Status
Home Screen
U01
13:48 05/01/13
Return Hum >
050.0%
Return Temp >
068.1°F
Supply Temp >
048.2°F
Occupied
System ON
HEAT
This screen shows the time and date, return air humidity
option, return air temperature, supply air temperature, and
the status of the system (Occupied/Unoccupied, System ON
or OFF, HEAT, COOL, HUMIDIFY, DEHUM, etc�)�
Press the or buttons to allow navigation through the
main status display screens�
Blower / Motor Screen
U01
Blower VFD
Pressure >
0.12iwc
Frequency >
47.2Hz
This screen shows the readings for blower and motor
conditions� The pressure reading is the static pressure
reading within the duct system� The Frequency reading is
the position or operating point of the supply air blower motor�
The frequency is the VFD output frequency to the motor
based on the static pressure reading and static pressure
set point� As the static pressure decreases, the VFD will be
modulated by the Marvel Plus Main Board microprocessor
to increase the frequency to the motor which will increase
the air volume bringing it closer to the air pressure set point�
Outdoor Sensor Screen
U01
Outdoor Sensors
Temperature >
061.5°F
Humidity >
042.2%
Air Economizer >
100%
This screen shows the outdoor air conditions� It shows
the outdoor air temperature and outdoor air humidity� The
Outdoor Sensors information screen will appear only with
the Air Side Economizer option
