Johnson Controls YP9C Series Installation Manual page 16

5750151-UIM-G-0423
Figure 23: Thermostat chart - two stage heat pump with modulating furnace
Accessory connections
The furnace control will allow power-switching control of various acces-
sories.
Electronic air cleaner connection
Two 1/4 in. (6.4 mm) spade terminals (EAC and NEUTRAL) for elec-
tronic air cleaner connections are located on the control board. The ter-
minals provide 115 VAC (1.0 amp maximum) during circulating blower
operation.
Humidifier connection
Two 1/4 in. (6.4 mm) spade terminals (HUM and NEUTRAL) for humidi-
fier connections are located on the control board. The terminals provide
115 VAC (1.0 amp maximum) during heating system operation.
A mounting hole is provided on the control panel next to the furnace
control board for mounting a humidifier transformer if read.
Humidistat connection
For better humidity control during cooling operation, an external humidi-
stat may be used. When using a external humidistat, put the HUMIDI-
STAT jumper in the YES position. Connect the low voltage wiring as
shown in Figures 19 to 23.
Zoning operation
This furnace may be used in zoning systems, using a separate after-
market zoning control. For use in zoned systems, put the ZONE CON-
TROL jumper on the furnace control board in the "YES" position.
If the Zone jumper is put in the "Yes" position, the heating load logic
switches to a special algorithm for multi-zone homes.
16
1. This algorithm operates at the "low demand" firing rate for 10 min
and then ramps to high fire within 20 min (30 min maximum to get
to 100% firing rate).
2. The special zoning algorithm does not have the Run 2 function, so
the burners will stop firing as soon as there is no call for heating.
Heat pump operation
This furnace may be used in conjunction with a heat pump in dual fuel
applications. For heat pump applications, put the HEAT PUMP jumper
on the furnace control board in the "YES" position. Connect the low volt-
age wiring as shown in Figures 22 and 23, Thermostat Charts. If a two-
stage heat pump is to be used, a two-stage thermostat is required.
If the Heat Pump jumper is in the "YES" position, it indicates that there
is a heat pump present and the furnace is used as a secondary heat
source. In addition, the "YES" Heat Pump jumper allows the system to
read the presence of the "O" terminal signal. In heat pump operation,
the following special algorithm logic applies:
1. Supplemental Heating - When both a "W" signal and a "Y1" signal
are present, the modulating firing rate will operate as normal,
except there will be no Run 2 function, so the burners will stop firing
as soon as the "W" signal is removed.
2. Defrost Cycle - When both a "W" signal and a "Y2" signal are pres-
ent, the modulating firing rate will operate at a constant 80% firing
rate and there will be no Run 2 function, so the burners will stop fir-
ing as soon as the "W" signal is removed.
3. Hot Heat Pump - The "hot" heat pump feature will work when the
control is wired to a two-stage thermostat and a two-stage heat
pump.
4. Hot Heat Pump - The "hot" heat pump feature will not work when
the control is wired to a single-stage thermostat and a two-stage
heat pump.
Johnson Controls Ducted Systems