Continuous Blower Mode; Continuous Blower Speed Selection From The Thermostat; Heat Pump Mode; Start-Up Procedures - Bryant 395CAV Series Installation, Start-Up, And Operating Instructions Manual

3. Continous blower mode
NOTE: EAC-1 terminal is energized with 115v whenever blower
operates.
When the R-G circuit is made, the blower motor operates on
FAN speed. During a call for heat, the blower stops,
allowing the furnace heat exchangers to heat up more
quickly, then restarts at the end of the 45-sec blower on
delay period at HEAT speed. If jumper is across PL7-6 and
PL7-9, the blower on delay is 66 sec.
The blower reverts back to FAN speed after the heating
blower off-delay is completed.
When the thermostat "calls for cooling," the blower oper-
ates on COOL speed. When the thermostat is satisfied, the
blower operates an additional 90 sec before reverting back
to continuous operation on FAN speed.
4. Continuous blower speed selection from thermostat
To select different continuous blower speeds from the room
thermostat, momentarily turn off the FAN switch or push-
button on the room thermostat for 1-3 sec after the blower
is operating. The control will shift the blower speed from
factory setting of FAN to HEAT speed. Momentarily
turning off the FAN switch again at the thermostat will shift
the continuous blower speed selection from HEAT to
COOL. Repeating the procedure will cause the control to
shift from COOL to FAN speed. The selection can be
changed as many times as desired and is stored in the
memory to be automatically used following a power inter-
ruption.

5. Heat pump mode

When installed with a heat pump, the furnace control
automatically changes the timing sequence to avoid long
blower off time during demand defrost cycles. When the
W-Y1, W-Y/Y2, W-Y1-G, or W-Y/Y2-G thermostat inputs
are received at the same time, the control changes the
blower to HEAT speed or starts the blower if it was off, and
begins a heating cycle. The blower remains on until the end
of the prepurge period, then shuts off until the end of the
ignition warm-up and trial for ignition periods (a total of 24
sec). The blower then comes back on at HEAT speed.
When the W input signal disappears, the control begins the
normal inducer post-purge period and the blower changes to
COOL speed after a 1-sec delay. If the W-Y/Y2-G or
W-Y1-G signals disappear at the same time, the blower
remains on for the selected heating blower off delay period
and the inducer goes through its normal post-purge period.
If the W-Y/Y2 or W-Y1 inputs should disappear, leaving
the G signal input, the blower remains on at HEAT speed
for the selected blower off-delay period and the inducer
remains on for the normal post-purge period. After the
blower off-delay is completed, the control switches the
blower to FAN speed.
Anytime the control senses false flame, the control locks
out of the heating mode. This occurs because the control
cannot sense the W input due to the false flame signal, and
as a result, sees only the Y input and goes into cooling
mode, blower off delay. All other control functions remain
in standard format.
NOTE: EAC-1 terminal is energized whenever blower operates.
HUM terminal is only energized when gas valve is energized
C. Start-up Procedures
1. Purge gas lines—After all connections have been made,
purge the lines and check for leaks.
WARNING: Never purge a line into a combustion
chamber. Never use matches, candles, flame, or other
sources of ignition for the purpose of checking leakage.
Use a soap-and-water solution to check for leakage.
Failure to follow this warning can cause fire, explosion,
personal injury, or death.
2. Component test—The furnace control allows all compo-
nents, except gas valve, to be run for a short period of time.
This feature helps diagnose a system problem in case of a
component failure. To initiate component test procedure,
short (jumper) the TEST 3/16-in. quick connect terminal on
control (behind the Y/Y2 terminal) and the C
terminal on furnace thermostat connection block for ap-
proximately 2 sec. (See Fig. 15.)
NOTE: Component test feature will not operate if any thermostat
signal is present at control.
Component test sequence is as follows.
a. Momentarily jumper TEST and C
LED goes off.
b. LED will display previous status code 4 times.
c. Inducer motor starts and continues to run for entire
component test.
d. Hot surface igniter is energized for 15 sec, then de-
energized.
e. Blower motor operates on FAN speed for 10 sec, then
stops.
f. Blower motor operates on HEAT speed for 10 sec, then
stops.
g. Blower motor operates on COOL speed for 10 sec, then
stops.
h. Inducer motor stops.
3. To operate furnace, follow procedures on operating instruc-
tions label attached to furnace.
4. With furnace operating, set thermostat below room tem-
perature and observe that furnace goes off. Set thermostat
above room temperature and observe that furnace restarts.
D. Adjustments

1. Set gas input rate

Furnace gas input rate on rating plate is for installations at
altitudes up to 2000 ft. Furnace input rate must be within ±2
percent of input on furnace rating plate.
a. Determine natural gas orifice size and manifold pressure
for correct input.
(1.) Obtain average yearly gas heat value (at installed
altitude) from local gas supplier.
(2.) Obtain average yearly gas specific gravity from
local gas supplier.
(3.) Verify furnace model. Table 6 can only be used for
model 395CAV Furnaces.
(4.) Find installation altitude in Table 6.
NOTE: For Canada altitudes of 2000 to 4500 ft, use U.S.A.
altitudes of 2001 to 3000 ft in Table 6.
(5.) Find closest natural gas heat value and specific
gravity in Table 6.
(6.) Follow heat value and specific gravity lines to point
of intersection to find orifice size and manifold
pressure settings for proper operation .
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