Dettson Chinook C15-M-V Instructions D'installation Et Manuel Du Propriétaire page 31

9 CONTROLS
WARNING
Do not apply 24Vac to V/W2 at the furnace
control (this is sometimes done during setup,
troubleshooting and/or
problems). Doing so will damage the thermostat.
9.1 FUSE
A three-amp automotive-style (ATC blade type) fuse is
supplied on the furnace control board. This fuse should
provide protection from short-circuits on the control board
and associated 24 VAC wiring.
Any direct shorts during installation,
maintenance could cause this fuse to blow.
replacement is required, use ONLY a 3 amp. It is located
on the control board. Refer to Figure 15.
9.2 120 VAC TERMINALS
These terminals supply 120 VAC to the furnace control.
Spare terminals are provided for use with electronic air
cleaners and other accessories as needed (Check the
voltage rating of your equipment.)
9.2.1 Electronic air cleaner EAC (E103)
This output is used to energize an electronic air cleaner.
The output will provide 1.0 amp at 120 VAC. This output is
energized any time the blower motor is above 500 CFM.
Airflow below this value is not considered to be enough
for a typical electronic air cleaner to perform properly.
9.2.2 HUM terminal
HUM terminal is only energized when blower is energized
in heating.
It is engaged when 24 VAC is present on the
t-stat therminal of the IFC labeled "HUM STAT"
or a communicating t-stat with humidification and
dehumidification capability is installed with call for
humidification present.
An optional 24VAC humidistat can be installed as shown
in figure 30. With the optional humidistat, two separate
conditions must be met before humidification can begin.
1- There must be a call for heat and the blower must be
engaged and 2- the humidistat must determine that there
is a need for humidification.
Dipswitch S5-1 enables (ON) or desables (OFF) dehum
operation. However it has no affect on humidification
operation. If this switch is set to "ON" and no humidistat
is installed, the cooling airflow will be permanently
reduced by approximately 15% giving less than optimal
while diagnosing
service, or
If fuse
30
performance and possibly causing problems. It is not
recommended to leave this switch in the "ON" position
without a humidistat installed
See both wiring methods in figure 31 and figure 30.
9.3 STEPPER GAS VALVE
CONTROL
The furnaces is equipped with a stepper modulating gas
valve. A five-pin connector is used to control and sense
the gas valve. The valve uses a PWM (Pulse Width
Modulated) signal to control the firing rate. The duty cycle
of this signal is five percent less than the expected firing
rate. For example, if the firing rate is 90%, the PWM
to (and from) the valve will be 85% duty cycle. The
connector also provides the 24 VAC signal to energize
the main valve solenoid.
9.4 CONNECTOR 15-PINS
The 15-pin connector provides connections for a variety
of inputs and outputs to the furnace control. The flame
sense, pressure switches sense and limits sense (Main
Limit, MRLC and HALC) are connected to the I.F.C.
through this connector. Reference the wiring diagram
for the furnace printed in this document or on the
inside of the furnace blower door for pin assignments for
troubleshooting.
9.5 ECM MOTOR CONNECTION
This connector sends and receives messages to and
from the blower motor through a single peer-to-peer
network. The blower motor does not communicate on the
same communications buss as the furnace, condenser
and thermostat. Further, a different communications
protocol is used.
For troubleshooting purposes, follow the wiring diagram
supplied in this manual and on the inside of the furnace
blower door.
9.6 COMMUNICATIONS L.E.D.
"RX" (Green) L.E.D. – This L.E.D. indicates that
communications is being sensed to or from (i.e.:
something on the network is trying to communicate) other
components (e.g. a condenser) on the network. This
L.E.D. will blink randomly any time a message is received
by the furnace control.
five minutes, it can be assumed that there is not valid
communications established. Check wiring to make sure
that all points are connected properly.
Further, if this L.E.D. is on continuously, it is an indication
that mis-wiring has occurred. "STAT" (STATUS) (Red)
L.E.D. – This L.E.D. blinks twice slowly (¼ second ON, ¾
second OFF) upon power-up.
Pressing the learn button for two seconds will cause the
green "RX" L.E.D. to blink rapidly (for a short period) to
If no blinking is seen within