Capacity Balance Point - Mitsubishi Electric PAAA18AA1 Installation Manual

Use Mode 8 and Mode 10 settings to select the Economic Balance Point that the PAA unit will use. Mode
may be referred to as indoor unit function code in some other literature. Please refer to the controls product
manual for more information.
Indoor Unit Settings
Mode 8 Mode 10
1 1
1 2
2 1
2 2
3 1
3 2
NOTE
When the PAA unit is connected to a cooling-only unit, configure Mode 8 and Mode 10 for
Furnace Only heating.
Below the Economic Balance Point, only the furnace is used for heating. Above the Economic Balance
Point, either the heat pump or furnace is used for heating.
In cold climates where the PAA unit may be sized for the cooling load rather than the heating load, the
system may not have the capacity to heat the space even at temperatures above the Economic Balance
Point.

15.8.2. Capacity balance point

When the PAA unit is first used and the outdoor air temperature is above the Economic Balance Point, the
kit first tries to heat the space with the heat pump.
If the kit is unable to heat the space (most likely due to insufficient heating capacity at the current outdoor
temperature), the unit records the current outdoor temperature as the Capacity Balance Point and switches
to heating with the furnace.
During subsequent calls for heat, if the outdoor temperature is below either the Capacity Balance Point or
the Economic Balance Point, then only the furnace is used for heating. If the outdoor air temperature is
above both the Capacity Balance Point and Economic Balance Point, then the heat pump tries to heat the
space first.
Capacity Balance Point is incrementally reduced, periodically, until equal to the Economic Balance Point
value.
If Mode 25 = 2 and Mode 27 = 2 (which are the recommended initial settings), the PAA unit turns the fan off
in thermal off.
© 2022 Mitsubishi Electric US, Inc.
PAA-A18, 24, 30, 36, 42AA1/BA1/CA1
(Extended outdoor air temperature)
Balance point
(see Extended Balance Point section below)
-13° C (9° F)
-10° C (14° F)
Furnace Only
-7° C (19° F)
-3° C (27° F)
0° C (32° F)
(default)
92
Outdoor Unit
-24° C (-11° F)
-13° C (9° F)
Furnace Only
-10° C (14° F)
-3° C (27° F)
0° C (32° F)
(default)
Specifications are subject to change without notice.