Classic HVPA & HVPSA M&S 8.09-1
15700 - 12
HVAC Equipment
The second type of switch is a one time limit switch. If it senses a temperature of
300ºF, power is turned off to the elements. This switch does NOT reset when the
temperature drops and must be replaced when it activates.
The number and location of both switches is determined by the power supply and the
kW of the heaters.
M.
Ventilation Blower Fan Speed Control.
Factory setting for the indoor blower
speed is full speed. If a lower speed setting is required, the blower motor speed
control may be adjusted with a slotted screwdriver rotating the speed control as
shown in Figure 3. Reference unit label for minimum required
air flow settings for
specific unit model.
Figure 3. Ventilation Blower Speed Control Adjustment Instructions
N.
Standard Ventilation Control.
The
GreenWheel
®
ERV
ventilation option is
equipped with a
fresh air fan speed control
. The fresh air fan speed control
operates both the ventilation intake and exhaust blowers together.
The
GreenWheel
®
ERV
ventilation option can be equipped with an exhaust fan air
speed control, which controls the ventilation exhaust blower independently of the
fresh air intake blower.
Demand Control Ventilation
. A field or factory installed carbon dioxide sensor
controls the ventilation damper and only opens the damper when CO
2
levels exceed
a specified level. Demand control ventilation saves energy and utility costs by
ventilating the classroom based upon occupancy.
Note: Not available on manual fresh air damper (“B”) configuration.
O.
Outdoor Thermostat.
Factory set at 40°F, this thermostat determines the outdoor
temperature at which the supplemental electric heat turns on. This may be field
adjusted to the desired temperature setting by rotating the adjustment knob.
P.
Low Ambient Control
(Standard on units with economizers, optional on all other
units.) The low ambient control permits mechanical cooling when outdoor ambient
temperatures are low. The control uses a reverse-acting high pressure switch to cycle
the condenser fan motor according to liquid refrigerant pressure conditions. Switch
closure and fan operation occurs when the pressure reaches 400 PSIG. The switch
opens again when the refrigerant pressure falls to 245 PSIG. Therefore, the outdoor
SERIES 706
VARI-SPEED
MOTOR CONTROL
LO
HI
