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Marvair Scholar 2.0 I&S Manual 04/2022 Rev.2
4. MAR8000 thermostat.
See Product Data Sheet for complete description.5.
The
direct digital control
(
DDC
) interfaces with the building automation system
(BAS) is to be defined by the specifier, in consultation with the Marvair
®
sales representative. Marvair will factory install the
DDC
sent by the
DDC
manufacturer, and purchased by the customer.
B. Thermostats for air conditioners or heat pumps with only one stage of heating.
1. Digital, non-programmable thermostat.
1 stage heat, 1 stage cool. Fan switch:
Auto & On. Manual changeover system switch: Cool-Off-Heat. Low temperature
protection. °F or °C selectable. Thirty minute power loss memory retention. For
use with models VAIA only. Marvair P/N 50121.
2. Digital, seven day programmable thermostat.
1 stage heat, 1 stage cool.
Fan switch: Auto & On. Auto changeover. Keypad lockout. Non-volatile program
memory. Title 24 compliant. For use with models VAIA only. Marvair P/N 50123.
3. Digital, non-programmable thermostat.
One stage cool/One stage heat.
Manual or auto changeover. Fan mode: Auto or On. Permanent retention of
settings upon power loss. Field adjustable temperature calibration. Max heat and
minimum cool set points. Adjustable temperature differential. Remote sensor
capable. Keypad lock out. Status LED. °F or °C selectable. For use with models
VAIA only. Marvair P/N 50186.
C. Humidity Controller.
All units with Electric reheat or Hot Gas Reheat must have a method of signaling the
reheat function. If a DDC system is not being used, a Humidity Controller must be
installed.
• Defrost Timer (heat pumps only) -
Adjustable defrost control that is based upon
both time and temperature. The preset time interval is adjustable from 30, 60 or
90 minutes using the HMI screen on the PLC.
• BAS Control Relay -
Provides 24 VAC coil to control operation from Building
Automation System (BAS). Note - an additional BAS control relay can be added
when 120 or 240 VAC coils are required.
IMPORTANT
MINIMUM AIR FLOW IS REQUIRED FOR PROPER OPERATION.
1.05 OPTIONAL CONTROLS
A. All Units Have the Following Control Options Available:
1. Hard Start Kit -
Field installed and used on single phase power models to
overcome hard starting conditions.
Note:
Hard start kits are generally not
recommended for use on scroll compressors.
2. Motorized Fresh Air Damper with Powervent and Greencube
®
ERV
Ventilation -
Equipped with a f
resh air fan speed control
. The fresh air fan
speed control controls the ventilation intake blower, automatically balancing the
intake and exhaust cfm up to 450 cfm.
