Specifications magic-pak: hw/hwc, Refer to figure 2-4 – Armstrong World Industries HWC PREMIER 183 User Manual
Page 34
SPECIFICATIONS
Magic-Pak: HW/HWC
2-24
SRM-HW/HWC 2/99
Detailed Sequence - HW
(w/Fenwal Triton 2461D Ignition Control)
Refer to Figure 2-4
POWER
Line Voltage
When the service disconnect switch is closed, power is
sent to the unit (unit in standby, no signal from
thermo-
stat
). Power (208 - 230 volts A/C) is supplied to the two
black wires located in the junction block on top of the
unit.
Line voltage will be present at the following locations:
First black wire
1.
L-1
on the
ignition control
2.
Terminal on the
transformer
marked
208V
or
240V
(whichever is being used)
3.
Common terminal on the
blower capacitor
Second black wire
1.
Supplies power to the one side of the
induced
draft blower
2.
Common terminal on the
transformer
3.
L
terminal on the
blower control board
Low Voltage (24 VAC)
With the unit at rest (no call from the
thermostat
), 24
volts A/C will be found at the following points:
1.
Red wire exiting the top of the unit
2.
Terminal marked
NO
on the
limit switch
2.
Terminal marked
24VAC
on the
ignition control
3.
Terminal
R
on the
blower control board
CALL FOR HEAT
Line Voltage
The
thermostat
closes the circuit between
R
and
W
.
The following is the sequence of operation for the line
voltage side of the unit:
1.
Terminal
TH
on the
ignition control
energizes,
causing a relay in the
ignition control
to close.
This sends line voltage to terminal
IND
on the
ignition control
, causing the
induced draft
blower
to start.
2.
When
W
is energized, a 24-volt signal is also sent
to the
W
terminal on the
blower control board
.
Approximately 60 seconds after
W
terminal ener-
gizes, the timer on the
blower control board
closes the heat speed relay on the board. This
sends line voltage to the
H
terminal on the
blower
control board
, which starts the
circulating air
blower
.
3.
The
induced draft blower
and the
circulating air
blower
continue to operate as long as
W
is ener-
gized.
4.
When
W
de-energizes, a relay in the
ignition
control
opens. Terminal
IND
de-energizes and the
induced draft blower
shuts down. Approximately
90 seconds later, the
circulating air blower
also
shuts down.
Low Voltage
The following is the sequence of operation for the low
voltage side of the unit on a heat call:
1.
A call for heat closes the circuit in the
thermostat
between
R
and
W
, sending a 24-volt signal to the
white wire on the unit.
2.
The white wire goes to the
C
terminal on the
limit
switch
.
3.
The 24-volt signal is sent from the
C
terminal
(brown wire) on the
limit switch
to terminal
TH
on
the
ignition control
. This causes the
ignition
control
to close the line voltage relay, starting the
induced draft blower
. When the
induced draft
blower
comes up to speed and creates enough
negative pressure, the
pressure switch
closes.
4.
With the
pressure switch
closed, the 24-volt signal
goes to the
rollout switch
located over the burners.
5.
The 24-volt signal from the
rollout switch
goes to
the terminal marked
P.SW
on the
ignition control
,
causing the
ignition control
to make a trial for
ignition (sparking). Terminal
V1
on the
ignition
control
also energizes at this time, causing the
gas
valve
to open.
6.
At the same time that the
C
terminal on the
limit
switch
energizes, a 24-volt signal is also sent to the
W
terminal on the
blower control board
. This
starts the timer on the
blower control board
.
Approximately 30 seconds after the main burners
ignite, the
blower control board
closes a relay;
this sends line voltage to the
circulating air
blower
, starting the blower.
7.
As long as
W
(white wire) is energized, the unit
continues to operate.
8.
When the heat call is satisfied, the circuit between
R
and
W
is interrupted.