Furnace Control Board - Johnson Controls YP9C Series Installation Manual

5750151-UIM-G-0423
DANGER
!
The temperature rise, or temperature difference between the return
air and the supply (heated) air from the furnace, must be within the
range shown on the furnace rating plate and within the application
limitations shown in Table 5.
The supply air temperature cannot exceed the "Maximum Supply
Air Temperature" specified in these instructions and on the furnace
rating plate. Under NO circumstances can the furnace be allowed to
operate above the Maximum Supply Air Temperature. Operating the
furnace above the Maximum Supply Air Temperature will cause pre-
mature heat exchanger failure, high levels of Carbon Monoxide, a fire
hazard, personal injury, property damage, and/or death.
Delay taps selection
The set of jumper pins on the control board labeled "DELAY" are used
to set the delay profiles for the furnace. These can be chosen so as to
maximize the comfort and sound levels for various regions of the coun-
try.
Tap A is the default profile. It provides a 30-second ramp-up from zero
airflow to full capacity and a 30-second ramp-down from full capacity
back to zero airflow. Whenever there is a change in airflow mode, such
as from low heat to high heat, the motor will take 30 s to ramp from one
speed to the other.
Tap B is the humid profile. This profile is best-suited for installations
where the humidity is frequently very high during cooling season, such
as in the southern part of the country. On a call for cooling, the blower
will ramp up to 50% of full capacity and will stay there for 2 min, then will
ramp up to 82% of full capacity and will stay there for 5 min, and then
will ramp up to full capacity, where it will stay until the wall thermostat is
satisfied. In every case, it will take the motor 30 s to ramp from one
speed to another.
Tap C is the dry profile. This profile is best suited to parts of the country
where excessive humidity is not generally a problem, where the sum-
mer months are usually dry. On a call for cooling the motor will ramp up
to full capacity and will stay there until the thermostat is satisfied. At the
end of the cooling cycle, the blower will ramp down to 50% of full capac-
ity where it will stay for 60 s. Then it will ramp down to zero. In every
case, it will take the motor 30 s to ramp from one speed to another.
Figure 42: Furnace control board
34
Cooling Speed
Humidifier
Jumper
Terminals
Diagnostic
Light
Tap D is the normal profile, best suited for most of the country, where
neither excessive humidity nor extremely dry conditions are the norm.
On a call for cooling, the motor will ramp up to 63% of full capacity and
will stay there for 90 s, then will ramp up to full capacity. At the end of
the cooling cycle, the motor will ramp down to 63% of full capacity and
will stay there for 30 s, then will ramp down to zero. In every case, it will
take the motor 30 s to ramp from one speed to another.
Humidistat
When a humidistat is installed in the system, the "Humidistat con-
nected?" jumper on the control board should be moved to the "YES"
position. The cooling airflow will then be reduced by 15% whenever the
humidistat indicates high humidity.
Taking a flue gas sample
If it becomes necessary to obtain a flue gas sample for analysis, it is
permissible to drill a small hole in the plastic flue pipe for a sample
probe, provided that the vent piping is PVC and the hole is properly
sealed afterwards. If using a polypropylene vent system, the vent sys-
tems manufacturer test port fitting must be used. DONOT drill a test
port hole in polypropylene piping. Use the following procedure:
1. Drill a 11/32 in. hole in the side wall of the PVC vent pipe. If the hole
is in a horizontal section of the vent pipe, ensure that it is located
away from the bottom where condensation may be flowing back
toward the furnace.
2. Operate the furnace a minimum of (10 min) to ensure stable opera-
tion of the combustion process.
3. Sample the flue gas as necessary to obtain CO readings.
4. Using a 1/8 in. pipe tap, cut threads into the sampling hole of the
PVC pipe.
5. Use high temp RTV as a sealant on the threads of a 1/8 in. brass
MPT plug and insert it 3 turns into the hole to correctly seal it.
EAC
Zoning
Terminals
Jumper
Low
Voltage
Last
Terminals
Error Button
Heat Pump
Jumper
Humidistat
Jumper
Continuous
Fan Speed
Jumper
Test
Button
Johnson Controls Ducted Systems