Marvair Scholar III™ VAISA I&S Manual 03/2019 Rev. 8
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1.15 START-UP PROCEDURE
A. On VAISA models with two stage compressors, only the cooling mode operates in two
stages. Mechanical heating (compressor) is a single stage as is the dehumidification
mode.
1. Turn the disconnect in the Scholar III™ unit to “OFF” position and double check
all electrical connections before applying power.
2. Set the remote thermostat system switch to “OFF” position. The blower switch
should be in “AUTO” position.
3. Check the voltage supply to the disconnect. If voltage readings are appropriate,
proceed with start-up. (See Figure 13 for acceptable voltage ranges.) If voltage
readings are not appropriate, check the power leads at the disconnect and the
main breaker in the mechanical room. Take appropriate corrective action to
supply sufficient voltage to the Scholar III™ disconnect.
Figure 13. Voltage Limitations
4. Turn the Scholar III™ heat pump disconnect to “ON” position.
5. Please refer to the thermostat instructions for configuration and start-up of units
with 2-stage compressors.
a. Check to see that when the heat pump comes on that the air coming out
the discharge grille is cooling. Let unit run for five minutes in this mode.
If heat pump continues to run and provide cooling, this verifies that the indoor
blower, compressor and outdoor blower are all running.
b. Now slowly raise the cooling set point up toward room temperature until the
pump compressor and outdoor blower motor turn off. This will be audible.
The indoor blower will continue to run and turn off after 90 seconds.
Example: VAI 36 HP A
Voltage
Electrical Rating Designations*
A
C
D
Nominal Voltage
208/230 208/230
460
Phase
1
3
3
Minimum Voltage
197
197
414
Maximum Voltage
253
253
506
* Letters refer to model number code designations.
