Airflow Settings; Gas Valve; Default Blower Speeds - Johnson Controls YP9C Series Installation Manual

Turn gas off at the ball valve or gas cock on gas supply line
before the gas valve. Find the pressure ports on the gas
valve marked Out P and In P.
1. The manifold pressure must be taken at the port marked OUT P.
2. The inlet gas line pressure must be taken at the port marked IN P.
3. Using a 3/16 in. hexhead wrench, remove the plugs from the inlet
and outlet pressure ports. Connect a 1/8 in. UPT barbed hose fitting
to each pressure port.
4. See Figure 41 for location of pressure regulator adjustment screw
on main gas valve.
5. Turn gas and electrical supplies on and follow the operating instruc-
tions to place the unit back in operation.
6. Use a small slotted screwdriver to turn the regulator adjustment
screw. Adjust the pressure by turning the screw one click at a time
until desired pressure is reached. Wait a few seconds after each
adjustment to allow the pressure to stabilize before making addi-
tional adjustments. This is an electronic adjustment screw that does
not require very much force. Application of excessive force to the
adjustment screw will damage the gas valve.
Main
Regulator
Adjustment
Outlet
Pressure
Tap
Figure 41: Gas Valve
Important: If gas valve regulator is turned clockwise, manifold
pressure is increased. If screw is turned counterclockwise, man-
ifold pressure will decrease.
The adjustment screw has a range of 16 clicks (about ±0.5 in. mani-
fold pressure). There is not a hard stop at the ends of the adjustment
range. When the limit of the adjustment range is reached, the next
click will start over at the other end of the range. For instance, if you
are increasing pressure and reach the upper limit of adjustment the
next click will drop the pressure to the lower limit.
7. After the manifold pressure has been adjusted, re-calculate the fur-
nace input to make sure you have not exceeded the specified input
on the rating plate. See "Calculating the furnace input (natural
gas)".
8. Once the correct Btu (kW) input has been established, turn the gas
valve to OFF and turn the electrical supply switch to OFF; then
remove the flexible tubing and fittings from the gas valve pressure
tap replace the pressure tap plugs.
9. Turn the electrical and gas supplies back on, and with the burners
in operation, check for gas leakage around the gas valve pressure
port for leakage using an approved gas detector, a non-corrosive
leak detection fluid, or other leak detection methods.

Airflow settings

Cooling airflow settings
Table 16: Default blower speeds
Model
HEAT
Number
Jumper
060B12 NOM
080B12 NOM
080C16 NOM
100C16 NOM
Johnson Controls Ducted Systems
Inlet
On/Off
Pressure
Switch
Tap

Default Blower Speeds

COOL FAN SPEED
Jumper Jumper
A L
A L
A L
A L
Table 16: Default blower speeds
100C20 NOM
120D20 NOM
This unit is equipped with an electronically commutated (ECM) blower
motor. The motor and blower are capable of delivering airflow over a
wide range of operating conditions.
The desired cooling airflow may be selected by placing the COOL
jumper on the control board in the desired position A, B, C or D. The "A"
position will give the highest airflow and the "D" position gives the low-
est. Additional fine tuning of the cooling airflow can be done by using
the ADJUST jumper. The nominal ADJUST setting is "A", while the "B"
jumper position will give approximately a 10% increase in airflow over
the "A" position and the "C" ADJUST jumper position will give approxi-
mately a 10% decrease from the "A" position. Consult the blower airflow
tables in this manual for the expected airflow at each speed setting.
The speed should be selected so as to deliver approximately 350-400
CFM per ton of A/C cooling capacity. Use of airflow outside of this range
may result in diminished air conditioning performance and may result in
lower overall energy efficiency and higher electric utility bills. See Table
16 for default cooling blower settings.
Continuous Fan Airflow Settings
The default blower speed for continuous fan operation is L (Low) speed.
This furnace may be operated in continuous fan mode by setting the
wall thermostat FAN switch to ON. To select the desired continuous fan
airflow, set the CONT FAN jumper on the control board to the desired
position. There are three options:
1. With the CONT FAN jumper in the "H" position the blower will run
during continuous fan operation at 100% of the selected high stage
cooling speed.
2. With the CONT FAN jumper in the "M" position the blower will run
during continuous fan operation at 70% of the selected high stage
cooling speed.
3. With the CONT FAN jumper in the "L" position the blower will run
during continuous fan operation at 40% of the selected high stage
cooling speed.
The default position is with the FAN SPEED jumper in the "L" position.
In certain circumstances, it may be necessary to move the continuous
fan speed to a different speed tap. However, doing so is not recom-
mended since it will result in higher than normal electrical energy usage
and higher than normal electric utility bills.
Gas heating airflow settings
The default heating blower speed is shown in Table 16.
This unit is equipped with an electronically commutated (ECM) blower
motor. The motor and blower are capable of delivering airflow over a
wide range of operating conditions. The blower speed used for heating
is controlled by the furnace control board and is set to deliver the airflow
needed for a fixed outlet air temperature. The furnace control board has
a jumper with three possible settings (-10, NOM, and +10) to control the
heating airflow. The jumper is factory set to the NOM position. Moving
the jumper to the -10 position will increase the blower speed during
heating operation to a higher speed that will reduce the outlet air tem-
perature by about 10 degrees (-10 degrees). Moving the jumper to the
+10 position will decrease the blower speed during heating operation to
a lower speed that will increase the outlet air temperature by about 10
degrees (+10 degrees). For the majority of applications, the jumper
should be left in the factory NOM position.
In certain circumstances, it may be necessary to move the heating
blower speed to a different setting. The use of heating airflow on a
speed other than the default speed will result in diminished heating per-
formance.
Measurement of temperature rise
After about 5 min of operation, determine the furnace temperature rise.
Measure the temperature of both the return air and the heated air in the
ducts, about 6 ft (1.83 m) from the furnace where they will not be
affected by radiant heat. Increase the blower speed to decrease the
temperature rise; decrease the blower speed to increase the rise.
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