Specifications magic-pak: hw/hwc – Armstrong World Industries HWC PREMIER 183 User Manual
Page 24
SPECIFICATIONS
Magic-Pak: HW/HWC
2-14
SRM-HW/HWC 2/99
FAILED FLAME SENSE/TRIAL FOR IGNITION
When the
pressure switch
closes and a 24-volt signal
is sent to pin 5 of the 6-pin ignition wire harness, the
spark ignition cable
terminal and pin 4 of the 6-pin
ignition wire harness energize.
1.
As spark voltage is supplied to the
ignitor elec-
trodes
, the
gas valv
e opens and this causes the
burners to ignite.
2.
The
ignition control
continues to energize spark
voltage until a flame sense signal is supplied to the
flame terminal on the
ignition control
.
3.
If a flame sense signal is not received at the flame
terminal on the
ignition control
, the
spark igni-
tion cable
terminal remains energized for 10
seconds.
4.
After the 10-second trial for ignition, the
ignition
control
de-energizes the
spark ignition cable
terminal and pin 4 of the 6-pin ignition wire harness.
This causes the
gas valve
to close and the elec-
trode spark to stop.
5.
Once the 24-volt signal is sent to pin 4 of the 6-pin
ignition wire harness, a 30-second
circulating air
blower
“on” delay starts. After the delay is timed
out, the
circulating air blower
starts.
6.
After the
spark ignition cable
terminal de-ener-
gizes, the
ignition control
initiates a 30-second
combustion blower
inter-purge delay.
7.
After 30-second inter-purge, the
ignition control
energizes the
spark ignition cable
terminal and
pin 4 of the 6-pin ignition wire harness. If the flame
sense signal is received at the flame terminal of the
ignition control
, the unit continues heat call.
8.
If the flame sense signal is not received, the system
goes through three trials following the above
sequence.
9.
After three trials, the system goes into lockout and
only the
limit switch
circuit and
pressure switch
circuit remain energized during the 60-minute
lockout period.
10. If the flame sense is lost during the heat cycle, the
gas valve
de-energizes immediately and the
system goes into the trial sequence.
FAN ON
1.
When the
thermostat
is switched to the “FAN ON”
position, the
R-G
circuit sends a 24-volt signal to
pin 4 of the 5-pin thermostat harness.
2.
The 24-volt signal energizes the cooling speed
relay, sending L1 power to the
ACB COOL
terminal
of the
ignition control
.
3.
L1 power is sent to the
circulating air blower
terminal block, causing the
circulating air blower
to run in cooling speed.
4.
The
circulating air blower
continues to run in
cooling speed until the
thermostat
is switched to
“AUTO”, interrupting the
R-G
circuit.
Note: With the
thermostat
in the “FAN ON” position
during heat call,
ignition control
will not energize
the heat speed relay. The
circulating air blower
continues to run in cooling speed unless the
limit
switch
circuit opens, which would cause the heat
speed relay and the
induced draft blower
relay
to become energized. This would de-energize the
cooling speed relay until either the
limit switch
circuit is closed or the
thermostat
is switched to
the “AUTO” position.